Cadherin-11 mRNA transcripts are frequently found in rheumatoid arthritis peripheral blood and correlate with established polyarthritis

Rheumatoid arthritis (RA) synovial fibroblasts hyperexpress the mesenchymal cadherin-11, which is involved also in tumor invasion/metastasis, whereas anti-cadherin-11 therapeutics prevent and reduce experimental arthritis. To test the hypothesis that cadherin-11 is aberrantly expressed in RA peripheral blood, 100 patients (15 studied serially) and 70 healthy controls were analyzed by real-time reverse transcription-PCR. Cadherin-11 mRNA transcripts were detected in 69.2% of moderately/severely active RA, versus 31.8% of remaining patients (p=0.001), versus 17.1% of controls (p<0.0001). Notably, cadherin-11 positivity correlated significantly and independently only with established (>1year) polyarthritis (>4 swollen tender joints), by multivariate logistic regression analysis including various possible clinical/laboratory factors. Rare cells of undefined nature, detected by flow cytometry following CD45(-) enrichment, strongly expressed surface cadherin-11 (estimated 10-50cells/ml of blood) in 5/6 patients with polyarticular established disease versus 1/6 patients with early RA. Studies on the potential pathogenic role of circulating cells expressing cadherin-11 in RA are warranted.

A prospective, cohort, multicentre study of candidaemia in hospitalized adult patients with haematological malignancies

Invasive candidiasis is a life-threatening infection in patients with haematological malignancies. The objective of our study was to determine the incidence, microbiological characteristics and clinical outcome of candidaemia among hospitalized adult patients with haematological malignancies. This is a population-based, prospective, multicentre study of patients ≥ 18 years admitted to haematology and/or haematopoietic stem cell transplantation units of nine tertiary care Greek hospitals from January 2009 through to February 2012. Within this cohort, we conducted a nested case-control study to determine the risk factors for candidaemia. Stepwise logistic regression was used to identify independent predictors of 28-day mortality. Candidaemia was detected in 40 of 27,864 patients with haematological malignancies vs. 967 of 1,158,018 non-haematology patients for an incidence of 1.4 cases/1000 admissions vs. 0.83/1000 respectively (p <0.001). Candidaemia was caused predominantly (35/40, 87.5%) by non-Candida albicans species, particularly Candida parapsilosis (20/40, 50%). In vitro resistance to at least one antifungal agent was observed in 27% of Candida isolates. Twenty-one patients (53%) developed breakthrough candidaemia while receiving antifungal agents. Central venous catheters, hypogammaglobulinaemia and a high APACHE II score were independent risk factors for the development of candidaemia. Crude mortality at day 28 was greater in those with candidaemia than in control cases (18/40 (45%) vs. 9/80 (11%); p <0.0001). In conclusion, despite antifungal prophylaxis, candidaemia is a relatively frequent infection associated with high mortality caused by non-C. albicans spp., especially C. parapsilosis. Central venous catheters and hypogammaglobulinaemia are independent risk factors for candidaemia that provide potential targets for improving the outcome.

FLT3 overexpression in acute promyelocytic leukemia patients without detectable FLT3-ITD or codon 835-836 mutations: a pilot study

BACKGROUND

Activating mutations of the FLT3 receptor tyrosine kinase are common in acute promyelocytic leukemia (APL) but have uncertain prognostic significance. Information regarding FLT3 expression levels in APL without FLT3 mutations is lacking.

MATERIALS AND METHODS

Using RT-PCR, mutation analysis of the FLT3 gene, regarding internal tandem duplications (ITDs) and codon 835-836 point mutations, was performed and real-time PCR was carried out to determine the level of FLT3 expression in 11 APL patients at diagnosis and 5 in haematological remission with molecularly detectable disease.

RESULTS

High levels of FLT3 transcript, at least a 10-fold increase compared to the normal controls, were found at diagnosis in all 3 mutated cases and in 2 patients without detectable FLT3 mutations.

CONCLUSION

FLT3 overexpression can be documented in patients without FLT3 mutations. These patients might benefit from treatment using specific FLT3 tyrosine kinase inhibitors. Larger studies are needed to evaluate the clinical and biological significance of FLT3 overexpression in the absence of FLT3 mutations.

Angiogenesis in Hodgkin's lymphoma: a morphometric approach in 286 patients with prognostic implications

The significance of angiogenesis in Hodgkin's lymphoma (HL) is not well defined. The aim of this study was to evaluate various morphometric characteristics of microvessels in lymph node sections of 286 patients with HL at diagnosis and investigate their relationship with clinicopathologic parameters and prognosis. Microvessel density (MVD), total vascular area (TVA) and several size- and shape-related microvascular parameters were quantitated--after anti-CD34 immunohistochemical staining--in the region of most intense vascularization, using image analysis. An increase in microvessel caliber parameters (area, perimeter, major and minor axis length) and a decrease in MVD were noted with increasing stage. An inverse relationship was recorded between MVD and the number of involved sites (NIS) and LDH. In univariate analysis, overall disease-specific survival was adversely affected by MVD and TVA, whereas inferior failure-free survival (FFS) was associated with the presence of more flattened vessel sections. Multivariate analysis disclosed that the extent of angiogenesis (MVD/TVA), age and the NIS independently affected overall survival. Accordingly, FFS was independently linked to the shape of microvessels and albumin levels or the NIS. In conclusion, our data support the view that angiogenesis in HL provides independent prognostic information, requiring the concomitant evaluation of quantitative and qualitative aspects of microvascular network.

13q deletion in chronic lymphocytic leukemia: characterization of E4.5, a novel chromosome condensation regulator-like guanine nucleotide exchange factor

We report the characterization of a new gene (E4.5) that maps at chromosome band 13q14.3, a chromosomal area frequently deleted in chronic lymphocytic leukemia (CLL) and in other lymphoid malignancies. E4.5 gene encodes for a 4 kb mRNA expressed in various tissues and has an open reading frame of 531 amino acids. The predicted E4.5 protein shows strong homology with the human regulator of chromosome condensation (RCC1) protein, the principal GTP exchange factor for Ran protein. The E4.5 protein contains a BTB domain in its N-terminus, a protein-protein interaction motif. Therefore, we propose that E4.5 is a new member of the RCC1-related guanine nucleotide exchange factor (GEF) family with potent interaction with other proteins and unknown function. Until now, no tumor suppressor genes have been mapped in the 13q14.3 minimal deleted region (MDR) in patients with CLL. It has been proposed that loss of the 13q14.3 MDR may contribute to lymphoid neoplasia by altering the expression/function of genes located on 13q14.3 outside the MDR. The E4.5 is one of these genes with a potential role in the pathogenesis of CLL.

Prospective randomized comparison of vincristine, doxorubicin and dexamethasone (VAD) administered as intravenous bolus injection and VAD with liposomal doxorubicin as first-line treatment in multiple myeloma

BACKGROUND

The combination of vincristine and doxorubicin administered as a continuous infusion via an indwelling catheter together with intermittent high-dose dexamethasone (VAD) is an effective primary treatment for patients with symptomatic multiple myeloma. In order to avoid the need for an indwelling catheter, which imposes logistic problems for outpatient administration, several phase II studies have explored the feasibility and efficacy of VAD-like outpatient regimens. We designed a prospective randomized study to compare the objective response rates of two VAD-like outpatient regimens as primary treatment for symptomatic patients with multiple myeloma.

PATIENTS AND METHODS

Patients were entered in a randomized study regardless of age, performance status and renal function. One hundred and twenty-seven patients received VAD bolus, which consisted of vincristine 0.4 mg i.v., doxorubicin 9 mg/m(2) i.v. and dexamethasone 40 mg p.o. daily for four consecutive days and 132 patients received VAD doxil, which consisted of vincristine 2 mg i.v. and liposomal doxorubicin 40 mg/m(2) i.v. on day 1 and dexamethasone 40 mg p.o. daily for 4 days. The two regimens were administered every 28 days for four courses and in courses 1 and 3, in both arms, dexamethasone was also given on days 9-12 and 17-20.

RESULTS

An objective response was documented in 61.4% and 61.3% of patients treated with VAD bolus and VAD doxil, respectively. Hematological and non-hematological toxicities were mild or moderate and equally distributed between the two treatment arms with the exception of alopecia, which was more common after VAD bolus, and of palmar-plantar erythrodysesthesia, which was more common after VAD doxil.

CONCLUSIONS

Our multicenter trial, which included an unselected patient population, indicated that both VAD bolus and VAD doxil can be administered to outpatients and can provide an equal opportunity of rapid response in many patients with multiple myeloma.

Treatment of Waldenstrom's macroglobulinemia with single-agent thalidomide or with the combination of clarithromycin, thalidomide and dexamethasone

To evaluate the activity of thalidomide in Waldenstrom's macroglobulinemia (WM), 20 patients were treated on a dose schedule that escalated from 200 mg/d to 600 mg/d. On an intention-to-treat basis, five (25%) patients achieved a partial response, which was noted within 3 months of treatment. Adverse effects were common and prevented dose escalation of thalidomide in 75% of patients and led to premature discontinuation of treatment in 35%. We subsequently evaluated the oral combination of clarithromycin (500 mg twice per day), low-dose thalidomide (200 mg once daily), and dexamethasone (40 mg once per week). Our preliminary analysis on 12 previously treated patients indicate activity of this regimen in WM: three patients achieved a partial response and two patients demonstrated monoclonal protein reduction of greater than 25%. This combination was associated with a variety of side effects due not only to thalidomide, but also to corticosteroids and to clarithromycin. Our preliminary data indicate that this combination may be a useful salvage regimen for some patients with heavily pretreated macroglobulinemia.

Deletion analysis of chromosome 13q14.3 and characterisation of an alternative splice form of LEU1 in B cell chronic lymphocytic leukemia

Heterozygous and homozygous deletions of chromosome 13q14.3 are found in 50% of patients with B cell CLL, suggesting the presence of one or more tumour suppressor genes within the deleted region. To identify candidate genes from the region, we constructed a map of 13q14.3 using a combination of genomic and cDNA library screening. The incidence of deletions in CLL patients was 51.5% encompassing a 265 kb region of minimal deletion (RMD) telomeric to markers D13S319. Two CpG islands were identified within the RMD, the telomeric of which is fully methylated whilst the more centromeric is unmethylated. A novel transcript was identified within the RMD that represents an alternative splice version of Leu1. The nine exons of this transcript span a genomic of 436 kb with exon 1 of Leu1 being the common first exon. The remaining exons were shown to be more frequently deleted than Leu1 itself. All splice forms of this transcript were detectable by RT-PCR but Leu1 detected the most abundant message on Northern blotting. Sequence analysis failed to reveal inactivating mutations in patients with heterozygous deletion of 13q14.3, although a polymorphic T to A variant was identified within exon 1 of Leu1 in leukemic and normal controls. As no mutations have been detected for Leu1 or any other transcript so far described, we cannot exclude the existence of control elements within the RMD that may regulate expression of genes lying in this region.

Treatment of Waldenstrom's macroglobulinemia with thalidomide

PURPOSE

We performed a prospective phase II study to assess the activity of thalidomide in patients with Waldenstrom's macroglobulinemia (WM).

PATIENTS AND METHODS

Twenty patients with WM were treated with thalidomide at a starting dose of 200 mg daily with dose escalation in 200-mg increments every 14 days as tolerated to a maximum of 600 mg. All patients were symptomatic, their median age was 74 years, and 10 patients were previously untreated.

RESULTS

On an intent-to-treat basis, five (25%) of 20 patients achieved a partial response after treatment. Responses occurred in three of 10 previously untreated and in two of 10 pretreated patients. None of the patients treated during refractory relapse or with disease duration exceeding 2 years responded to thalidomide. Time to response was short, ranging between 0.8 months to 2.8 months. Adverse effects were common but reversible and consisted primarily of constipation, somnolence, fatigue, and mood changes. The daily dose of thalidomide was escalated to 600 mg in only five patients (25%), and in seven patients (35%), this agent was discontinued within 2 months because of intolerance.

CONCLUSION

Our data indicate that thalidomide has activity in WM but only low doses were tolerated in this elderly patient population. Confirmatory studies as well as studies that will combine thalidomide with chemotherapy or with rituximab may be relevant.

Thalidomide and dexamethasone combination for refractory multiple myeloma

BACKGROUND

Thalidomide is effective in approximately 30% of patients with refractory multiple myeloma. Dexamethasone is active in 25% of patients with disease resistant to alkylating agents. We investigated the combination of thalidomide with dexamethasone as salvage treatment for heavily pretreated patients with multiple myeloma, in order to assess its efficacy and toxicity.

PATIENTS AND METHODS

Forty-four patients with refractory myeloma were treated with thalidomide, 200 mg p.o. daily at bedtime, with dose escalation to 400 mg after 14 days, and dexamethasone, which was administered intermittently at a dose of 20 mg/m2 p.o. daily for four days on day 1-4, 9-12, 17-20, followed by monthly dexamethasone for four days. Patients' median age was 67 years. All patients were resistant to standard chemotherapy, 77% were resistant to dexamethasone-based regimens and 32% had previously received high-dose therapy.

RESULTS

On an intention-to-treat basis twenty-four patients (55%) achieved a partial response with a median time to response of 1.3 months. The thalidomide and dexamethasone combination was equally effective in patients with or without prior resistance to dexamethasone-based regimens and in patients with or without prior high-dose therapy. Toxicities were mild or moderate and consisted primarily of constipation, morning somnolence, tremor, xerostomia and peripheral neuropathy. The median time to progression for responding patients is expected to exceed 10 months and the median survival for all patients is 12.6 months.

CONCLUSION

The combination of thalidomide with dexamethasone appears active in patients with refractory multiple myeloma. If this activity is confirmed, further studies of this combination as second-line treatment for patients resistant to conventional chemotherapy, and as primary treatment for patients with active myeloma, should be considered.

B-cell kinase lyn deficiency in patients with systemic lupus erythematosus

BACKGROUND

To better understand the molecular background of B-cell overactivity characterizing systemic lupus erythematosus (SLE), we examined the expression of the CD22 co-receptor and of kinase Lyn, which are involved in signaling inhibitory pathways, in B cells from patients with SLE.

METHODS

Two-color flow cytometry was used to study the expression of surface antigens on freshly isolated peripheral B cells from patients with SLE, disease-control patients, and healthy volunteers. Intracellular kinases Lyn and Syk were analyzed using Western immunoblots, and differences at the messenger RNA (mRNA) level were evaluated using semiquantitative polymerase chain reaction (PCR).

RESULTS

Expression of B-cell surface CD22 was intact in patients with SLE, but expression of the B-cell kinase Lyn was significantly decreased in resting, as well as in anti-sIgM-stimulated B-cell-enriched cell lysates obtained from 66% of patients with SLE. Lyn deficiency was disease-specific and unrelated to disease activity. Expression of B-cell kinase Syk was similar in all study groups. Semiquantitative PCR revealed that Lyn mRNA was significantly decreased in lupus patients with decreased Lyn protein expression, suggesting that Lyn deficiency may be caused at least in part by defects at the transcription level.

CONCLUSIONS

Decreased expression of Lyn in some patients with SLE represents a B-cell defect that may enhance our understanding of SLE molecular pathogenesis by providing rational therapeutic targets.

Waldenström's macroglobulinemia: clinical features, complications, and management

PURPOSE

To review the clinical features, complications, and treatment of Waldenström's macroglobulinemia, a low-grade lymphoproliferative disorder that produces monoclonal immunoglobulin (Ig) M.

METHODS

A review of published reports was facilitated by the use of a MEDLINE computer search and by manual search of the Index Medicus.

RESULTS

The clinical manifestations associated with Waldenström's macroglobulinemia can be classified according to those related to direct tumor infiltration, to the amount and specific properties of circulating IgM, and to the deposition of IgM in various tissues. Asymptomatic patients should be followed without treatment. For symptomatic patients, standard treatment consists primarily of oral chlorambucil; nucleoside analogs, such as fludarabine and cladribine, are effective in one third of previously treated patients and in up to 80% of previously untreated patients. Preliminary evidence suggests that anti-CD20 monoclonal antibody may be active in about 30% of previously treated patients and that high-dose therapy with autologous stem-cell rescue is effective in most patients, including some with resistance to nucleoside analogs.

CONCLUSION

Waldenström's macroglobulinemia has a wide clinical spectrum that practicing physicians need to recognize early to reach the correct diagnosis. When therapy is indicated, oral chlorambucil is the standard primary treatment, but cladribine or fludarabine can be used when a rapid cytoreduction is desirable. Prospective randomized trials are required to elucidate the impact of nucleoside analogs on patients' survival. A nucleoside analog is the treatment of choice for patients who have been previously treated with an alkylating agent.

Genetics of small lymphocyte disorders

Cytogenetic analysis of small lymphocytes disorders is hindered by the low mitotic activity of the malignant cells. The use of fluorescence in situ hybridization (FISH) allows the detection of chromosomal amplifications, deletions, or translocations at a single-cell level in dividing and resting cells. The use of FISH in combination with other molecular techniques has defined the deletion in band 13q14 as the most common abnormality in chronic lymphocytic leukemia, followed by del (11)(q22-23), trisomy 12, del (17)(p13), and del (6)(q21). The del 13q14 is also found in 70% of mantle-cell lymphomas (MCLs) and in non-Hodgkin's lymphoma (NHL), acute lymphoblastic leukemia (ALL), and multiple myeloma (MM) patients. These findings point to the existence of yet unidentified tumor-suppressor gene(s) at the 13q14 locus, the loss/inactivation of which leads to B-cell neoplasia. Del (17(p13) (involving the p53 tumor-suppressor gene) and del (11)(q22-23) (involving the ataxia-telangiectasia gene [ATM]) seem to be independent prognostic factors for poor survival in chronic lymphocytic leukemia (CLL) patients. In MCL, the t(11;14) involving the bcl-1 gene is found, but data from a bcl-1 transgenic animal model suggest that hyperexpression of bcl-1 is not sufficient for lymphomatogenesis. Similar data are observed in bcl-2 transgenic animals, a finding showing that the bcl-2 hyperexpression observed in t(14;18)-positive follicular lymphoma cells is not sufficient to confer a malignant phenotype. The contribution of other chromosomal abnormalities other than bcl-1 and bcl-2 rearrangements in the pathogenesis of MCL and follicular-cell lymphomas has to be determined.

Monocytes stimulate expression of the Bcl-2 family member, A1, in endothelial cells and confer protection against apoptosis

We have investigated the molecular mechanisms underlying the ability of peripheral blood monocytes to block apoptosis induction in endothelial cells. Monocytes stimulated the expression of the bcl-2 homologue A1 in serum-starved endothelial cells after 6 h of coincubation, with elevated A1 levels persisting for up to 21 h. IL-1 and TNF also stimulated A1 expression at 6 h, but A1 transcript levels fell by 21 h. Direct cellular contact with monocytes was required for stimulation of A1 mRNA in endothelial cells. Stimulation of endothelial cell A1 mRNA by monocytes was not inhibited by anti-beta2 integrin Abs, but anti-platelet endothelial cell adhesion molecule-1 (PECAM-1) mAb reduced A1 transcript levels at 21 h. Studies employing either TNF on its own, or anti-TNF in endothelium/monocyte cocultures showed that TNF plays a role in the early (6-h) stimulation of A1, but is less important for the sustained elevation of A1 levels at 21 h. Serum-starved endothelial cells demonstrated increased survival and decreased apoptosis after coculture with monocytes. IL-10 reduced A1 mRNA expression in, as well as survival of, endothelial cells that were cocultured with monocytes. In comparison with A1, Bcl-2 was expressed at low levels and was up-regulated by monocytes only at 21 h, while neither Bax nor Bcl-xL levels were altered by monocytes. The interaction of monocytes with endothelium during the course of an inflammatory reaction may provide survival signals to endothelial cells.

The human homologue of the Drosophila tailless gene (TLX): characterization and mapping to a region of common deletion in human lymphoid leukemia on chromosome 6q21

Deletion of the long arm of chromosome 6 (6q) is one of the most common chromosomal abnormalities in human hematological malignancies. Two distinct regions of minimal deletion have been identified by loss of heterozygosity studies at 6q25 to 6q27 (RMD-1) and at 6q21 to 6q23 (RMD-2), suggesting the presence of one or more tumor suppressor genes. We have cloned sequences within RMD-2 and screened for novel genes using a combination of direct sequencing, cDNA library screening, and exon trapping. Sequences generated from a cosmid fragment, mapping within RMD-2, showed homology to the Drosophila tailless gene (tll). The human homologue of the Drosophila tailless gene (human tlx; MGMW-approved symbol, TLX) was subsequently cloned from a fetal brain cDNA library. The gene is a member of the steroid nuclear receptor superfamily and is homologous to tll genes from other species that are involved in brain development. TLX is predominately expressed in the brain and maps to RMD-2 at 6q21 between DNA markers FYN and D6S447, in a YAC clone that also contains marker D6S246. The contributions of this gene to human B-cell leukemia and to brain development are unknown at present.

Effects of 2-chlorodeoxyadenosine and gold sodium thiomalate on human bcl-2 gene expression

Aberrant expression of apoptosis-related genes, including the "cell death suppressor gene" bcl-2, may play an important pathogenetic role in cancer and autoimmune diseases, In vivo upregulation of bcl-2 mRNA in synovial lining cells of patients with rheumatoid arthritis but not in patients with osteoarthritis has been recently found. In the present study we investigated whether agents exerting beneficial effects in patients with rheumatoid arthritis, namely the long used Gold Sodium Thiomalate (GST) and the novel immunosuppressive, purine analogue 2-chlorodeoxyadenosine (2-CdA), a lymphocyte apoptosis-inducing agent interfere directly with induction of bcl-2 mRNA expression. The phytohemagglutinin (PHA)-induced in vitro proliferation of normal human peripheral blood lymphocytes was significantly inhibited by non-toxic concentrations of 2-CdA and GST which are within the range of in vivo plasma concentrations in patients receiving the respective treatment. Using mRNA dot-blot analysis and hybridization with an IL-2-specific probe we found that GST, similarly to dexamethasone that served as control, suppressed the PHA-induced IL-2 mRNA accumulation dose-dependently. In contrast, 2-CdA (0.1 microgram/ml) at concentrations that inhibit by 80-90% the PHA-induced proliferative responses of lymphocytes did not affect IL-2 mRNA accumulation. Hybridization with a bcl-2-specific probe showed that the activation-induced accumulation and kinetics of bcl-2 mRNA were not changed in the presence of a wide range of concentrations of either GST or 2-CdA. Similarly, the mRNA accumulation of the "house-keeping" control gene beta-action remained unchanged by both agents. These findings indicate that biosynthesis of bcl-2 is not specifically affected by GST and CdA, suggesting that the immunomodulating effects of these agents, including their efficacy in suppressing chronic arthritis, are not related with a bcl-2-dependent mechanism.

Lack of clonal BCRA2 gene deletion on chromosome 13 in chronic lymphocytic leukaemia

Chromosome 13q deletion is among the most common cytogenetic abnormalities in chronic lymphocytic leukaemia (CLL). We investigated the 13q14.3 deletion in 44 CLL patients by Southern blotting following purification of clonal B CLL cells to >90%. Two sets of probes were used to investigate the site of clonal deletion, the D13S25 and D13S319 markers (at 13q14.3) and probes for exons 11 and 26-27 of the BRCA2 gene (at 13q12). Homozygous and heterozygous deletion at the 13q14.3 region was found in five and 17 patients, respectively. Despite the recent report of the BRCA2 gene involvement in >80% of CLL patients, we failed to detect a single case of homozygous or heterozygous deletion involving the 13q12 region. Our data support previous findings that the 13q14.3, and not the 13q12 region, is the major site of candidate tumour suppressor gene(s) in CLL.

Role of double-stranded RNA-activated protein kinase in human hematological malignancies

The double-stranded RNA (dsRNA)-activated protein kinase (PKR) is one of many genes induced by IFN. The PKR sequentially undergoes autophosphorylation and activation on binding to dsRNA. Previous studies have shown that PKR may be an important factor in the regulation of viral and cellular protein synthesis. Recent studies suggest that PKR may function as a tumor suppressor gene. The role of PKR in various human leukemic cells was therefore investigated. PKR mRNA levels by reverse transcription-PCR, protein expression by Western blot and FACScan analysis, and activity by phosphorylation status were studied. The expression of a known inhibitor of PKR, p58, was also investigated at mRNA and protein levels. A total of 24 samples from normal mononuclear cells (MNCs), 26 samples of acute lymphoblastic leukemia, 26 samples of acute myelogenous leukemia, 32 samples of chronic lymphocytic leukemia, and 5 samples of hairy cell leukemia was investigated. Mean mRNA levels were increased in acute lymphoblastic leukemia and acute myelogenous leukemia and decreased in chronic lymphocytic leukemia compared to normal MNCs. The mRNA levels in hairy cell leukemia were similar to those of normal MNCs. PKR protein was detectable in normal MNCs and leukemic cell extracts, and on FACScan analysis, more than 70% of cells stained positive for PKR. PKR activity was detectable in all samples investigated and was enhanced 4-23-fold in the presence of the synthetic dsRNA, poly(I) x poly(C). Protein expression of a known PKR inhibitor, p58, was barely detectable in normal MNCs and leukemic cells, with high expression in the HeLa cell line. These findings provide no evidence to support the hypothesis that PKR acts as a tumor suppressor in human leukemic cells.

Monocytes induce E-selectin gene expression in endothelial cells: role of CD11/CD18 and extracellular matrix proteins

E-selectin is an endothelium-specific inducible adhesion molecule which binds several inflammatory cell types, including neutrophils, monocytes, natural killer cells and a subset of memory T cells. E-selectin is important in the initial rolling interaction of these cells on inflamed endothelium. The transient kinetics of E-selectin induction in vitro contrast with in vivo observations of prolonged expression of this adhesion molecule in chronic inflammation. This raises the possibility that signals generated within inflammatory tissues are more complex than the agonists used to activate endothelial cells in vitro. We investigated whether adhesive interactions with extravasating monocytes are able to provide activating signals that can induce E-selectin expression on endothelium, and prolong the response to cytokine stimulation. We report that co-culture with monocytes led to transcriptional activation of the E-selectin gene in endothelial cells, and marked enhancement of the response to substimulatory concentrations of interleukin-1. In addition, the presence of monocytes resulted in prolonged up-regulation of E-selectin. Induction of E-selectin by monocytes was inhibited when cell contact between monocytes and endothelium was prevented (80 +/- 8% inhibition, p < 0.001, n = 4). Monoclonal antibody (mAb) against tumor necrosis factor (TNF) was able to abolish 57.2 +/- 9.7% of the response (p < 0.01, n = 4). The ability of adherent monocytes to induce sustained E-selectin expression in endothelial cells could not be reproduced either by supernatants harvested from monocytes cultured for 18 h, or by maximal concentrations of TNF. The induction of E-selectin in monocyte/endothelium co-cultures was inhibited by mAb to CD11b, but not by those directed against VLA-4 or L-selectin. Extracellular matrix molecules may also play a role in adhesion-dependent cellular activation, as inclusion of soluble collagen type I led to significant reduction in E-selectin expression in monocyte/endothelium co-cultures. We conclude that adhesive interactions between monocytes and endothelial cells provide a source of signals which influence the activation state of the endothelium, and consequently, the continued influx of inflammatory cells.

Regulation of bcl-2 and fas expression in primary activation of human peripheral lymphocytes is not sensitive to dexamethasone or cyclosporin-A

The regulation of bcl-2 and fas (Apo-1/CD95) gene product expression plays a significant role in lymphocytes proliferation, survival, and apoptosis. Dexamethasone (Dex) and the immunosuppressive agent cyclosporin-A (CsA) inhibit primary activation of lymphocytes by distinct, though overlapping mechanisms that trigger undefined signals and can induce or prevent apoptosis in lymphoid cells in vitro. Here we demonstrate that Dex and CsA, at concentrations that markedly inhibit phytohemagglutinin (PHA)-induced proliferation of normal human peripheral blood lymphocytes, suppress the activation-dependent expression of interleukin 2 (IL-2) and the alpha-chain IL-2 receptor in a dose-dependent fashion without affecting the inducible accumulation and kinetics of either bcl-2 or fas mRNAs. Similar results were obtained when PHA-stimulated lymphocytes were cultured in the presence of the CsA analogue FK-506 or rapamycin. Moreover, the inducible maximal expression of either bcl-2 or fas protein levels on 48-h PHA-activated lymphocytes was not changed in the presence of either Dex or CsA. These findings show that the cell activation-induced biosynthesis of bcl-2 and fas proteins is not affected by immunosuppressive agents, suggesting that the expression of IL-2 and both bcl-2 and fas genes is regulated through independent mechanisms.

Factors that influence activated CD8+ T-cell apoptosis in patients with acute herpesvirus infections: loss of costimulatory molecules CD28, CD5 and CD6 but relative maintenance of Bax and Bcl-X expression

The expanded CD8+ T-lymphocyte population arising in response to viral infection controls the virus but could also prove damaging to the host unless safely removed at the end of the immune response. Apoptosis provides a mechanism whereby this can be achieved, as apoptotic cells are recognized and engulfed by macrophages. Peripheral blood CD8+ T lymphocytes from individuals with acute viral infections were highly susceptible to apoptosis after short-term culture in vitro. This spontaneous cell death could be prevented by interleukin-2 (IL-2) and was related to a decreased expression of Bcl-2 but not Bax or Bcl-XL, additional molecules that promote or prevent apoptosis, respectively, as well as an increase in CD95. After stimulation with anti-CD3 antibody, T cells from these patients also underwent an activation-induced cell death (AICD) that could not be prevented by IL-2. Interestingly, CD8+ T cells from this patient group expressed lower than normal levels of three costimulatory molecules, CD28, CD5 and CD6, suggesting that stimulation in the absence of a second signal is a possible mechanism for the defective reactivation of these cells. Thus multiple mechanisms, including loss of Bcl-2, increased CD95 and loss of costimulatory molecules, place constraints on the survival and reactivation of activated CD8+ T cells after viral infections. This enables immune activation to be controlled and cellular homeostasis to be re-established during resolution of viral diseases in vivo.

Interleukin-6 inhibits apoptosis and tumour necrosis factor induced proliferation of B-chronic lymphocytic leukaemia

There is now good evidence that tumour necrosis factor [TNF] stimulates DNA synthesis of B-chronic lymphocytic leukaemia (B-CLL) cells. The malignant clone produces TNF, and addition of exogenous TNF up-regulates the TNF mRNA in B-CLL cells. Interleukin-6 (rIL-6) may also be important in this growth loop. We studied the interaction of TNF and IL-6 in the regulation of DNA synthesis (3H-TdR uptake), cytokine release and cell survival in CLL cells in vitro. Addition of TNF (100 U/ml over 5 days) enhanced DNA synthesis from 718 +/- 284 (mean cpm +/- SE) to 2730 +/- 545 compared to cells cultured in medium alone (n = 16, p < 0.01). TNF-alpha induced DNA synthesis was inhibited in all cases studied by the addition of anti-TNF monoclonal antibody (5 micrograms/ml) to cell cultures. Spontaneous IL-6 protein release was enhanced in the presence of TNF (100 U/ml and 250 U/ml) by CLL cells at 48 hours of culture 143.6% and 172% (p < 0.05, n = 6). At 120 hours of culture, the increase was 323% and 412.5% (4 of 7 cases) of the control respectively. IL-6 (100 U/ml or greater) increased spontaneous DNA synthesis (3H-TdR uptake) but, in the presence of high concentrations of TNF-alpha, inhibited TNF induced DNA synthesis in a dose dependent manner. Cell survival was reduced in the presence of anti-IL-6 mAb, while IL-6 was able to protect CLL cells from spontaneous apoptosis. These results suggest that IL-6 in an autocrine manner may inhibit DNA synthesis but prolongs survival in CLL cells. Increased serum IL-6 levels were detected in 27 of 50 cases of CLL, the mean level being significantly higher in Rai Stage III and IV cases compared to Rai Stage O-II cases.

Downregulation of interleukin-2 and apha-chain interleukin-2 receptor biosynthesis by cisplatin in human peripheral lymphocytes

To further investigate the mechanisms by which the antineoplastic agent cisplatin interferes with immune function, we studied its effect on the biosynthesis of interleukin-2 (IL-2) and its alpha-chain receptor (IL-2Ralpha). Normal human peripheral blood lymphocytes (PBL) were activated in vitro with phytohemagglutinin (PHA), and anti-CD3 antibody in the presence of various concentrations of cisplatin. Purified T cells were also cultured with anti-CD3 antibody and costimulated by CD80 (B7-1, B7/BB1)-transfected P815 mastocytoma cells in the presence of cisplatin. Tritiated thymidine incorporation assays, an enzyme-linked immunosorbent assay for soluble IL-2Ralpha determination, and RNA dot-blot analysis and hybridization with IL-2- and IL-2Ralpha-specific probes were used. PHA-induced and anti-CD3 antibody-induced proliferation of PBL were significantly inhibited by cisplatin at concentrations attainable in vivo. This inhibition was not due to direct cell death as shown by the absence of trypan blue uptake in the presence of high concentrations of cisplatin. Therapeutic concentrations of cisplatin (1 microgram/ml) also inhibited the IL-2-dependent proliferation of purified T cells, mediated via the CD28-CD80 costimulatory pathway. In addition, the amount of soluble IL-2Ralpha released in the T cell culture supernatants was decreased by cisplatin in a dose-dependent fashion, suggesting that inhibition of cell proliferation was associated with a parallel decrease in IL-2Ralpha production. These effects correlated with a specific cisplatin-induced downregulation of both IL-2 and IL-2Ralpha messenger RNA accumulation in PHA-stimulated PBL that was dependent on the concentration of the drug. These findings suggest that the immunomodulatory effects of cisplatin may result in part from its capacity to directly downregulate the IL-2/IL-2R system in activated lymphocytes.

Human bone marrow stromal cells prevent apoptosis and support the survival of chronic lymphocytic leukaemia cells in vitro

Leukaemic cells from most cases of B-chronic lymphocytic leukaemia die rapidly by apoptosis in vitro unless they are cultured in the presence of interleukin-4 or interferon alpha or gamma. We now report prolonged survival of purified CLL cells cultured on bone marrow (BM) derived stromal cells in the absence of exogenous growth factors. In 10 cases of CLL examined 0-61% (mean 14.7%) of the cells were viable after 10 d culture in medium alone, whereas in the presence of BM stromal cells 10-102% (mean 47.0%) of cells were recovered alive (P < 0.005) in 7/10 cases of CLL, cells remained viable after 30 d of culture in BM stromal cells with cell recovery of 12-65%. These long-term cultured CLL cells were Epstein Barr virus negative, shown by the failure to detect the ENBA-2 and BZLF1 genes of EBV by PCR analysis. Identity between day 0 and day 30 CLL cells was demonstrated by sequence analysis of their clonal IgH CDR3 region. Adherence of CLL cells to BM stromal cell layers was critical for their protection from apoptosis. Separation of CLL cells from stroma by 0.45 micron culture filters resulted in loss of the protective effect of the stromal cells. Stromal cells were also able to protect CLL cells from hydrocortisone-induced apoptotic cell death. Our findings provide an in vitro system that can be used to analyse the growth requirements of CLL cells and their chemosensitivity in an in vitro environment that mimics the in vivo milieu.

A trinucleotide deletion together with a base duplication event at codon 439 in the human tyrosinase gene identifies a mutational hotspot

Molecular analysis of the human tyrosinase gene in two patients suffering from a temperature-sensitive form of albinism has identified a thymine triplet deletion at codon 439 which is accompanied by a duplication of the immediately preceding cytosine residue. This results in a two base pair frame shift leading to premature termination at codon 448, giving a truncated protein. Its relationship to other mutations in tyrosinase and the possible cause are discussed. The temperature-sensitive phenotype is due to the guanine to adenine mutation at codon 422, known to generate a temperature-sensitive enzyme. The CTTT at F439 in tyrosinase is also present at F508 in CFTR, the main mutation causing cystic fibrosis.

Expression and function of the FAS antigen in B chronic lymphocytic leukemia and hairy cell leukemia

The expression and function of the FAS antigen was analyzed in 21 patients with B chronic lymphocytic leukemia (CLL) and four with hairy cell leukemia (HCL) using a specific IgM monoclonal antibody and FACS analysis. The FAS antigen was expressed in a minority (5-41%, mean 15.6%) of the CLL cells in 10 of 21 CLL patients and this expression was not modified during spontaneous or hydrocortisone-induced apoptosis of CLL cells. In contrast, culture with gamma-interferon (gamma-IFN) upregulated the expression of FAS in all CLL patients, with 65-100% (mean 84.8%) of the cells being positive after 2 days in vitro culture. Culture with alpha-IFN induced FAS expression in 15 of 19 CLL patients tested, with 15-74% (mean 34%) of the cells being FAS+ after 2 days culture. IL-4 and IL-10, lymphokines that inhibit and promote CLL apoptosis respectively, did not modify the expression of FAS. These results from FACS analysis were consistent with FAS mRNA analysis of fresh and cultured CLL cells, using a semi-quantitative reverse transcriptase (RT)-PCR technique. Although IL-4 and IFNs prevent apoptotic cell death of CLL cells in vitro, the present results show that IFNs induce the expression of the apoptosis-inducing protein FAS. However, FAS+ CLL cells were not killed in the presence of anti-FAS monoclonal antibody (while the FAS+ Jurkat and four lymphoblastoid cell lines were killed). This resistance is not due to a mutated FAS protein, since only wild-type FAS cDNA was demonstrated in the leukemic cells of three CLL patients. In four HCL patients 34-53% (mean 44.5%) of the leukemic cells were FAS+ and they were also resistant to the anti-FAS mediated cytotoxicity. The combination of high bcl-2 protein levels and resistance to anti-FAS mediated cytotoxicity may contribute to the extended in vivo survival of CLL and HCL cells.

Serum soluble interleukin-2 receptors as an index of the biological activity of thyroid hormones in hyperthyroidism

In order to examine whether serum soluble Interleukin-2 Receptors (sIL-2R) could be used as a marker of the biological effects of the thyroid hormones, we measured the sIL-2R, sex hormone binding globulin and beta-2 microglobulin levels in thirty-three hyperthyroid patients (14 with Graves' disease, 17 with Toxic Nodular Goiter and 2 with toxic adenoma) before and during treatment with antithyroid drugs. We found that serum sIL-2R concentrations of the patients, at diagnosis, were significantly higher compared with normal controls (2424 +/- 1447 vs 459 +/- 184 U/ml). All hyperthyroid patients had sIL-2R levels > mean + 2SD of normal controls, with 28 of the 33 patients having sIL-2R concentrations higher than 1011 U/ml (mean + 3SD of normal controls). Only 15 patients had SHBG levels higher than 3SD above the mean for the normal controls and 28 had SHBG levels 2SD above the mean for the normal controls. Three of the 5 hyperthyroid patients with normal SHBG levels at presentation had abnormally high sIL-2R levels. In all patients sIL-2R levels decreased gradually during therapy down to normal levels when euthyroidism was achieved. A strong positive correlation was found between sIL-2R, SHBG and T3 and T4 concentrations. Serum B2-microglobulin (B2-m) levels were higher than the upper normal limit only in 9 patients, but a significant decrement was observed in all patients when euthyroidism was achieved. The above results indicate that serum sIL-2R levels could be a useful marker of the in vivo biological effects of the thyroid hormones on lymphocytes in hyperthyroid patients.

Effective treatment of disease-related anaemia in B-chronic lymphocytic leukaemia patients with recombinant human erythropoietin

Nine B-chronic lymphocytic leukaemia (B-CLL) patients suffering from anaemia, due to no obvious cause except their disease, were treated with recombinant human erythropoietin (r-HuEPO). The treatment protocol provided a closed label phase of 3 months duration, during which the patients received r-HuEPO or placebo in a ratio of 2:1, followed by an open label phase, also of 3 months duration, during which r-HuEPO was administered to all patients three times a week s.c. r-HuEPO was given a dose of 150 U/kg of body weight with an escalation of 50 U/kg up to a maximum of 300 U/kg three times a week. Complete response was achieved in 5/9 (55%) patients and partial response in 3/9 (33%). The response obtained was independent of the pretreatment serum EPO levels, the duration of anaemia, the concomitant administration of chemotherapy, the presence of splenomegaly, or the degree of bone marrow infiltration by lymphocytes. It appears that r-HuEPO is very effective in reversing the disease-related anaemia of B-CLL patients.

Iron chelators induce apoptosis in proliferating cells

The iron chelators 1,2-dimethyl-3-hydroxypyrid-4-one (L1) and desferrioxamine (DFO) were found to induce apoptosis of proliferating activated T-lymphocytes and of the promyelocytic cell line HL60, but not of resting peripheral blood lymphocytes or granulocytes. The induction of apoptosis was quantified by propidium iodide staining of apoptotic/dead cells and flow cytometry. In activated T-lymphocytes incubated with the chelators at equivalent iron-binding concentrations (300 microM L1 or 100 microM DFO) for 24 h, L1 caused a 54% increase in cell death and DFO a 57% increase. In HL60 cells L1 caused a 50% increase in cell death and DFO a 40% increase. DNA cytofluorometry of HL60 cells treated with either chelator showed an increase in the percentage of cells with hypodiploid DNA content. Presaturation of the chelators with ferric chloride abrogated these effects. L1 and DFO did not induce apoptosis in resting peripheral blood lymphocytes or granulocytes, even after 48 h of incubation.

The association of systemic lupus erythematosus and myasthenia gravis

Two women with the rare association of systemic lupus erythematosus (SLE) and myasthenia gravis (MG) are reported. The first patient developed SLE (arthritis, severe thymectomy for MG. The second patient developed SLE (oral ulcers, arthritis, serositis, leukopenia, high titres of anti-DNA and anti-nuclear antibodies) 4 years prior to the clinical and serological onset of MG. Lymphocyte subsets and in vitro proliferative responses of peripheral blood mononuclear cells to mitogens were normal in both patients. A review of the literature revealed 26 additional patients with definite SLE coexisting with MG. Besides the theoretical interest of this association, the differential diagnosis of fatigue in patients with SLE should always include the possibility of MG.

Alpha-interferon (alpha-IFN) protects B-chronic lymphocytic leukaemia cells from apoptotic cell death in vitro

B-chronic lymphocytic leukaemia cells (CLL) are prone to apoptotic cell death when cultured in vitro. Apoptosis and loss of the bcl-2 protein is prevented in CLL cells cultured in the presence of interleukin-4. In this study we analysed the effects of alpha-IFN on the DNA fragmentation, bcl-2 protein levels and cell survival in purified B-cells from 16 CLL patients. Alpha-IFN (10(3) U/ml) reduced the degree of spontaneous DNA fragmentation of CLL cells after a 30 h culture period (from a mean of 22.2% in control cultures to 10.5%, P < 0.01). This inhibition was accompanied by preservation of bcl-2 protein and an increased survival of CLL cells compared to control cultures. In parallel, alpha-IFN inhibited hydrocortisone induced DNA fragmentation in CLL cells. The effects of alpha-IFN on DNA synthesis of CLL cells were variable (in two patients a decrease and in seven an increase in 3H-thymidine uptake) and did not correlate with the effect on DNA fragmentation. In conclusion, our data suggest that alpha-IFN, like IL-4 and gamma-IFN, inhibits apoptosis of CLL cells. These in vitro data indicate that the clinical responses of some CLL patients to alpha-IFN cannot be explained by a direct cytotoxic effect of alpha-IFN on circulating CLL cells. Alternatively, alpha-IFN may inhibit the proliferation of the small fraction of clonogenic CLL progenitors, or interfere with cellular interactions necessary for the survival and growth of CLL cells.

Influenza virus vaccine in B-cell chronic lymphocytic leukaemia patients

The clinical reaction and the immunological response to influenza virus vaccine were studied in 43 B-cell chronic lymphocytic leukaemia patients. The Vaxigrip vaccine was administered containing the antigens A/Ghizhou/54/89, A/Singapore/6/86, and B/Yamagata/16/88. The side-effects observed were minimal and well tolerated. Antibody production with titres > 1:20 on day 15 was observed at least for one antigen in 35 patients (81%). In 23 of them (63%) this response was retained on days 30 and 60. Patients with IgG levels (< 700 mg/dl) responded less well as compared to those having normal IgG levels (> 700 mg/dl).

Interleukin-4 inhibits apoptotic cell death and loss of the bcl-2 protein in B-chronic lymphocytic leukaemia cells in vitro

When monoclonal B cells from B-chronic lymphocytic leukaemia (B-CLL) patients are cultured in vitro, they die by apoptosis. Apoptotic cell death occurred in the B cells from 20/24 B-CLL patients after 26-30 h in in vitro culture, with 14.3-59.0% (mean 33.6%) of their DNA being fragmented in approximately 180 base pair multimers. After 8-10 d culture, 90-100% of the B-CLL cells were dead. Cell death and DNA fragmentation were inhibited in the presence of 0.5-5 ng/ml human recombinant interleukin-4 (IL-4) and viable monoclonal B cells could be maintained in culture up to 3 weeks. At 5 ng/ml, IL-4 reduced DNA fragmentation after a 26-30 h culture to 2.2-33.3% (mean 14.9%). IL-4 inhibited apoptosis without stimulating cell proliferation. In four patients the cells were resistant to apoptosis in vitro and they could be maintained for up to 4 weeks in culture medium alone. DNA fragmentation in all patients was increased in the presence of the RNA synthesis inhibitor actinomycin-D. Western blot analysis of cell lysates showed expression of the bcl-2 protein in all 11 B-CLL patients studied. However, during culture, bcl-2 protein levels were preserved only in patients resistant to apoptosis and were reduced in those susceptible to apoptosis. Reduction of bcl-2 protein levels was inhibited in cells cultured in the presence of IL-4. These data offer an explanation for the difference between the long life in vivo and rapid death in vitro of B-CLL cells and indicate that IL-4 may participate in the extended survival of these non-dividing cells in vivo.

High levels of serum soluble interleukin-2 receptors in hyperthyroid patients: correlation with serum thyroid hormones and independence from the etiology of the hyperthyroidism

The serum levels of soluble interleukin-2 receptors (s-IL-2R) and soluble CD8 antigens (s-CD8) were measured in 33 patients with Graves' disease (GD), 29 with toxic nodular goiter (TNG), 6 with toxic adenoma (TA), and 12 with hypothyroidism, as well as in 11 patients with infectious mononucleosis (known to have high s-IL-2R and s-CD8 levels) and 34 normal controls. Serum levels of T3 and T4, both total and free, and of TSH were simultaneously determined. s-IL-2R levels were significantly higher in all patients with hyperthyroidism (mean +/- SD, 3276 +/- 1273 U/mL for GD, 4183 +/- 1832 for TNG, and 1671 +/- 648 for TA) compared to normal control values (P less than 0.001 for GD and TNG and P less than 0.01 for TA), while in the euthyroid state they were within the normal range (535 +/- 240 U/mL). Hypothyroid patients had significantly lower s-IL-2R levels compared to normal controls (P less than 0.05). A positive correlation (P less than 0.001) between serum s-IL-2R levels and total/free T3-T4 levels was found in these groups of patients, while no correlation between s-CD8 levels and s-IL-2R/T3/T4 was found. These findings suggest an association between hyperthyroxinaemia and activation of human lymphocytes in vivo.

Effects of various metals on DNA synthesis and lymphokines production by human peripheral blood lymphocytes in vitro

1. The presence of Cd2+, Ni2+, Cu2+, Mn2+ and Co2+ (10(-4)-10(-6) M) caused a dose-dependent inhibition of DNA synthesis in phytohemagglutinin (PHA) stimulated peripheral blood mononuclear cells (PBMC) from normal human donors. No inhibition of DNA synthesis was observed in the presence of Mg2+ and Al3+. 2. Spontaneous and PHA induced interleukin-1 (IL-1) was enhanced in the presence of Mn2+. 3. The release of interleukin-2 (IL-2) and soluble interleukin-2 receptors (sIL-2R) was decreased by Cd2+, Cu2+ and Mn2+. 4. Spontaneous tumor necrosis factor-alpha (TNF-alpha) production was enhanced by Co2+ and Al3+, but decreased by Cd2+. 5. gamma-Interferon (gamma-IFN) production was decreased in the presence of Cd2+ and Cu2+ and increased in the presence of Al3+.