Relapse and clonal disease in children with aplastic anemia (AA) after immunosuppressive therapy (IST): the SAA 94 experience. German/Austrian Pediatric Aplastic Anemia Working Group

Since the introduction of combined immunosuppressive therapy (IST) into management of aplastic anemia (AA) in childhood response and probability of survival improved. In contrast to bone marrow transplantation (BMT), however, patients after IST are not considered cured as high rates of relapse and development of clonal disease demonstrate. From 11/93 to 9/97 114 children (65 m, 49 f; median age 9.5 y.) from 37 centers in Germany and Austria were registered in the SAA 94 study. 86 patients lacking a matched sibling donor received IST. Most of the patients suffered from very severe (VSAA: PMN < 200/microliter) or severe AA (SAA: PMN < 500/microliter). All patients were treated with combined IST consisting of ALG and Cyclosporin A (CSA). VSAA and SAA patients were additionally treated with G-CSF. Therapy response was evaluated at day 112, after 6, 12 and 18 months. 8/86 patients died, the probability of survival being 87% after 4 years. At d 112 61% of evaluable patients became independent of transfusions (IST response: CR + PR), 13% with normal blood counts (CR). After 6 months 33% showed CR. At 12 and 18 months response improved to 74% resp. 80%, 39% resp. 55% CR. The best response was achieved in the subgroup of VSAA with 90% (PR + CR) and 65% CR after 18 months. 4 patients developed AML 3-19 months after the beginning of IST. In 2/4 pts. an aberrant clone (-7; 5q-) could be detected retrospectively in BM at diagnosis of AA. 3 nonresponders developed chromosomal aberrations (+19; -7, +12; +8) after 4, 12 and 16 months without morphological signs of AML or MDS. Overall 11 relapses occurred at a median time of 12 months (range 5-27 months) after the beginning of IST. 2 of them relapsed under CSA therapy, 2 under tapering of CSA and 7 after cessation of CSA. 7 patients responded again to CSA monotherapy. Overall response rate is 77% with a probability of event free survival (EFS) of 54% after 4 years regarding all complications mentioned as events.

Prevention of CNS recurrence in childhood ALL: results with reduced radiotherapy combined with CNS-directed chemotherapy in four consecutive ALL-BFM trials

BACKGROUND

The introduction of cranial radiotherapy (CRT) has provided efficient control of overt or subclinical meningeosis in acute lymphoblastic leukemia (ALL). Especially due to the long-term toxicity of CRT, reduction or elimination of radiotherapy appeared mandatory after cure rates of more than 70% had been achieved in ALL. The Berlin-Frankfurt-Münster (BFM) Study Group initiated several attempts in certain ALL subgroups to omit or reduce CRT while using more CNS-directed chemotherapy but without extended intrathecal treatment during maintenance therapy. This analysis summarizes the essential results that are in particular relevant because irradiation of the central nervous system (CNS) has been further reduced in the most recent trial ALL-BFM 95.

PATIENTS AND METHODS

More than 4000 patients enrolled between 1981 and 1995 in one of the last four ALL-BFM trials have been analyzed to demonstrate the efficiency of intensive systemic and intrathecal chemotherapy with or without reduced CRT in the prevention of CNS relapses.

RESULTS

In trial ALL-BFM81, it was shown that only in low-risk (LR) patients preventive radiotherapy can be replaced safely by intermediate dose (0.5 g/m2) methotrexate (MHD-MTX). In intermediate risk (IR) patients this attempt failed: IR pts had 8 times more CNS relapses if treated by MHD-MTX without CRT. In the subsequent trial ALL-BFM 83, all pts received MHD-MTX. IR pts were randomly treated with 12 or 18 Gy of preventive CRT which did not result in a significantly different outcome. The results from the subsequent trial ALL-BFM 86, using a more intensive consolidation with high-dose methotrexate (HD-MTX), demonstrated that the elimination of CRT in low-risk ALL, the reduced CRT of 12 Gy for IR, 18 Gy for medium (MR), and the reduced CRT with 18 Gy for high risk (HR) ALL, respectively, was justified: the incidence of relapses with CNS involvement was reduced to less than 5% (Reiter et al. 1994, Blood 84: 3122). When even less intensive preventive CRT (12 Gy for all medium and high risk patients) was used in trial ALL-BFM 90, the rate of CNS-related relapses was again below 5%. HR patients now treated with more CNS-directed chemotherapy had the lowest rate of CNS-related relapses observed so far in the BFM trials, even though CRT was also reduced to 12 Gy. Patients with T-cell ALL were shown to be protected from CNS recurrence by the combination of CRT (12 Gy) and HD-MTX more effectively than by HD-MTX in consolidation and TIT therapy during maintenance, especially if they presented with high WBC as shown in a joint AIEOP/BFM analysis (Conter et al. 1997, JCO 15: 2786). Patients with overt meningeosis which are characterized by a high leukemic cell load at diagnosis had a rate of recurrences that was comparable to that of patients with high WBC but no CNS disease.

CONCLUSION

Low-risk ALL patients can be efficiently prevented from CNS relapse by intensive systemic and intrathecal chemotherapy without CRT. Patients with intermediate or medium risk ALL, including T-cell ALL, did not suffer from more CNS or systemic relapses when CRT was reduced to only 12 Gy. Patients with inadequate response to therapy are at particularly high risk for relapse with CNS involvement. Therefore, more CNS-directed systemic and intrathecal chemotherapy was applied in trial ALL-BFM 90, combined with only 12 Gy cranial irradiation, and improved the control of CNS recurrence. It seems likely that larger subsets of B-precursor ALL can be protected from CNS-related relapse by intensive chemotherapy without extended IT treatment and without CRT. This is being investigated in the ongoing trial ALL-BFM 95.

Impaired renal function and tumor lysis syndrome in pediatric patients with non-Hodgkin's lymphoma and B-ALL. Observations from the BFM-trials

OBJECTIVE

Tumor lysis syndrome and renal failure remain important complications early in the course of therapy for pediatric Non-Hodgkin's lymphoma (NHL), frequently leading to therapeutic alterations. In the presented series, children with NHL and tumor lysis syndrome are retrospectively analysed regarding clinical features of acute renal failure and its implications on therapy.

PATIENTS AND METHODS

From 4/1990 to 10/1997, 1192 patients diagnosed of any form of NHL have been registered in the NHL-BFM trials. 63 of these patients were reported to have suffered from impaired renal function and/or tumor lysis syndrome before or during initial treatment. Clinical data of these patients were analysed regarding diagnosis, stage, tumor mass, therapy and complications.

RESULTS

62 of 63 patients with impaired renal function and/or tumor lysis syndrome were diagnosed of Burkitt's lymphoma or B-ALL; 58 (92%) of these patients had advanced stages of disease and high LDH-levels (> 500 U/l). 43 of 63 patients had already signs of impaired renal function at admission. Hyperuricemia was the commonest cause of impaired renal function. Renal infiltration or enlargement was observed in 27 of 63 patients. 6 patients were diagnosed of urinary tract obstruction. 25 patients required hemodialysis. Despite improved renal function before administration of MTX, 21 of 63 patients suffered from protracted MTX-elimination during the first course of therapy. 7 of 63 patients (11%) with tumor lysis syndrome died of sepsis after the first course of therapy, another two patients died within 48 hours of therapy due to electrolyte imbalances.

CONCLUSIONS

In pediatric NHL-patients, Burkitt's lymphoma and B-ALL appear to be the commonest cause of metabolic complications early in chemotherapy. Patients with advanced stages and large tumor mass are at high risk for renal failure. Impaired renal function predisposes patients to further complications and toxic death. Prophylactic use of urate-oxidase in all patients with advanced stage NHL might limit the incidence of tumor lysis syndrome. Prospective studies on renal function prior to and during therapy are required in order to develop a clinical profile reliably detecting patients at risk for developing renal failure and subsequent complications.

Frequent loss of heterozygosity on the long arm of chromosome 6: identification of two distinct regions of deletion in childhood acute lymphoblastic leukemia

Cytogenetic analysis of childhood acute lymphoblastic leukemia (ALL) identified nonrandom chromosomal abnormalities of the long arm of chromosome 6. Most of the alterations are deletions that are thought to be indicative of the presence of a tumor suppressor gene that is mutated on the remaining allele. These observations led us to consider whether 6q loss may contribute to the pathogenesis of childhood ALL. To define further a region containing this gene, we analyzed the loss of heterozygosity (LOH) of chromosome 6 in 113 primary ALL samples with matched normal DNA using 34 highly informative microsatellite markers. LOH was found in 17 (15%) samples at one or more of the loci, and partial or interstitial deletions of 6q were detected in 11 of these tumors. On the basis of these results, we performed a detailed deletional map and identified two distinct regions of deletion. The first region is flanked by D6S283 and D6S302 loci at 6q21-22. The second region is flanked by D6S275 and D6S283 loci at 6q21. Clinical analysis determined that LOH of 6q was demonstrated both in precursor-B cell ALLs (15 of 93; 16%) and in T cell ALLs (2 of 19; 11%). In addition, 19 patients have been studied at diagnosis and relapse; 18 showed the same 6q21-22 structural abnormality at relapse (normal, 16 patients; LOH, 2 patients) as their initial presentation, suggesting, albeit with a small patient sample size, that 6q21-22 deletions may be an initial event in leukemogenesis and may occur less frequently during the progression of childhood ALL. These data suggest the presence of putative tumor suppressor genes on chromosome arm 6q that are important in the development of both T and precursor-B childhood ALLs. Our map provides important information toward cloning putative ALL tumor suppressor genes.

Prophylaxis and treatment of neoplastic meningeosis in childhood acute lymphoblastic leukemia

The introduction of cranial radiotherapy (CRT) has provided efficient control of overt or subclinical meningeosis in acute leukemia. Especially due to the long-term toxicity of CRT, reduction or elimination of radiotherapy appeared mandatory after cure rates of more than 70% had been achieved in acute lymphoblastic leukemia (ALL). Several large clinical trials of the Berlin-Frankfurt-Münster (BFM) Study Group with more than 3500 patients since 1981 have demonstrated that intensive systemic and intrathecal chemotherapy without or with limited CRT can efficiently prevent central nervous system (CNS) relapses in a large percentage of patients. However, only in low-risk patients prophylactic radiotherapy can be completely and safely replaced by conventional doses of methotrexate. In addition, reduction of chemotherapy in low-risk ALL increased the rate of relapses with CNS involvement. Thus, only a combination of multidrug induction, high-dose methotrexate (HD-MTX) consolidation, and reintensification allowed safe elimination of CRT in low-risk ALL. This approach combined with CRT with 12Gy and 18 Gy in medium and high risk ALL, respectively, reduced the incidence of relapses with CNS involvement to less than 5% (trial ALL-BFM 86). Patients with inadequate response to therapy, or with T-cell ALL, or with overt CNS disease are at particularly high risk for relapse with CNS involvement, and require more systemic and intrathecal chemotherapy combined with cranial irradiation. In B-cell ALL, short intensive chemotherapy pulses including HD-MTX could completely replace radiotherapy. In AML, post-consolidation CRT appears to be advantageous with regard to control of extramedullary as well as systemic relapses.

Down's syndrome in childhood acute lymphoblastic leukemia: clinical characteristics and treatment outcome in four consecutive BFM trials. Berlin-Frankfurt-Münster Group

Clinical characteristics, treatment response and outcome were evaluated in children with Down's syndrome (DS) and acute lymphoblastic leukemia (ALL) as compared to other children with ALL (NDS). Sixty-one DS and 4049 NDS patients, receiving intensive antileukemic treatment during four consecutive trials (ALL-BFM 81, 83, 86 and 90) of the Berlin-Frankfurt-Münster Group (BFM), were retrospectively analyzed. DS and NDS children did not differ with respect to sex, leukocyte count, CNS leukemia and cytogenetic translocations. The DS cohort was slightly older (P=0.04), presented predominantly with the common while lacking the T immunophenotype (P=0.005), had a lower frequency of hyperdiploidy (P=0.004) and tended to have a better initial steroid response (P=0.057). Therapy-associated morbidity especially during high-dose methotrexate and a subsequent need for treatment modification occurred in 43% of all DS patients. Event-free survival (EFS) was slightly worse in children with DS (58+/-8% vs 70+/-1%, P=0.14), mainly due to rather late bone marrow recurrences. However, EFS in DS patients was comparable to the NDS group once they either received treatment with no major modifications (65+9% vs 70+/-1%, P=0.66) or were <6 years of age, irrespectively of therapy modifications (73+/-9% vs 74+/-1%, P=0.7). Cox regression analysis revealed that DS was an adverse prognostic factor for patients having completed therapy (P=0.0107), but was not prognostic at diagnosis (P=0.103). Age > or = 6 years, suboptimal treatment and infectious problems contributed to the slight inferior EFS in children with ALL and Down's syndrome. Therefore, most of these patients can be successfully treated if receiving intensive antileukemic treatment with no major modifications, but they require more sophisticated management of toxicity.

Congress Report: XIX symposium of the International Association for Comparative Research on Leukemia and Related Diseases, Mannheim/Heidelberg, Germany, July 13 - 18, 1997

The XIX Symposium of the International Association for Comparative Research on Leukemia and Related Diseases (IACRLRD, President: Prof. Dr. R. Hehlmann) was held in Mannheim and Heidelberg, Germany, July 13 - 18, 1997. Comparative research in cancer was systematically established in the 1950s. Similarities in morphology, biology and pathology between animal and human leukemias and related diseases and the viral origin of a variety of animal leukemias and related diseases (lymphomas, sarcomas, breast tumors etc.) led to the concept that comparative research should promote the understanding of human leukemias and related diseases. In 1960 the World Health Organization inaugurated the establishment of a World Committee for Comparative Leukemia Research. The first symposium took place in Hannover, Germany, in 1963. After the fifth symposium in Padova, Italy, in 1971 the International Association for Comparative Research on Leukemia and Related Diseases (IACRLRD) was founded to complement the World Committee and to expand the international effort. The history of the symposium shows the evolution from a meeting on animal leukemia viruses into one dealing with viral and genetic aspects of human and animal leukemia and related diseases. The scientific evolution of the Abelson murine leukemia virus with its abl oncogene in the 1970s to what currently appears as the most reliable marker for human chronic myeloid leukemia is merely one example. Comparative research has reached a new dimension with the the recent advances in sequencing of the genomes of a variety of species and of humans. Many genes identified in the human genome and relevant for disease can be found in the genomes of animal species and even in the genomes of bacteria and of yeast. This reminds us that not just human and animal biology but also pathology must be regarded as a continuum of evolution and that much can be learned from comparing the genetic information of different species. Comparative genome research will allow conclusions to be drawn from principles recognized in animal species which are relevant to human diseases. It is likely that the application of comparative research to genome analysis will provide basic new insights in molecular medicine into the function of living beings for both animal species and humans. The current revolution in genomics is the latest phase in a rich history of medical progress related to the comparative approach. Meetings and organizations that have grown out of IACRLRD, include, at least to some extent: the Meeting of the International Human Retrovirology Association, the Gallo Lab Meeting , the Feline Retrovirus Meeting, the Cold Spring Habor Retrovirus Meeting, international and regional AIDS meetings, and many others. The XIX symposium in Mannheim included five memorial lectures, seven plenary sessions, 18 parallel sessions, two round table discussions and a public forum. In addition, six associated satellite symposia were held. The general meeting, attended by participants from 27 countries, integrated thematically contributions of genetic, cellular, and viral factors toward the development of leukemia and lymphoma and sought unifying concepts in leukemogenesis.

Periprosthetic mineralization around cementless total hip endoprosthesis: longitudinal study and cross-sectional study on titanium threaded acetabular cup and cementless Spotorno stem with DEXA

In a prospective longitudinal study over 2 years and a separate cross-sectional study more than 5 years after operation, we analyzed periprosthetic bone mineral density (BMD) after cementless total hip arthroplasty (THA) (press-fit cementless Spotorno stem, Mecron threaded acetabular cup) by dual-energy X-ray absorptiometry (DEXA). BMD was analyzed in a longitudinal prospective study (n = 53 patients: 29 women, 24 men) and in a separate cross-sectional study (n = 23 patients: 13 women, 10 men) with good clinical outcome (Merle d' Aubigne score > 12). Regions of interest were defined according to Gruen (ROI 1-7) and as netto average ROI (NETAVG I) for the periprosthetic femur, and according to De Lee and Charnley (ROI I-III) and as NETAVG II for the periprosthetic acetabulum. BMD during follow-up was compared with immediate postoperative values of the affected limb. Mean precision error (CV%) was 2.6 +/- 0.5% for ROI 1-7 and 1.3 +/- 0.9% for ROI I-III. BMD significantly decreased in the periprosthetic femur and acetabulum during the first 3 months after operation. At the femur, BMD (NETAVG I) for women and men, respectively, was 92.4% and 87.5% at 6 months, then 89.4% and 96.2% at 2 years. ROIs around the proximal stem showed the lowest absolute values and decreased most during follow-up (to 79.9% ROI 1 and 68.2% ROI 7, respectively). Mineralization around the cup (NETAVG II), respectively, amounted to 81.1%, 82.6% at 6 months, then 80.1% and 93.8% at 2 years. The medially placed ROI II demineralized most (respectively, 72.1% and 76.7%). More than 5 years after THA, BMD in the femur showed little change, but decreased significantly to 76.4% and 79.1%, respectively, around the cup (NETAVG II). DEXA is a useful method for analyzing changes of mineralization around cup and stem of cementless THA. The results reflect the different stress on the periprosthetic bone after implantation of THA in defined ROIs, supporting earlier reported good clinical results of the Spotorno stem and increased loosening rate of threaded acetabular cups after 5 years.

Should a platelet limit of 600 x 10(9)/l be used as a diagnostic criterion in essential thrombocythaemia? An analysis of the natural course including early stages

In order to evaluate the natural history of essential thrombocythaemia (ET), clinical data and prognostic factors of 143 patients with ET were retrospectively analysed (mean observation time 6.1 +/- 4.6 years). In 42 patients the early phase of the disease with initial platelet counts between 250 and 600 x 10(9)/l was assessed. In most early cases, ET was suggested by clinical symptoms (79%) and increased megakaryopoiesis (95%) with abnormal megakaryocytes in bone marrow histology (n = 34) and cytology (n = 5). Other myeloproliferative disorders and reactive thrombocytosis were excluded according to the diagnostic criteria of the Polycythemia Vera Study Group. During follow-up of the 38 early cases not treated cytoreductively at diagnosis, the platelet counts increased to >600 x 10(9)/l in 28 patients (74%) and remained between 450 and 600 x 10(9)/l in 10 patients (26%). In primarily asymptomatic patients (n = 46) with initial platelet counts above (n = 37) and below 600 x 10(9)/l (n = 9) the rates of increase of symptomatic patients were similar at about 7% per year. No influence of the initial platelet count on survival was seen in multivariate analysis of prognostic factors which included all 143 cases. Survival was mainly influenced by the rate of ET-related complications during follow-up (P = 0.002). Analysing the influence of cytoreductive therapy on symptom-free survival, platelet reduction benefited patients under 60 years (19 cytoreductively treated v 65 untreated patients, P = 0.075). The results demonstrate the possible clinical relevance of the early stages of ET and suggest that the features of pathologic megakaryopoiesis in the bone marrow are a more reliable diagnostic criterion than a definite platelet limit. Therefore, further therapeutic studies should include all stages of the disease and all age groups.

The rate and kinetics of molecular response to donor leucocyte transfusions in chronic myeloid leukaemia patients treated for relapse after allogeneic bone marrow transplantation

We have assessed the molecular response of 30 consecutive patients with chronic myeloid leukaemia (CML) treated for relapse after allogeneic bone marrow transplantation (BMT) by donor leucocyte transfusions (DLT). Response was evaluated by qualitative nested and quantitative competitive RT-PCR for BCR-ABL mRNA at various time intervals before and after DLT. The probability of attaining molecular remission at 2 years was 61% (95% CI 42-78%). Disease state at the time of DLT was significantly associated with response: molecular remission was achieved for 9/10 (90%) patients treated early (cytogenetic or molecular relapse) compared to only 8/20 (40%) patients treated late (haematological relapse; P = 0.009). The Kaplan-Meier estimates of molecular remission at 2 years post DLT for patients treated in early or late relapse were 86.6% and 47.3% respectively (P = 0.004). The median time interval from DLT to molecular remission was 11.0 months (range 2.5-32). Molecular remissions were durable for most (15/17) patients (median follow-up 21.2 months; range 0-55). Two patterns of molecular response were found: a very rapid decline after an initial lag phase or a more gradual decline over a period of several months. We conclude that molecular monitoring is a sensitive indicator of response to DLT; different kinetics of molecular response may reflect disease heterogeneity or differences in the mode of action of DLT.

[Periprosthetic mineral density in cement-free hip replacement arthroplasty]

SUBJECT

We analysed the periprosthetic bone mineral density (BMD) in a prospective longitudinal study over two years after operation and in a separate cross-sectional study more than five years after implantation of cementless total hip arthroplasty (CLS-stem, Mecron threaded acetabular cup) by using dual-energy X-ray absorptiometry (DEXA).

MATERIALS AND METHODS

In n = 53 patients (29 women, 24 men) we analysed the periprosthetic BMD prospectively in certain periods. All patients had an uncomplicated postoperative course and good clinical outcome (Merle d'Aubigne score > 12). In the cross-sectional study we analysed 23 patients (13 women, 10 men). Regions of Interest (ROI) were defined according to Gruen et al. for the periprosthetic femur and to De Lee and Charnley for the periprosthetic acetabulum.

RESULTS

BMD significantly decreases in the periprosthetic femur as well as in the periprosthetic acetabulum during the first three months. In men BMD reaches its lowest values between six months (femur) and one year (acetabulum) after operation and then increases to 96.2% at the femur and 93.8% at the acetabulum. In women BMD decreases during the entire follow-up to 89.4% at the periprosthetic femur and 80.0% at the periprosthetic acetabulum. In the proximal zones 1 and 7 of the femur and the cranial-medial zone II of the acetabulum we observed the highest decrease of mineralisation. More than five years after implantation of the prosthesis BMD in the femur showed only little changes. On the other side BMD around the threaded acetabular cup significantly decreased to 67.4% in women and 79.1% in men.

CONCLUSION

The results reflect the different stress on the periprosthetic bone after implantation of the prosthesis and fit to earlier reported good clinical results of the CLS-stem and to increased loosening rate of threaded acetabular cups after five years. Analysing changes of mineralisation in cementless total hip arthroplasty DEXA together with the analization scheme according to Gruen at the femur and to De Lee and Charnley at the acetabulum is a useful method and has been reliable in clinical practise.

Abnormalities of chromosome band 8p11 in leukemia: two clinical syndromes can be distinguished on the basis of MOZ involvement

Two distinct leukemia syndromes are associated with abnormalities of chromosome band 8p11. First, a myeloproliferative disorder with features characteristic of both chronic myeloid leukemia and non-Hodgkin's lymphoma and second, an acute myeloid leukemia (AML) with French-American-British (FAB) M4/5 morphology and prominent erythrophagocytosis. The two syndromes are exemplified by a t(8;13)(p11;q12) and a t(8;16)(p11;p13), respectively, but cytogenetic variants of both have been described. Recently, the t(8;16) has been cloned and shown to fuse the MOZ gene at 8p11 to the CBP gene at 16p13. We have used fluorescence in situ hybridization (FISH), Southern blotting, and reverse transcriptase-polymerase chain reaction (RT-PCR) to refine the 8p11 breakpoint in three cases with t(8;13)(p11;q12) and in a single case of AML-M5 with a clinical picture apparently identical to that found in patients with a t(8;16), but characterized by an inv(8)(p11q13). FISH analysis was performed with several 8p11 CEPH yeast artificial chromosome (YAC) clones. YAC 782H11 was centromeric to the one case with t(8;13) tested, but was telomeric to the inv(8). YAC 847B12 was telomeric to both the t(8;13) and the inv(8), whereas YAC 829D12 was centromeric to the t(8;13), but split by the inv(8). Southern blotting and PCR of YAC 829D12 showed that it contained the MOZ gene. A 900-bp MOZ fragment encompassing the published t(8;16) breakpoint was amplified by PCR from normal peripheral blood leukocyte cDNA and used to probe Southern blots of patient DNA. A rearrangement was detected in the case with inv(8), but not in any of the three cases with t(8;13). Southern blotting with a CBP probe and RT-PCR with MOZ and CBP primers suggested that the inv(8) does not result in a cryptic MOZ-CBP fusion. It is likely, therefore, that MOZ is fused to a novel gene at 8q13 in this case. We conclude that the t(8;13) breakpoint is flanked by YACs 782H11 and 847B12 and is at least 1 Mb telomeric to MOZ. MOZ is involved, however, in a new variant of the t(8;16).

High incidence of significant bone loss in patients with severe congenital neutropenia (Kostmann's syndrome)

OBJECTIVE

Clinical observation of bone pain, unusual fractures in two patients, and diffuse osteopenia/osteoporosis led us to assess bone mineral content and density in 30 patients with severe congenital neutropenia who were treated with recombinant-methionyl-human granulocyte colony-stimulating factor (r-metHuG-CSF).

STUDY DESIGN

We reviewed roentgenograms in 29 of these 30 patients to evaluate bone loss before and during treatment. In addition, in 17 of the 30 patients, bone mineral status could be assessed by both quantitative computed tomography (Q-CT; n = 16) and dual energy x-ray absorptiometry (DXA; n = 1). In one patient, Q-CT was not possible because of severe vertebral fractures.

RESULTS

Of the 30 patients investigated, 15 had evidence of osteopenia/osteoporosis observed on spine radiographs (n = 5), on Q-CT/DXA (n = 1/n = 1), or on radiographs and Q-CT (n = 8). In 13 of the 30 patients, only a lateral radiograph of the lumbar spine was available, 5 of 13 showing either increased kyphosis and wedging of the vertebrae or compression fractures of the vertebral bodies, indicating severe established osteoporosis. In eight patients, the findings of the spinal radiographs were normal. In nine patients, spinal radiographs were taken before r-metHuG-CSF treatment. Osteoporotic vertebral deformation (n = 3) or reduced bone mass (n = 3) was seen in six of these nine patients. The levels of serum biochemical markers of bone metabolism were all within normal ranges except for mild elevation of the serum alkaline phosphatase level. The degree of spinal bone mineral loss did not correlate with dose and duration of r-metHuG-CSF treatment or with the age or sex of the patients.

CONCLUSIONS

These data indicate a high incidence of bone mineral loss in children with severe congenital neutropenia. The underlying pathogenesis of bone demineralization is not clear. It is more likely that the bone loss was caused by the pathophysiologic features of the underlying disease, but it is possible that r-metHuG-CSF accelerates bone mineral loss.

Molecular monitoring of residual disease in chronic myelogenous leukemia patients after therapy

The degree of tumor load reduction after therapy, which is determined by the degrees of cytoreduction and cytogenetic response, is an important prognostic factor for patients with chronic myelogenous leukemia (CML). Conventional metaphase analysis is considered to be the "gold standard" for evaluating cytogenetic response. The frequency of cytogenetic analysis can be reduced considerably if patients are monitored by molecular methods, such as quantitative Southern blot, fluorescence in situ hybridization (FISH), quantitative western blot, or competitive reverse transcriptase polymerase chain reaction (RT-PCR). Molecular methods can be performed on peripheral blood specimens and are therefore less invasive than cytogenetic analyses of bone marrow metaphases. Furthermore these techniques are applicable to Ph-negative/BCR-AbL-positive cases. Results obtained by Southern blotting, western blotting, and FISH are readily quantifiable but their sensitivity is not generally superior to that of cytogenetic methods. RT-PCR is by far the most sensitive method. Quantitative RT-PCR analysis is the method of choice for monitoring patients after bone marrow transplantation (BMT). Using competitive PCR in patients after BMT, reappearance and/or rising levels of BCR-ABL transcripts can be detected prior to relapse. All complete cytogenetic responders to interferon-alpha are positive for BCR-ABL transcripts. The level of residual disease spans a range over found orders of magnitude. In both interferon-alpha-treated patients and patients after BMT a good correlation between BCR-ABL transcript numbers per microgram of RNA and cytogenetic results has been found. Variables in the competitive PCR assay may be controlled for by quantification of transcripts of the normal ABL gene as an internal standard. We suggest a stepwise strategy for diagnosis and follow-up of CML patients employing molecular methods.

BCR/ABL-negative progenitors are enriched in the adherent fraction of CD34+ cells circulating in the blood of chronic phase chronic myeloid leukemia patients

Philadelphia chromosome-positive (Ph+) hemopoietic cells predominate in patients with chronic myeloid leukemia (CML) in chronic phase, but some Ph presumably normal stem cells persist in most patients. Ph cells are relatively frequent, compared to mature cell populations, in primitive hemopoietic cell populations from CML patients. We have purified CD34+ cells from chronic phase CML blood and separated them into two fractions on the basis of adherence or non-adherence to tissue culture plastic. We also separated CD34+ CML cell populations into HLA-DR(hi) and HLA-DR(lo) fractions and CD38(hi) and CD38(lo) fractions by flow cytometry. The CD34+ cells that adhered to plastic were predominantly CD33-, CD38- and HLA(-)-DR; cells with these phenotypic properties were significantly rarer in the CD34+ non-adherent cell population (P = 0.008-0.02). Expression of p210 BCR/ABL mRNA by adherent, non-adherent, HLA-DR(hi) and HLA-DR(lo)CD34+ cell subpopulations was demonstrated by RT-PCR. Using fluorescence in situ hybridization (FISH) in conjunction with BCR and ABL probes we detected Ph+ and Ph- cells in both adherent and non-adherent CD34+ cell fractions of 15/15 patients studied and in the HLA-DR(lo) or CD38(lo) sorted CD34+ cell fractions. The concentration of Ph- cells in the adherent CD34+ cell fraction was three-fold higher than in the non-adherent fraction (P = 0.001). Ph- adherent cells were detected in untreated CML patients and as late as 6 years after diagnosis of CML in patients treated with hydroxyurea (HU) or interferon-alpha (IFN-alpha). We conclude that whilst appreciable numbers of Ph- primitive hemopoietic progenitors are present in the circulation in untreated patients and also in treated patients in late chronic phase, the majority of cells expressing CD34 but not CD33, CD38 or HLA-DR antigens, are part of the CML clone.

Role of cranial radiotherapy for childhood T-cell acute lymphoblastic leukemia with high WBC count and good response to prednisone. Associazione Italiana Ematologia Oncologia Pediatrica and the Berlin-Frankfurt-Münster groups

PURPOSE

The ALL-BFM 90 and AIEOP-ALL 91 studies share the same treatment backbone and have 5-year event-free survival (EFS) rates close to 75%. This study evaluated the impact of differing presymptomatic CNS therapies in T-cell acute lymphoblastic leukemia (T-ALL) patients with a good response to prednisone (PGR) according to WBC count and Berlin-Frankfurt-Münster (BFM) risk factor (RF).

PATIENTS

A total of 192 patients (141 boys; median age, 7.5 years) with T-ALL, PGR, RF less than 1.7, and no CNS leukemia diagnosed between 1990 and 1995 were enrolled onto the ALL-BFM 90 (n = 123) or AIEOP-ALL 91 (n = 69) study. Presymptomatic CNS therapy consisted of cranial radiation (CRT) and intrathecal methotrexate (I.T. MTX) (11 doses) in the BFM study and of extended triple intrathecal therapy (T.I.T.) (17 doses) in the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) study. Patients were divided into a low-WBC group (WBC count < 100,000/microL) and a high-WBC group (WBC count > 100,000/microL). EFS was compared using the log-rank test.

RESULTS

For patients treated with CRT and I.T. MTX (BFM group), the 3-year EFS rate was 89.8% (SE = 3.5) for 99 patients in the low-WBC group versus 81.9% (SE = 8.2) in the high-WBC group (difference not significant). Conversely, for patients treated with T.I.T. alone (AIEOP group), the EFS rate was 80.6% (SE = 5.6) in 55 patients with a low WBC count versus 17.9% (SE = 11.0) in 14 patients with a high WBC count (P < .001).

CONCLUSION

These data suggest that CRT may not be necessary in PGR T-ALL patients with a WBC count less than 100,000/microL; on the contrary, in patients with a high count, extended T.I.T. may be inferior to CRT and I.T. MTX.

TEL is one of the targets for deletion on 12p in many cases of childhood B-lineage acute lymphoblastic leukemia

Abnormalities of the short arm of chromosome 12 including loss of heterozygosity (LOH) and TEL/AML-1 fusion resulting from a t(12;21)(p13;q22) translocation are frequently observed in childhood acute lymphoblastic leukemia (ALL). We investigated 21 DNA samples of childhood ALL which had LOH at 12p13. Rearrangement of TEL was observed in eight cases and another case showed a homozygous deletion of TEL. Two informative samples with TEL rearrangement had a deletion localized to the 5' region of this gene. The deletion in these two cases includes the helix-loop-helix (HLH) domain. This is consistent with the hypothesis that the normal tel can heterodimerize with the TEL/AML-1 gene product and inhibit the transforming capacity of the chimeric protein. Presumably, loss of the HLH of the normal remaining TEL allele abrogates this tumor suppressor-like function. The case with homozygous deletion of TEL is also consistent with this gene having qualities of a tumor suppressor. One unusual case had T-ALL rather than B-lineage ALL and the leukemic cells had rearrangement of TEL, but they did not have an alteration of the remaining TEL allele suggesting that the etiology of this disease may be different. This analysis further emphasizes the importance of loss of the normal TEL allele in childhood precursor B-lineage ALL.

[Detection of translocation t(8;14)(q24;132) in pediatric Burkitt's lymphomas using "long distance" polymerase chain reaction: a new method for diagnosis of Burkitt's lymphomas]

The pediatric Non-Hodgkin's lymphomas are a heterogeneous group of malignancies of B- or T-cell origin. Approximately half of them are characterized as Burkitt's lymphomas. Typically, one of the reciprocal translocations t(8;14)(q24;q32), t(2;8)(p11;q24) or t(8;22)(q24;q11) is seen in the tumor cell, each involving the protooncogene c-myc on chromosome 8. Characteristically, in most patients the translocation occurs between the distal end of the long arm on chromosome 8 (c-myc) and chromosome 14 (immunoglobulin heavy chain locus, IgH). The breakpoint regions are distributed over a wide range of more than 10 Kb on chr. 8 and over several hundred Kb on chr. 14. With standard-PCR, fragments can only be amplified to a size of about 2 Kb. The development of PCR-applications to generate long products up to 20 Kb now allows a detection of these breakpoints. Several primer pairs from different regions of the IgH-gene and the c-myc-gene were tested in each patient. Until now, 20 patients with Burkitt's Lymphoma or B-ALL characterized by L3 morphology were examined. All patients were treated according the protocols of the NHL-BFM '90 or '95 study. In 11/20 patients, recombinations between chromosomes 8 and 14 could be detected with our primer pairs. In serial dilutions of DNA from malignant cells in DNA from healthy controls, sensitivities of one malignant cell in 2 x 10(4) normal cells could be obtained. This method will now allow us to characterize the involved breakpoints more exactly and to analyze patient samples (blood, bone marrow, aphereses products and residual tumors) during or after therapy for the existence of minimal residual tumor cells.

Absence of IL-6 receptor expression in fresh childhood Burkitt's lymphoma cells and induction of IL-6 receptors by Epstein-Barr virus in vitro

Interleukin-6 (IL-6) is a cytokine which is necessary for the differentiation of activated B cells and growth of early haemopoietic progenitors. It is used for ex-vivo expansion of myeloid progenitors in the setting of high-dose chemotherapy with autologous bone marrow transplantation (BMT). Expression of the IL-6 receptor (IL-6R) was examined in six fresh Burkitt's lymphoma (BL) cell preparations and 12 BL cell lines by reverse transcriptase polymerase chain reaction (RT-PCR) and flow cytometry (FCM). Inducibility of IL-6R mRNA expression by Epstein-Barr virus (EBV) was studied by comparing two uninfected cell lines with the same cell lines infected by EBV The phenotype of the BL cells lines was analysed by FCM and by proliferation assays in the presence of anti-IgM antibodies. None of the fresh BL cells expressed the IL-6 receptor. The BL cell lines expressed varying degrees of IL-6R mRNA and protein. In vitro infection of EBV-negative BL cell lines resulted in up-regulation of IL-6R mRNA. There was no proliferative response of the BL cell lines to IL-6, including the cells that expressed the receptor. Compared to uninfected BL cell lines, EBV-infected cell lines and lymphoblastoid cell lines (LCLs) showed a weaker or no response to anti-IgM antibodies, indicating a more mature phenotype of these cells. We conclude that the IL-6 receptor is not expressed in fresh childhood BLs, but only in BL cell lines. EBV infection in vitro leads to an up-regulation of IL-6R mRNA but not to increased proliferation. This makes growth stimulation of contaminating BL cells in the setting of autologous BMT unlikely.

Molecular response of CML patients treated with interferon-alpha monitored by quantitative Southern blot analysis. German chronic myeloid leukaemia (CML) Study Group

We analysed 459 samples from 206 chronic myeloid leukaemia (CML) patients at diagnosis and during or after treatment with interferon-alpha (IFN-alpha) by quantitative Southern blot analysis for BCR rearrangement. In a minority (2%) of Ph-positive patients, no BCR rearrangement was detectable due to breakpoints outside the major breakpoint cluster region (M-bcr) or possibly due to M-bcr deletions. Results from 235 samples were compared with the proportion of Ph-positive metaphases found in contemporaneous bone marrow specimens analysed by conventional cytogenetics. The rank correlation between both methods was 0.82 (P < 0.001). The proportion of CML cells in samples determined by Southern blot analysis (BCR ratio) was significantly different between cytogenetically-defined minor, partial, and complete response groups (P < 0.001). Empirically-derived cut-off points in the BCR ratio were introduced in order to define molecular response groups for comparison to standard cytogenetic response groups: a BCR ratio of 0% was defined as complete molecular response and ratios of 1-24%, 25-50%, and > 50% were defined as partial, minor, and no molecular response, respectively. Using these cut-off points the concordance between both methods was 67% (P < 0.0001), a major cytogenetic response could be predicted or excluded in more than 90% of cases (P < 0.0001). Our findings demonstrated that quantitative Southern blot was as sensitive as cytogenetics and as peripheral blood samples are suitable for this technique it should be considered as the method of choice for routine monitoring IFN-alpha therapy in CML patients.

Comparative analysis of the impact of risk profile and of drug therapy on survival in CML using Sokal's index and a new score. German chronic myeloid leukaemia (CML)-Study Group

Survival times in chronic myeloid leukaemia (CML) may vary widely depending on the risk profiles of patients. This fact is frequently not, or not sufficiently, considered in evaluating survival in CML, and some studies do not report risk profiles. Therefore we analysed the relative impact of risk profile and therapy on survival using the median survival times of therapy groups and of risk groups of the three-arm randomized German CML Study I (interferon alpha v hydroxyurea v busulphan; median survival times 65 v 56 v 45 months, n = 490, median observation time 70.4 months). The impact of risk profile (Sokal) on survival as determined by the survival difference between high and low risk patients (40 months) was twice the maximum survival difference between treatment groups (20 months). A similar ratio was obtained after stratification for therapy and for risk profile. Since Sokal's index has been reported to prognostically discriminate IFN-treated patients less well than chemotherapy-treated patients, a new score with better discrimination of IFN-treated patients was also used. The results were similar for both scores. We conclude that the risk profile at diagnosis is still more important for survival of CML patients than therapy. Therefore patients should be stratified according to risk profile for comparisons of survival times between studies and treatment arms.

Monitoring the efficiency of interferon-alpha therapy in chronic myelogenous leukemia (CML) patients by competitive polymerase chain reaction

Interferon alpha (IFN-alpha) induces cytogenetic responses of variable degree in patients with CML. We sought to establish the relationship between BCR-ABL transcript numbers measured by competitive two-step reverse transcription polymerase chain reaction (RT-PCR) and cytogenetic status in CML patients treated with IFN-alpha. All 398 samples from 163 patients investigated by RT-PCR were positive for BCR-ABL transcripts. In order to standardize results for variability in RNA and cDNA quality, we quantified total ABL transcripts in each sample as internal control. The BCR-ABL/ABL ratios correlated with the cytogenetic results. Quantitative nested PCR allowed the detection of residual BCR-ABL transcripts in all complete cytogenetic responders on IFN-alpha. We conclude that competitive PCR with internal controls is a reliable method for monitoring patients on IFN-alpha and reduces the need for repeated marrow investigations.

C-kit receptors in childhood malignant lymphoblastic cells

The product of the protooncogene c-kit is the receptor for the hematopoietic cytokine stem cell factor (SCF). C-kit is expressed on leukemic cells of the erythroid, myeloid, and mast-cell lineage and SCF has a proliferative effect on some of these cells. The role of SCF and c-kit in lymphoid malignancies is much less clear. Here we review the role of c-kit in normal lymphopoiesis and summarize its role in lymphoid malignancies. C-kit is expressed in normal lymphopoiesis and its ligand SCF synergizes with IL-7 to enhance the proliferation of B- and T-cell progenitors. In malignant lymphopoiesis, c-kit can also be expressed in B and T-lymphoblastic cells from children with non Hodgkin's lymphoma (NHL) or acute lymphoblastic leukemia (ALL) when analyzed by the highly sensitive reverse transcriptase polymerase chain reaction (RT-PCR). While c-kit receptors were detected by flow cytometric (FCM) analysis on about 40% of fresh T-lymphoblastic biopsy tumor cell preparations or T-lymphoblastic cell lines, no receptors were detected on B-lymphoblastic fresh cells or cell lines from children with B-ALL or Burkitt's lymphoma (BL). Almost all of the lymphoblastic cells expressing c-kit protein responded to recombinant human (rh)SCF with a downregulation of c-kit receptors. A proliferative response was detected only in a minority of these cells. B-ALL or BL cell lines showed no response to rhSCF. Upregulation of c-kit in T-lymphoblastic cells could be demonstrated by the addition of IL-1 beta, TNF-alpha, TGF-beta or A23187, and downregulation by rhSCF or phorbol myristate acetate (PMA). Despite upregulation of c-kit mRNA, protein remained undetectable on B-ALL or BL cells in the presence of A23187. The metabolic state of the cells seemed to influence c-kit expression, since c-kit was upregulated in T-lymphoblastic cells by the addition of new medium. C-kit appears to play a role in the growth of some malignant T-lymphoblastic but not B-lymphoblastic cells.

Quantitative assessment of callus distraction using dual energy X-ray absorptiometry

Bone mineralisation during and after limb lengthening procedures on the femur or tibia using unilateral fixators has been monitored quantitatively using dual energy X-ray absorptiometry (DEXA). We measured the bone mineral density (BMD) prospectively in the newly formed callus, in the bone adjacent to the callus and in the proximal femur. In twenty-one patients we showed a typical course with a peak value at 4-6 weeks after beginning distraction and a minimum value at maximum distraction. In the consolidation period the BMD in the distraction gap increased until the fixator was removed. The BMD in the regenerated bone increased faster in the regions of interest (ROI) opposite the fixator compared to those near it. Dynamisation caused more homogeneous regeneration equalising VBMD in the different ROIs. The BMD in the proximal femur of the leg which was operated on decreased to 67% and in the opposite leg to 87% of the preoperative value. DEXA provides a precise and quantitative assessment of callus and bone mineralisation during limb lengthening and helps in understanding what is happening during these procedures.

Application of long PCR to detect t(8;14)(q24;q32) translocations in childhood Burkitt's lymphoma and B-ALL

BACKGROUND

Burkitt's lymphoma (BL) and B-ALL are characterized by chromosomal translocations juxtaposing the c-myc gene on chromosome 8 to one of the immunoglobulin loci. Translocations involving the immunoglobulin heavy chain (IgH) on chromosome 14 are found in approximately 75%-90% of these tumors. The breakpoint regions are located over a wide range on both chromosomes.

PATIENTS AND METHODS

To detect the translocations, we developed a PCR method to generate long products. After extraction of genomic DNA (QiaAmp System, Qiagen, Hilden, Germany), DNA was amplified using a mixture of Taq and Pwo polymerases (Boehringer Mannheim, Germany). Several primer pairs from the S mu, JH, CH1 and the C alpha regions on IgH and from exon 1 and intron 1 of the c-myc gene were tested in each patient.

RESULTS

Lymphoma cells from 20 children with Burkitt's lymphoma and B-ALL characterized by FAB-L3 morphology were examined. In 11/20 patients, recombinations between chromosomes 8 and 14 could be detected with our primer pairs. PCR products from 800 to 3700 bp in length were obtained reproducibly. After amplification, the products were characterized by restriction enzyme digestion, hybridization, and in part by direct sequencing.

CONCLUSIONS

This PCR-based method will allow us (1) to determine the localization of chromosomal breakpoints in primary tumor material, (2) to investigate whether distinct breakpoints are associated with treatment outcome, and (3) to detect the presence of minimal residual tumor cells during or after therapy.

Sphingomyelin consumption suppresses aberrant colonic crypt foci and increases the proportion of adenomas versus adenocarcinomas in CF1 mice treated with 1,2-dimethylhydrazine: implications for dietary sphingolipids and colon carcinogenesis

Sphingolipids are hydrolyzed in the gastrointestinal tract to ceramide, sphingosine, and other metabolites that can modulate cell growth, differentiation, and apoptosis. To characterize the effects of dietary sphingolipids on colon carcinogenesis, female CF1 mice were administered 1,2-dimethylhydrazine and then fed an essentially sphingolipid-free diet supplemented with 0 to 0.1% (w/w) sphingomyelin (SM) purified from milk. As was found in a previous pilot study (D. L. Dillehay et al., J. Nutr., 124: 615-620, 1994), SM (@ 0.1%) reduced the number of aberrant colonic crypt foci (by 70%, P < 0.001) and aberrant crypts per focus (by 30%, P < 0.003), which are early indicators of colon carcinogenesis. In longer term studies, SM had no effect on colon tumor incidence or multiplicity; however, up to 31% of the tumors of mice fed SM were adenomas, whereas all of the tumors of mice fed the diet without SM were adenocarcinomas. These findings demonstrate that milk SM suppresses the appearance of more advanced, malignant tumors as well as early markers of colon carcinogenesis. Although the sphingolipid content of foods has not been widely studied, several foods (e.g., milk and soybeans) contain the sphingolipid levels used in these investigations; therefore, this class of compounds could be significant contributors to the cancer preventive effects of some foods.

A novel BCR-ABL fusion gene (e6a2) in a patient with Philadelphia chromosome-negative chronic myelogenous leukemia

A novel variant of the chimeric BCR-ABL mRNA transcript was detected in a patient with Philadelphia chromosome-negative (Ph-) chronic myelogenous leukemia (CML) by multiplex reverse-transcription polymerase chain reaction (RT-PCR). Sequence analysis of the fusion region of the amplified cDNA fragment showed an in-frame joining of exon e6 of the BCR gene and exon a2 of the ABL gene, giving rise to an e6a2 BCR-ABL transcript. This finding was confirmed by Southern blot analysis using a specific probe corresponding to intron 6 of the BCR gene, whereas conventional Southern blot for rearrangement of the major breakpoint cluster region (M-bcr) was negative. Western blot studies detected a BCR-ABL protein slightly larger than p185 BCR-ABL. Metaphase fluorescence in situ hybridization showed an insertion of ABL material into the BCR region without reciprocal BCR translocation. The findings in this case show that atypical BCR-ABL transcripts are detectable even in Ph- CML patients without M-bcr-rearrangements. Multiplex PCR using primers that allow for amplification of all known BCR-ABL transcripts is an appropriate method to exclude these rare variants.

Bone quality in the lumbar spine in high-performance athletes

Little is known about the influence of high-performance training on the bone quality of the lumbar spine, in particular, the effects on bone mineral density (BMD) in athletes with high weight-bearing demands on the spine. Measurements were therefore performed in internationally top-ranked high-performance athletes of different disciplines (weight lifters, boxers, and endurance-cyclists). The measurements were carried out by dual-energy X-ray absorptiometry, and the results compared with the measurements of 21 age-matched male controls. The BMD of the high-performance weight lifters was greater than that of the controls by 24% (0.252 g/cm2) on the AP view by 23% (0.200 g/cm2) on the lateral view (P < 0.01), while difference in BMD between the boxers and the controls was +17% (0.174 g/cm2) on the AP view and +19% (0.174 g/cm2) on the lateral view. The BMD of the lumbar spine in all endurance cyclists was lower than that in the controls (AP view -10%, 0.105 g/cm2; lateral view -8%, 0.067 g/cm2; P > 0.05). The results show that training program stressing axial loads of the skeleton may lead to a significant increase of BMD in the lumbar spine of young individuals. Other authors' findings that the BMD of endurance athletes may decrease are confirmed. Nevertheless the 10% BMD loss of cyclists was surprisingly high.

Neuropathology in non-human immunodeficiency virus-infected drug addicts: hypoxic brain damage after chronic intravenous drug abuse

Neuropathological studies were carried out on 180 human immunodeficiency virus-seronegative intravenous drug addicts. The findings in victims of acute heroin intoxication (n = 116) were congestion (99.1%), capillary engorgement (68.1%), and/or perivascular bleeding (68.1%) - hemodynamic processes attributable to toxic primary respiratory failure. In a high percentage of these cases (88%), cerebral edema was also present. In 18 cases of acute heroin intoxication who survived for periods of hours or days, the sole postmortem finding was ischemic nerve cell damages, resembling that typically seen in systemic hypoxia. Semiquantitative analysis revealed nerve cell loss in the hippocampal formation and/or Purkinje cell layer in 26% of the 162 chronic drug abusers. By contrast, in nearly 80% of these cases, the hippocampus showed enhanced expression of glial fibrillary acid protein by astrocytes and/or a proliferation of microglia, demonstrated by CD68 expression. Since such reactive processes are produced by primary neuronal damages, it can be assumed that chronic intravenous drug abuse results in obviously ischemic nerve cell loss. This could be demonstrated in the hippocampus, but it must also occur throughout the whole brain. The demonstration of ischemic nerve cell damage and neuronal loss or secondary reactive alterations has not been described previously.

Randomized study of the combination of hydroxyurea and interferon alpha versus hydroxyurea monotherapy during the chronic phase of chronic myelogenous leukemia (CML Study II). The German CML Study Group

It is the long-term goal of the German CML Study Group and of the Süddeutsche Hämoblastosegruppe (SHG) to improve survival of patients with chronic myelogenous leukemia (CML). In a first randomized study (CML Study I) monotherapies with hydroxyurea or interferon alpha (IFN-alpha) were compared with a standard busulfan regimen with regard to duration of the chronic phase and survival. The main results of this study were published, 1-3 and a long-term follow up is planned. In a second randomized study the effect of the combination of IFN-alpha and hydroxyurea versus hydroxyurea monotherapy on survival is being investigated. This paper provides a first preliminary report on the study concept, patient recruitment, state of documentation and initial patients' characteristics 9 months after closure of the study.

Laboratory tests of iron status: correlation or common sense?

We demonstrate that simple correlation between the various tests of iron status is not sufficient for examining their value in diagnosing iron deficiency (ID). Three degrees of ID are recognized: Iron depletion (ID grade I) is defined by decreased total body iron and normal iron support to erythropoiesis, as diagnosed by decreased storage iron, decreased ferritin, normal sideroblast count, normal zinc protoporphyrin (ZPP), and transferrin saturation >15%. When the iron supply to erythropoiesis becomes insufficient, as diagnosed by transferrin saturation < or = 15%, increased ZPP, and decreased sideroblast count, iron-deficient erythropoiesis (ID grade II) occurs. When finally hemoglobin is below its normal range, iron-deficiency anemia (ID grade III) results. The various tests for ID cannot be compared without taking into account the severity of the deficiency. Depending on the grade of ID examined, the correlation of markers seen in our patients' data varied considerably. We conclude that a "best" marker of ID does not exist. However, the different tests efficiently complement each other by detecting different stages and individually show the clinical extent of ID. Ferritin reflects the iron stores. ZPP indicates whether the ID in a given patient is clinically relevant or not. Finally, the extent of a clinically relevant ID can be assessed by the measured ZPP, hemoglobin concentration, and red cell indices.

Quantitative molecular methods to monitor the response of CML patients to interferon-alpha

Interferon-alpha (IFN-alpha) induces cytogenetic responses of variable degree in patients with CML. We sought to establish the relationship between BCR-ABL transcript numbers measured by competitive two-step reverse transcription polymerase chain reaction (RT-PCR) and cytogenetic status in CML patients treated with IFN-alpha. All 305 samples from 133 patients investigated by RT-PCR were positive for BCR-ABL transcripts. In order to standardize results for variability in RNA and cDNA quality, we quantified total ABL transcripts in each sample as an internal control. The BCR-ABL : ABL ratios correlated well with the cytogenetic results. Quantitative nested PCR allowed the detection of residual BCR-ABL transcripts in all complete cytogenetic responders on IFN-alpha. We conclude that competitive PCR with internal controls is a reliable method for monitoring patients on IFN-alpha and reduces the need for repeated marrow investigations.

Laboratory tests of iron status: correlation or common sense?

We demonstrate that simple correlation between the various tests of iron status is not sufficient for examining their value in diagnosing iron deficiency (ID). Three degrees of ID are recognized: Iron depletion (ID grade I) is defined by decreased total body iron and normal iron support to erythropoiesis, as diagnosed by decreased storage iron, decreased ferritin, normal sideroblast count, normal zinc protoporphyrin (ZPP), and transferrin saturation &gt;15%. When the iron supply to erythropoiesis becomes insufficient, as diagnosed by transferrin saturation &lt; or = 15%, increased ZPP, and decreased sideroblast count, iron-deficient erythropoiesis (ID grade II) occurs. When finally hemoglobin is below its normal range, iron-deficiency anemia (ID grade III) results. The various tests for ID cannot be compared without taking into account the severity of the deficiency. Depending on the grade of ID examined, the correlation of markers seen in our patients' data varied considerably. We conclude that a "best" marker of ID does not exist. However, the different tests efficiently complement each other by detecting different stages and individually show the clinical extent of ID. Ferritin reflects the iron stores. ZPP indicates whether the ID in a given patient is clinically relevant or not. Finally, the extent of a clinically relevant ID can be assessed by the measured ZPP, hemoglobin concentration, and red cell indices.

A randomized phase-III study of the efficacy of granulocyte colony-stimulating factor in children with high-risk acute lymphoblastic leukemia. Berlin-Frankfurt-Münster Study Group

Overall chemotherapeutic treatment results in pediatric acute lymphoblastic leukemia (ALL) are good, with event-free survival (EFS) rates over 70%. However, for a subset of patients characterized by high-risk (HR) features the outcome is less favorable, with EFS rates below 50%. Intensification of chemotherapy may improve the outcome for those patients, but increased toxicity, particularly myelosuppression, limits the escalation of dose intensity. Recombinant methionyl human granulocyte colony-stimulating factor (r-metHuG-CSF) is known to reduce myelosuppression after cancer chemotherapy in adults. The objective of this study was to examine the effect of r-metHuG-CSF on myelosuppression in HR pediatric ALL patients and on the overall response rate to chemotherapy. Patients with HR pediatric ALL were randomized to receive nine alternating cycles of chemotherapy according to the German ALL-Berlin-Frankfurt-Münster 90 protocol either alone or followed by r-metHuG-CSF administered prophylactically at a dose of 5 microg/kg/d subcutaneously. In both groups, the planned interval between chemotherapy courses was a minimum of 21 days. We report here interim results of 34 patients. The incidence of febrile neutropenia (absolute neutrophil count <0.5 x 10(9)/L and oral temperature > or = 38.5 degrees C) was 17% in children receiving r-metHuG-CSF, as compared with 40% in the control group (P = .007). In addition, the median total duration of febrile neutropenia was reduced from 20.3 to 6.2 days per patient (P = .02). Culture-confirmed infections occurred less frequently in the r-metHuG-CSF group (8% v 15%; P = .04), and the total duration of intravenous antibiotic use was significantly reduced from 32.2 days to 18.2 days per patient (P = .02). A tighter adherence to the planned treatment schedule was also facilitated by r-metHuG-CSF (P = .007). With a median follow-up of 3.3 years, the estimated EFS of 4 years is 41% +/- 12%. In conclusion, r-metHuG-CSF administered prophylactically in the interval between chemotherapy courses significantly reduced febrile neutropenia, culture-confirmed infections, and duration of intravenous antibiotic administration and allowed for tighter adherence to the treatment schedule.

Acute lymphoblastic leukemia of childhood: identification of two distinct regions of deletion on the short arm of chromosome 12 in the region of TEL and KIP1

Cytogenetic analysis of acute lymphoblastic leukemia (ALL) of childhood identified nonrandom chromosomal abnormalities of the short arm of chromosome 12. The alterations include deletions that are thought to be indicative of the presence of a tumor suppressor gene that is mutated on the remaining allele. To refine further the chromosomal localization of this gene, we analyzed the loss of heterozygosity (LOH) of chromosome 12 in 100 primary ALL samples using 22 polymorphic markers and identified two distinct smallest common deleted regions on chromosome 12p13. One region is flanked by D12S77 and D12S98 and has a size of 4 cM. Twenty-six percent of informative patients showed LOH in this region. This region may contain the TEL gene. The other region is flanked by D12S269 and D12S308 including the KIP1 gene. Forty-four percent of informative patients showed LOH in this second region. Mutational analysis of KIP1 using polymerase chain reaction-single-strand conformation polymorphism analysis and Southern blot analysis showed no homozygous deletions and point mutations suggesting that the altered gene in this second region is not the KIP1. Clinical data showed that LOH of 12p was demonstrated more frequently in precursor-B ALLs (32 of 80; 40%) than in T-ALLs (1 of 20; 5%) (P = .0027). Furthermore, patients with 12p LOH were younger (P = .013), with a lower DNA index (P = .046), but they had the same survival rates at 3 years. In summary, these data suggest that two different tumor suppressor genes are on chromosome arm 12p, which act separately in the development of childhood precursor-B ALLs. One of the tumor suppressor genes is in the region the KIP1 gene, but our data suggest this gene is not abnormal. The other target is in the region of the TEL gene; and this candidate deserves further study.

Quantification of residual disease in chronic myelogenous leukemia patients on interferon-alpha therapy by competitive polymerase chain reaction

Interferon-alpha (IFN-alpha) induces cytogenetic responses of variable degree in patients with chronic myelogenous leukemia (CML). We sought to establish the relationship between BCR-ABL transcript numbers measured by competitive 2-step reverse transcription polymerase chain reaction (RT-PCR) and cytogenetic status in CML patients treated with IFN-alpha. A total of 250 peripheral blood and 55 bone marrow samples with 127 Philadelphia chromosome positive (Ph+) and 6 Ph-/BCR-ABL+ CML patients were investigated. Twenty-one patients were studied at diagnosis with IFN-alpha, 24 had a complete cytogenetic response, 21 a partial response, 12 a minor response, 26 no response, and 23 were unknown. Using nested RT-PCR, all 305 samples were positive for BCR-ABL transcripts. To standardize results for variability in RNA and cDNA quantity and quality, we quantified total ABL transcripts in each sample as internal control. The validity of ABL as internal control was shown by comparison with glucose-6-phosphate dehydrogenase transcript levels in 145 samples. The median BCR-ABL transcript numbers (and BCR-ABL/ABL ratios expressed as percentages) were 400/micrograms RNA (O.04%) in complete responders, 20,500/micrograms RNA (7.1%) in partial responders, 170,000/micrograms RNA (21.0%) in minor responders, and 430,000/micrograms RNA (58.7%) in nonresponders (P < .001). The cytogenetic results correlated with the BCR-ABL transcript numbers (r = .82; P < .001) and BCR-ABL/ABL ratios (r = .84; P < .001). Grouping the ratios BCR-ABL/ABL as less than 2%, 2% to 14% and greater than 14% to compare with cytogenetic complete response, partial response, and minor/nonresponse, the concordance between the two methods was 82% (chi2 P< .0001). We conclude that quantitative PCR with internal controls is as sensitive and reliable method for monitoring patients on IFN-alpha and reduces the need for repeated marrow investigations.

Mild hypothermia increases blood loss and transfusion requirements during total hip arthroplasty

BACKGROUND

In-vitro studies indicate that platelet function and the coagulation cascade are impaired by hypothermia. However, the extent to which perioperative hypothermia influences bleeding during surgery remains unknown. Accordingly, we tested the hypothesis that mild hypothermia increases blood loss and allogeneic transfusion requirements during hip arthroplasty.

METHODS

Blood loss and transfusion requirements were evaluated in 60 patients undergoing primary, unilateral total hip arthroplasties who were randomly assigned to normothermia (final intraoperative core temperature 36.6 [0.4] degrees C) or mild hypothermia (35.0 [0.5] degrees C). Crystalloid, colloid, scavenged red cells, and allogeneic blood were administered by strict protocol.

FINDINGS

Intra- and postoperative blood loss was significantly greater in the hypothermic patients: 2.2 (0.5) L vs 1.7 (0.3) L, p < 0.001). Eight units of allogeneic packed red cells were required in seven of the 30 hypothermic patients, whereas only one normothermic patient required a unit of allogeneic blood (p < 0.05 for administered volume). A typical decrease in core temperature in patients undergoing hip arthroplasty will thus augment blood loss by approximately 500 mL.

INTERPRETATION

The maintenance of intraoperative normothermia reduces blood loss and allogeneic blood requirements in patients undergoing total hip arthroplasty.

[Modification of bone quality by extreme physical stress. Bone density measurements in high-performance athletes using dual-energy x-ray absorptiometry]

The treatment of osteoporosis is still controversial. Rehabilitation programs which stress strengthening exercises as well as impact loading activities increase the bone mass. On the other side activity level early in life has not been proven to correlate with increased bone mineral content later in life. Little is known on the influence of high performance sports on the bone density especially in athletes with high demands on weight bearing of the spine. In (n = 40) internationally top ranked high performance athletes of different disciplines (n = 28 weight-lifters, n = 6 sports-boxers and n = 6 bicycle-racers) bone density measurements of the lumbar spine and the left hip were performed. The measurements were carried out by dual-photonabsorptiometry (DEXA; QDR 2000, Siemens) and evaluated by an interactive software-programme (Hologic Inc.). The results were compared to the measurements of 21 age-matched male control individuals. In the high performance weight lifters there was an increase of bone density compared to the control individuals of 23% in the Ward's triangle (p < 0.01). The sports-boxers had an increase up to 17% (lumbar spine), 9% (hip) and 7% (Wards' triangle). In the third athletes group (Tour de France-bikers) BMD was decreased 10% in the lumbar spine, 14% in the hip and 17% in the Wards' triangle. Our results show that training programs stressing axial loads of the skeletal system may lead to an increase of BMD in the spine and the hip of young individuals. Other authors findings, that the BMD of endurance athletes may decrease, is confirmed. Nevertheless the bikers BMD-loss of 10 to 17% was surprisingly high.

The importance of charge-separation reactions in tandem mass spectrometry of doubly protonated angiotensin II formed by electrospray ionization: Experimental considerations and structural implications

The occurrence of charge-separation reactions in tandem mass spectrometry of doubly protonated angiotensin II is demonstrated by the use of mass-analyzed ion kinetic energy spectrometry (MIKES) and kinetic energy release distributions (KERDs). Linked scans at a constant B/E severely discriminate against product ions formed by charge-separation reactions. Although the products are significantly more abundant in MIKES experiments, instrumental discrimination still makes quantitation of relative product ion abundances highly inaccurate. The most probable KERs (T m. p.) and the average KERs (T ave.) of the reactions are determined from the KERDs, and these values are compared to the KERs determined from the peak widths at half-height (T 0. 5). The measurement of T 0. 5 is a poor approximation to T m. p. and T ave.. The T m. p. is used to calculate a most probable intercharge distance, which is compared to results from molecular dynamics calculations. The results provide evidence with regard to the mechanisms of fragmentation of multiply charged ions and the location of the charge site in relation to the decomposition reactions.

Allelotype analysis of childhood acute lymphoblastic leukemia

To identify the genetic events that may play an important role in leukemogenesis of childhood ALL, we report for the first time the allelotyping of childhood ALL. Twenty-four cases of childhood ALL were screened for loss of heterozygosity (LOH) using 101 highly polymorphic microsatellite markers, which are distributed among all autosomal chromosomes. For LOH analysis on both chromosomes 9 and 12, 54 childhood ALL samples were examined. The most frequent allelic loss was found on chromosomal arm 9p, where 20 of 50 (40%) informative samples showed LOH. Moreover, nearly 30% of samples that did not have either homozygous deletions or point mutations of the putative tumor suppressor genes CDKN2/INK4A/p16 and INK4B/p15 on chromosomal arm 9p had LOH at D9S171. Loss of chromosomal arm 12p was also frequent (26%). Mutational analysis suggested that the altered gene on 12p is not the cyclin-dependent kinase inhibitor p27/Kip1, which is also on 12p. Several other regions that had LOH included 1p, 4q, 5p, 6q, 7p, 8p, 9q, 10q, 13q, 17p, 17q, 18q, 19q, and 22q. Of 24 patients, 19 (79%) showed allelic loss on at least one chromosomal arm. Samples of two patients (8%) showed LOH on almost all chromosomes. Fractional allelic loss, calculated for each sample as the total number of chromosomal arms lost/total number of arms with information, showed a median value of 0.04 and a mean of 0.123 (range, 0 to 0.95). This fractional allelic loss is lower than those reported for many solid tumors. This analysis shows the extreme power of LOH analysis using microsatellite markers in childhood ALL.

Effect of probenecid on the distribution and elimination of ciprofloxacin in humans

OBJECTIVE

Probenecid-sensitive anion transport systems may be involved in distribution and elimination processes of anionic drugs. The aim of this study was to determine the effect of multiple probenecid treatment on the pharmacokinetic disposition of the zwitterionic fluoroquinolone ciprofloxacin in 12 healthy volunteers.

METHODS

A single intravenous dose of 200 mg ciprofloxacin was given with and without multiple oral administration of probenecid in a randomized crossover fashion. Serial plasma, urine, saliva, tear, and sweat samples were drawn and analyzed for ciprofloxacin and its 2-aminoethylamino-metabolite (M1) by reversed-phase HPLC.

RESULTS

Plasma area under the concentration-time curve and elimination half-life of ciprofloxacin were increased (p < 0.05), and urinary recovery and total and renal clearance decreased (p < 0.05) in the presence of probenecid. Nonrenal clearance and volume of distribution did not differ significantly with and without coadministration of probenecid. Peak plasma concentration, plasma area under the concentration-time curve, and elimination half-life of M1 were increased (p < 0.05) because of the higher amount of M1 formed and the reduced renal clearance (p < 0.05) of the metabolite. Saliva, tear, and sweat exposure were elevated (p < 0.05), but the alterations can be attributed primarily to the different kinetics of ciprofloxacin in plasma.

CONCLUSIONS

Coadministration of probenecid altered the renal excretion and hence the plasma concentrations of ciprofloxacin. Metabolite kinetics and distribution into saliva, tears, and sweat were affected accordingly, but there was no direct effect of probenecid on these processes. This type of drug-drug interaction might be of clinical relevance when ciprofloxacin is combined with drugs eliminated by the organic anion transport system in the kidney tubules.

[Quantitative follow-up of callus distraction with dual-energy roentgen absorptiometry (DEXA)]

With dual-energy X-ray absorptiometry (DEXA), bone mineralization during and after limb-lengthening procedures with unilateral fixators can be monitored quantitatively and precisely with low radiation exposure. We measured prospectively the bone mineral density (BMD) in the newly formed callus, in the bone adjacent to the callus and in the proximal femur in 21 patients with leg lengthening of the femur and/or tibia with unilateral external fixators. Mineralization showed a typical course with a peak value of 0.365 +/- 0.196 g/cm2 (30.9% of the first value) at 6-8 weeks after the beginning of distraction and a minimum value at the time of maximum distraction. In the consolidation period BMD in the distraction gap increased to 1.020 +/- 0.234 g/cm2 (87%) at the time of fixation removal. BMD in the regenerated bone increased faster in regions of interest (ROIs) opposite the fixator compared to ROIs near it. Dynamization of the fixation device led to a 13% increase in mineralization velocity (VBMD). On the other hand, dynamization caused more homogeneous regeneration equalizing VBMD in the different ROIs as well. BMD in the proximal femur of the leg operated on decreased to 67% and in the contralateral leg to 87% of the preoperative value. We consider DEXA to provide a precise and quantitative assessment of callus and bone mineralization during limb lengthening with unilateral fixators. Since we are well aware of the limitation of the technique. DEXA helps to understand what is happening in limb-lengthening procedures by providing quantitative values.

Variable numbers of BCR-ABL transcripts persist in CML patients who achieve complete cytogenetic remission with interferon-alpha

A substantial minority of patients with chronic myeloid leukaemia (CML) achieve a complete response to treatment with interferon-alpha (IFN-alpha), defined as the disappearance of Philadelphia chromosome positive metaphases or, for patients who are Philadelphia chromosome negative but BCR-ABL positive, the disappearance of the leukaemic clone as assayed by Southern blot. We have measured the levels of BCR-ABL transcripts in 20 such patients by quantitative PCR. Results were standardized for both quality and quantity of cDNA by quantification of ABL as an internal control. All 20 patients had evidence of residual disease; the median number of transcripts was 750/micrograms RNA (range 10-22,000) and the median BCR-ABL/ABL ratio was 0.17% (range 0.0008-3.6%). Our findings show that CML has not been eradicated in any patient and that the quantity of residual disease in complete responders may vary by as much as four orders of magnitude.

Absence of c-kit receptor and absent proliferative response to stem cell factor in childhood Burkitt's lymphoma cells

The cytokine stem cell factor (SCF) synergizes with interleukin-7 (IL-7) to enhance the proliferation of pre-B cells. To examine the role of SCF and its receptor, c-kit, in the pathogenesis of pediatric Burkitt's lymphomas (BL), we investigated the expression of SCF and c-kit in BL cells and the mitogenic activity of SCF on BL cells. A panel of 13 BL cell lines and 7 fresh biopsy tumors was investigated. BL cells were stimulated either by Epstein-Barr virus (EBV) infection or by different reagents and cytokines, and expression of SCF and c-kit was studied on the mRNA level by Northern blot analysis and reverse-transcriptase polymerase chain reaction (RT-PCR), followed by Southern blotting. c-kit expression was also studied by fluorescence-activated cell sorting and by crosslinking of digoxigenin-labeled recombinant human SCF to the cell surface. Proliferation of BL cell lines was measured by 3H-thymidine incorporation. Low-level expression of c-kit mRNA was detected in 2 of 13 unstimulated BL cell lines and in 1 fresh BL tumor. One cell line showed upregulation of c-kit mRNA with A23187 and downregulation with phorbol myristate acetate. Neither c-kit nor SCF could be detected in any other cell line under any condition of stimulation as analyzed by Northern blot analysis, RT-PCR followed by Southern blot analysis, crosslinking, and immunofluorescence. No response to SCF was seen in 3H-thymidine incorporation assays. We conclude that most BL cells express neither SCF nor c-kit and that the low-level expression of c-kit in some BL cells most likely has no biologic significance.

Analysis of a family of cyclin-dependent kinase inhibitors: p15/MTS2/INK4B, p16/MTS1/INK4A, and p18 genes in acute lymphoblastic leukemia of childhood

A newly recognized family of proteins that inhibit cyclin-dependent kinases (CDKs) termed cyclin-dependent kinase inhibitors (CDKI) have an important role in regulation of cell-cycle progression. A subfamily of these CDKIs (p15INK4B/MTS2, p16INK4/MTS1, and p18) have a high degree of structural and functional homology and are candidate tumor-suppressor genes. We evaluated the mutational status of the p15, p16, and p18 genes in 103 childhood acute lymphoblastic leukemia (ALL) samples and correlated these results with both their clinical data and additional results concerning their loss of heterozygosity in the region of the p15/p16 genes. Homozygous deletions of the p16 gene occurred extremely frequently in T-ALLs (17/22; 77%), and it was also frequent in precursor-B ALLs (12/81; 15%). Homozygous deletions of the p15 gene were also very frequent in T-ALLs (9/22; 41%), and it occurred in 5 of 81 (6%) precursor-B ALL samples. No deletions of p18 was found in any of the 103 ALL samples. Also, no point mutations of the p15, p16, and p18 genes were detected. We correlated p15/p16 alterations at diagnosis with their clinical characteristics as compared with 2,927 other patients treated similarly. Those with p15/p16 alterations were older; had higher white blood cell counts, often with T-cell ALL phenotype; and more frequently had a mediastinal mass at presentation; but they had the same nonremission, relapse, and survival rates at 5 years as did those patients whose blast cells did not have a p15/p16 deletion. To better understand the extent of alterations affecting chromosome 9p21 (location of the p15/p16 genes), loss of heterozygosity (LOH) was examined at D9S171, which is about 1 megabase proximal to the p15/p16 genes. LOH was detected in 15 of 37 (41%) informative samples. Interestingly, of the 24 informative samples that had no detectable alteration of the p15/p16 genes, 7 samples (29%) had LOH at D9S171. In summary, we show in a very large study that p15 and p16, but not p18, CDKI genes are very frequently altered in ALL; those with p15/p16 alterations are more frequently older children, have higher white blood cells at presentation, and often have a T-cell ALL phenotype. The LOH analysis suggests that another tumor-suppressor gene important in ALL also is present on chromosome 9p21.

Absence of G-CSF receptors and absent response to G-CSF in childhood Burkitt's lymphoma and B-ALL cells

The expression of the granulocyte colony-stimulating factor (G-CSF) receptor in childhood Burkitt's lymphoma (BL) cells, and the mitogenic effect of G-CSF on these cells, was studied in a panel of 13 Epstein-Barr virus (EBV) positive and negative BL cell lines derived from nine children. G-CSF receptor mRNA expression was investigated by Northern blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR). Binding of G-CSF to BL cell lines was measured by chemical crosslinking of 125I-G-CSF, and proliferation by thymidine incorporation. Inducibility of the G-CSF receptor was studied by stimulation with interleukin-1 beta, tumour necrosis factor-alpha, Staphylococcus aureus Cowan A, anti-human IgM, phorbol myristate acetate, calcium ionophore A23187, and by infection in vitro by immortalizing and non-immortalizing strains of EBV. BL cell lines, unstimulated or stimulated by biological reagents or EBV infection, did not bind radioionated G-CSF in crosslinking experiments. No stimulation by recombinant human G-CSF was observed in 3H-thymidine incorporation assays. No G-CSF receptor mRNA was detected by Northern blot analysis or RT-PCR in BL cell lines. It is concluded that G-CSF plays no direct stimulatory role in the growth of these malignant B-cells, making a deleterious influence of G-CSF in the clinical treatment situation unlikely.