Factors influencing overall survival and GvHD development after allogeneic hematopoietic stem cell transplantation - single centre experience

BACKGROUNDS

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a substantial therapeutic procedure for the treatment of a wide spectrum of severe diseases. Despite advancements in treatment and supportive care, alloHSCT still carries a considerable mortality risk, primarily caused by graft-versus-host disease (GvHD). Our retrospective analysis aimed to identify the factors influencing overall survival and GvHD development in HLA-identical sibling alloHSCT. We have analyzed patients' and donors' age, AB0 compatibility, recipient-donor gender match, stem cell source, time from the diagnosis to alloHSCT, conditioning regimen type, GvHD prophylaxis, and relapse.

PATIENTS AND METHODS

Our study included 96 patients (54 male, 42 female) who underwent HLA-identical sibling alloHSCT. The median follow-up was 64.5 months (range 1-218 months), and the median age of both recipients and donors was 34 years. Malignant hematological diseases were the most common indications for alloHSCT.

RESULTS

GvHD and its complications accounted for the highest number of deaths (N = 24; 46.2%), followed by relapse (N = 18; 34.6%). Acute GvHD developed in 30 patients (31.3%), while chronic GvHD occurred in 25 patients (26.0%), resulting in a total of 45 patients (46.9%) experiencing GvHD. Male recipients with female donors had significantly worse overall survival compared to other patients (P = 0.01; HR = 2.33). Overall survival was better in patients transplanted within 1 year from the diagnosis compared to those transplanted after 1 year (P = 0.03; HR = 1.93). No factor reached statistical significance regarding the impact on acute GvHD, chronic GvHD, or overall GvHD.

CONCLUSION

We confirmed that sex mismatch, specifically in the case of a female donor and a male recipient, significantly negatively affects overall survival after alloHSCT. Additionally, overall survival is significantly shorter when the interval between the diagnosis and alloHSCT exceeds one year.

Influence of different spectra of NOTCH3 variants on the clinical phenotype of CADASIL - experience from Slovakia

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary vascular disorder causing ischaemic attacks and strokes in middle-aged adults. Though the clinical spectrum includes some typical symptoms, recognition of the disease, especially at an earlier stage, is very difficult because of the highly variable manifestation and incomplete clinical picture. Characteristic brain MRI findings and the presence of pathogenic variants in the NOTCH3 gene are fundamental for CADASIL diagnosis. In this paper, we provide the first comprehensive report on CADASIL patients from Slovakia. Altogether, we identified 23 different pathogenic variants in 35 unrelated families. In our cohort of patients with clinical suspicion of CADASIL, we found a causal genetic defect and confirmed the diagnosis in 10.2% of cases. We present the case reports with up-to-date unpublished NOTCH3 variants and describe their phenotype-genotype correlation: p.(Cys65Phe), p.(Pro86Leu/Ser502Phe), p.(Arg156*), p.(Cys408Arg), p.(Tyr423Cys), p.(Asp1720His), and p.(Asp1893Thrfs*13). The most frequently described location for pathogenic variants was in exon 4, whereas the most common single variant was p.Arg1076Cys in exon 20. Based on the results of our study, we propose a re-evaluation of the criteria for the selection of patients suitable for NOTCH3 gene analysis. We hereby state that the currently used protocol of a high score requirement is not ideal for assessing molecular analysis, and it will be desirable to be less strict in criteria for genetic testing.

Diagnostic Tools of Waldenströms Macroglobulinemia - Best Possibilities for Non-invasive and Long-term Disease Monitoring

Waldenströms macroglobulinemia (WM) is a B-cell malignancy characterized by high level of monoclonal immunoglobulin M (IgM) paraprotein in blood serum and associated with the bone marrow infiltration by malignant cells with lymphoplasmacytic differentiation. WM remains incurable advances in therapy. Most of WM cases are associated with a somatic point mutation L265P in MYD88. Significantly higher risk of progression from the IgM monoclonal gammopathy of undetermined significance (IgM MGUS) to WM for patients with mutated MYD88 gene suggests that this mutation is an early oncogenic event and plays a central role in development of malignant clones. The second, most prevalent mutation in WM is found in the CXCR4 gene and is often associated with drug resistance and aggressive disease presentation. Therefore, detection of these mutations (MYD88L265P and CXCR4S338X) could be useful diagnostic and prognostic tool for the patients with WM. While detection of these mutations in bone marrow sample is common, the aim of our study was to compare sensitivity of detection of mutation from different cell fraction from peripheral blood and bone marrow. The results show possibility to describe MYD88 and CXCR4 mutation status even from peripheral blood sample (sensitivity for MYD88L265P was 100%, for CXCR4S338X 91%), which significantly facilitate material collection. Moreover, comparable detection sensitivity of these mutations in bone marrow and peripheral blood samples examined before and during the therapy offers a promising tool for more routine diagnostic and monitoring of disease progression.Key words: Waldenström macroglobulinemia - hematology - neoplasms - lymphoma - mutation - MYD88 - CXCR4.

SETD2 loss-of-function promotes renal cancer branched evolution through replication stress and impaired DNA repair

Defining mechanisms that generate intratumour heterogeneity and branched evolution may inspire novel therapeutic approaches to limit tumour diversity and adaptation. SETD2 (Su(var), Enhancer of zeste, Trithorax-domain containing 2) trimethylates histone-3 lysine-36 (H3K36me3) at sites of active transcription and is mutated in diverse tumour types, including clear cell renal carcinomas (ccRCCs). Distinct SETD2 mutations have been identified in spatially separated regions in ccRCC, indicative of intratumour heterogeneity. In this study, we have addressed the consequences of SETD2 loss-of-function through an integrated bioinformatics and functional genomics approach. We find that bi-allelic SETD2 aberrations are not associated with microsatellite instability in ccRCC. SETD2 depletion in ccRCC cells revealed aberrant and reduced nucleosome compaction and chromatin association of the key replication proteins minichromosome maintenance complex component (MCM7) and DNA polymerase δ hindering replication fork progression, and failure to load lens epithelium-derived growth factor and the Rad51 homologous recombination repair factor at DNA breaks. Consistent with these data, we observe chromosomal breakpoint locations are biased away from H3K36me3 sites in SETD2 wild-type ccRCCs relative to tumours with bi-allelic SETD2 aberrations and that H3K36me3-negative ccRCCs display elevated DNA damage in vivo. These data suggest a role for SETD2 in maintaining genome integrity through nucleosome stabilization, suppression of replication stress and the coordination of DNA repair.

[Pomalidomide in the treatment of relapsed and refractory multiple myeloma]

Despite improvements in multiple myeloma therapy, the vast majority of patients continue to suffer relapses. Unfortunately, many patients event. develop disease that is refractory to lenalidomide and bortezomib and have few treatment options. Pomalidomide is a potent second-generation immunomodulatory agent with direct antiproliferative, pro-apoptotic, and antiangiogenic effects, as well as modulatory effects on bone resorption and on the immune system. Pomalidomide exhibited more potent anti-myeloma activity compared with thalidomide and lenalidomide. The optimal starting dose of pomalidomide is 4 mg given orally on days 1-21 of each 28-day cycle and combination with dexamethasone produces synergistic effects. In clinical trials, pomalidomide plus low-dose dexamethasone has shown better responses, progression-free and overall survival than high-dose dexamethasone or pomalidomide alone. Pomalidomide has limited cross-resistance with lenalidomide, and the overall response rates of pomalidomide in lenalidomide/bortezomib dual-refractory patients ranged from 26 to 31%. The most common grade 3 or 4 adverse events are hematologic, consisting of neutropenia, thrombocytopenia and anemia. Pomalidomide was approved by the FDA and the EMA in patients with multiple myeloma who have received at least two prior therapies including lenalidomide and bortezomib and have demonstrated disease progression on their last therapy. We review pomalidomide mechanism of action, clinical trials in relapsed and refractory patients, and novel pomalidomide-based combinations.

[Lenalidomide maintenance therapy in patients with multiple myeloma]

Maintenance therapy was recently defined as any treatment administered after the completion of induction therapy in patients whose disease is either responsive or nonprogressive at the time, with the goal of prolonging survival. Several studies have evaluated the use of novel agents as part of posttransplantation maintenance to improve progression free survival and overall survival. As shown by recent clinical trials, thalidomide and bortezomib are more indicated as consolidation agents, increasing the response rates. In contrast, lenalidomide showed a low toxicity profile and a benefit from prolonged treatment, making the drug one of the best choices for maintenance treatment. The role of lenalidomide in the maintenance therapy was evaluated in three randomized clinical trials. Lenalidomide was associated with a significantly increased progression free survival and in one study with a significant survival benefit. An unexpected finding from these trials was a modest increase in the incidence of secondary cancers. Whether lenalidomide maintenance should be routinely offered to patients is controversial among experts. For now, lenalidomide maintenance should be considered standard for patients not achieving a complete remission after stem cell transplantation, and for highrisk patients. For patients with low risk disease, the risk/ benefits of lenalidomide maintenance versus watchful waiting should be discussed until we have more data regarding survival benefits. Further analysis of lenalidomide maintenance therapy to determine the longterm risk of secondary malignancies and longer followup to assess the impact on overall survival is required.

[The late effects in patients treated with allogeneic hematopoietic stem cell transplantation]

BACKGROUNDS

Allogeneic hematopoietic stem cell transplantation (HSCT) has become a curative treatment option for a variety of malignant and non-malignant hematological disorders. The number of long-term survivors after HSCT is continuously increasing and quality of their life represents a multidisciplinary concern. The aim of this study was to evaluate the prevalence of the late effects in long-term allogeneic HSCT survivors.

PATIENTS AND METHODS

The study included 45 patients aged 12-63 years who survived at least two years after allogeneic HSCT for a hematological disorder. Twelve (26.7%) patients received an irradiation-based conditioning regimen. Median follow-up was 6 years (range 2-18 years).

RESULTS

Toxicity varied from subclinical to life-threatening. The prevalence of at least one late toxic effect was 88.9%. Endocrine and metabolic complications included thyroid abnormalities in 12 (26.7%) patients, bone and joints complications in 13 (28.8%) and metabolic syndrome in 13 (28.8%). Ocular complications were diagnosed in 20 (44.4%), cardiovascular abnormalities in 15 (33.3%), pulmonary dysfunction in 6 (13.3%) and secondary malignancies in 3 (6.67%) survivors. The number of complications per patient increased with time from HSCT. Chronic graft-versus-host disease was the most significant risk factor associated with ocular, pulmonary and osteoarticular complications.

CONCLUSION

Late toxicity of allogeneic HSCT in patients surviving for more than 2 years after this procedure may facilitate conduct of longer follow-up studies and an implementation of interventions to prevent late effects among survivors of serious hematological diseases

[Transfusion-induced immunomodulation and infectious complications]

Transfusions are not without risk. One of the side effects of transfusions is the development of transfusion-induced immunomodulation (TRIM)--primarily immunosuppression, but also a strong proinflammatory effect. This may be the cause of acute lung injury (TRALI), multiorgan failure (MOF), transfusion related acute-graft-versus-host-disease (TR AGvHD), as well as of the development of secondary nosocomial infections, mostly pulmonary infections, sepsis and wound infections, and also of elevated number of tumour relapses in oncological patients. The causes of TRIM development are the induction of microchimerism, different cells and also soluble factors--complement components, such as C3a, soluble HLA-I and HLA-II molecules (HLA--human leukocyte antigen), soluble Fas ligand (sFasL), and others. The immunosuppressive potential of blood products grows with the time of their storage and becomes highest in non-leukoreduced blood products stored for a long time. In view of possible adverse effects of a transfusion, the expected benefit should be balanced against possible risks.

A significance of additional chromosomal aberrations and other variables on post transplantation outcome of patients with CML

Chronic myeloic leukemia (CML) is a malignant disease of hematopoietic stem cell characterized by the bcr/abl gene rearrangement. Allogeneic transplantation of stem cells (SCT) is a routinely used treatment method of patients with this diagnosis and remains the only curative mode of treatment. From January 1990 to December 2002, 78 patients with CML underwent allogeneic transplantation and were examined at the Department of Genetics in the National Cancer Institute in Bratislava. Using conventional cytogenetic and FISH 6 patients (7.7%) showed additional chromosomal changes before SCT. These patients had statistically worse post transplantation prognosis compared to the patients without additional changes before SCT (mean survival in month+/-standard error (58.08 (+/-6.70) vs. 5.17 (+/-0.98), p-value=0.001), patient mortality (67% vs. 31%)). In addition five other variables were evaluated for transplant outcome, namely, patient's age at the time of transplantation, sibling or non-sibling donor, higher than 1st chronic phase CML, time from diagnosis to transplantation and sex of donor and recipient. Only the comparison of HLA-identical sibling transplantation to unrelated donor transplantation was statistically significant (mean survival in month- 56.6 (+/-7.2) vs. 13 (+/-0.0), patient mortality 31% vs. 67%).

[Bone changes in multiple myeloma--current etiopathogenic, diagnostic and therapeutic aspects]

Myelomatous bone disease affects about 90% patients with multiple myeloma and solitary myeloma as well. In initial stage it is manifested as osteopenia with osteoporosis or osteolytic foci, pathologic fractures followed by neurologic complications. Ethiopathogenitically a role is played by cytokine interactions with local chemokines produced by myeloma cells and activated stromal and hemopoietic cells (osteoblasts, monocytes, macrophages) resp. From the TNF-alpha family glycoprotein complexes are liberated (RANK-L), which support activation and proliferation or are inhibitory (osteoprotegerins). Similarly in the family TGF-beta several izotypes of antiinflammatory cytokines are known (the most important is TGF-beta 1 and the morphogenetic protein-2), which have a fibrotizing effect in bones, because the produced osteoid is insufficiently mineralized. The effect is a pathologic remodelation of the skeleton. In the diagnosis of multiple myeloma the immunological knowledge is used in the initial diagnosis (immunophenotypization, follow up of TNF-alpha, TGF-beta 1, IL-1, IL-6 etc). Important are also biochemistry values of increased osteoresorption (changes of calcium, parathormone, excretion of collagen fission products, osteocalcin, the bone alkaline phosphatase). In the following part the authors inform about favourable results of long-term treatment with bisphosphonates (Bonefos, Ibandronate) in combination with anti-tumor chemotherapy in 364 patients. During a 15 years observation period median survival of 94 months with a 35% probability of 10 year survival was achieved with a significant decrease of bone complications in 58% compared to 14% in the placebo group.

[Richter's syndrome (bimorphologic malignant lymphoma)]

Two distinct morphological types of malignant lymphoma in the same patient occur mostly due to transformation of a low grade lymphoma (CLL) into a large--cell non-Hodgkin lymphoma (high-grade lymphoma). Later reports have brough evidence of a clonal relationship between CLL and supervening NHL. The Richter's syndrome was found to be more frequent in patients with CLL displaying either multiple chromosomal aberrations or monoclonal gammapaties. In the last two decades reports have evidenced the existence of two types of the Richter's syndrome: one, the "classical" as a terminal event in a long evolving CLL, the other "variant" as the first clinical manifestation of a previously unrecognized subclinical CLL. Aggressive chemotherapy of CLL play a role in transformation of CLL to Richter's syndrome.

Retrolective cohort study of an additive therapy with an oral enzyme preparation in patients with multiple myeloma

PURPOSE

To evaluate the impact of an additive therapy with an oral enzyme (OE) preparation given for more than 6 months additionally to standard combination chemotherapy (vincristine/melphalan/cyclophosphamide/prednisone (VMCP)- or methylprednisolone/ vincristine/CCNU/cyclophosphamide/melphalan (MOCCA)-regimen) in the primary treatment of patients with multiple myeloma stages I-III.

METHODS

A cohort of 265 patients with multiple myeloma stages I-III was consecutively treated at our institution in two parallel groups (control group (n = 99): chemotherapy +/-OE for less than 6 months; OE-group (n = 166): chemotherapy + OE for more than 6 months). The median follow-up time in the stages I, II, and III for the OE-group was 61, 37, and 46.5 months, respectively; for the control group the respective values were 33, 51.5, and 31.5 months. The primary endpoint of the study was disease-specific survival. Secondary endpoints were response to therapy, duration of first response and side effects. The chosen method for evaluation was the technique of a retrolective cohort analysis with a concurrent control group. Survival analysis was performed by the Kaplan-Meier method and multivariate analysis was done with the Cox proportional hazards model.

RESULTS

Significantly higher overall response rates and longer duration of remissions were observed in the OE-group. Primary responders showed a longer mean survival time than non-responders. Additive therapy with OE given for more than 6 months decreased the hazard of death for patients at all stages of disease by approximately 60%. Observation time was not long enough to estimate the median survival for patients at stages I and II; for stage III patients it was 47 months in the control group versus 83 months for the patients treated with OE (P = 0.0014) which means a 3-year gain of survival time. Significant prognostic factors for survival, in the Cox regression analysis, were stage of disease and therapy with OE. The OE-therapy was generally well tolerated (3.6% of patients with mild to moderate gastrointestinal symptoms).

CONCLUSION

OEs represent a promising new additive therapy in multiple myeloma which will be further evaluated in a randomized phase III trial in the USA.

Prognostic significance of genetic markers in chronic myelogenous leukemia patients after bone marrow transplantation

Chronic myelogenous leukemia (CML) is a malignant disease of hematopoietic stem cell with a biphasic or triphasic clinical course and most often, with a fatal outcome. Significant progress in improving outcome for patients with CML has been achieved over past years. This can be attributed to marked improvement in therapeutic protocols and increased use of bone marrow transplantation (BMT) which remains the most effective option for long-term disease control of patient with CML. The residual leukemic activity in patients after BMT remains a central clinical question. To effectively monitor minimal residual disease leukemic activity after BMT, molecular genetic techniques are currently utilized in conjunction with cytogenetic assays. Because the clinical significance of detection minimal residual disease in CML remains to be determined, we performed cytogenetic analysis and PCR amplification technique in 37 Ph+ CML patients. All patients received transplants for CML in Bratislava between years 1992 and 1999. Our results suggest that PCR positivity after transplant is of limited prognostic significance for particular individuals and can be used to identified groups of individuals at elevated risk of relapse.

[Autologous stem cell transplantation in a patient with juvenile chronic arthritis]

In the submitted case-history the authors describe autologous haematopoietic stem cell transplantation (ASCT) in a patient suffering from juvenile chronic arthritis (JCA). ASCT was indicated by rheumatologists and haematologists for refractory polyarticular JCA. Mobilization with cyclophosphamide and granulocyte-colony stimulating factor was effective in terms of CD34+ cell shift to peripheral blood and the good quality autograft reliably led to haematopoetic recovery after megachemotherapy. The peritransplant period was not complicated with life threatening events. Immunosuppressive effect of autotransplant has reduced signs of rheumatoid disease activity and enabled conventional drug dose reduction. Autotransplant of haematopoietic stem cells has a potential to reduce activity of juvenile chronic arthritis.

Allogeneic BMT for haematological disorders: single centre experience of University Hospital Bratislava

Data on 65 sibling bone marrow transplantations (BMT) for various hematological disorders are reported. 51 patients had leukemia, 8 severe aplastic anemia, 4 myelodysplastic syndrome, one suffered from non-Hodgkin lymphoma and one from myeloid metaplasia. All but two patients have engrafted. Overall, 43 (66%) of 65 patients were alive 0,03-7,2 years (median not reached) as of June 23, 1997. Median time of observation was 13 months. Outcome of standard risk patients was significantly better than that of high risk patients (p=0,006). Our data confirm, that sibling BMT is an effective treatment modality with acceptable toxicity for younger patients with an early stage of serious hematological disorders.

[Osteoporosis in multiple myeloma]

The problem of osteoporosis is world-wide in people above 50 years of age. As this period is also a risk period for the development of multiple myeloma or other malignant processes, comprehensive differential diagnosis of malignant and benign osteoporosis is essential. By retrospective analysis of a 12-year group of 270 patients treated by chemotherapy on account of multiple myeloma the authors selected a group of 151 patients treated in addition to chemotherapy and immunomodulating drugs (mixture of proteolytic enzymes-Wobe Mugos) for 2-3 years, also with biphosphonates. At the time ofdiagnosis osteoporosis was in 24.5% patients the only finding on bones. When biphosphonates (Bonefos, Ibandronate) and chemotherapy were administered during a three-year observation period the bone process was stable in 61.59%, osseous changes disappeared in 11.26% and progression of osteolysis was recorded in 27.15%. The objective of the work was to emphasize the importance of a correct diagnosis of osseous changes which can progress even in clinically asymptomatic myelomas.

[Fibronectin and the human spleen]

Fibronectins are glycoproteins with a function of molecular glue. The aim of the study is to encourage interest in processes in extracellular matrix of the spleen. Undigested cryostat or formol-paraffin sections and commercially available antibodies were used. We were mostly successful in extracellular localization of fibronectin in trabeculae, vessel walls and lamellae of circumferent reticulum of periarterial lymphatic sheaths and in the ring fibres of the sinuses. Changes in the amount of fibronectin occurred, for example, in circulation disturbances. In hereditary spherocytosis the ring fibres were reduced. Increase of fibronectin can suggest the development of fibrosis.

[Density of adhesive proteins after oral administration of proteolytic enzymes in multiple myeloma]

The authors present information on the presence of adhesive proteins on membranes of myeloma and precursor cells isolated from bone marrow and blood from a group of 33 patients examined by fluorescent flow cytometry. They also compare the density of integrins (CD29, CD49e, CD41, CD51 and CD61) and adhesive proteins from the group of "homing" receptors (CD44) and IgG "superfamily" (LFA-1, LFA-3, ICAM-1, N-CAM) and their changes after a single oral dose of a mixture of proteolytic enzymes (Wobe Mugos, Wobenzym, MUCOS Pharma, FRG). The authors observed a significant drop of CD29, CD54 (ICAM-1), CD58 (LFA-3) after Wobe Mugos, CD49, CD51, CD58 after Wobenzyme. The insignificant decline of density of CD44 on cells, as well as of the soluble receptor of CD44 after oral administration of proteolytic enzymes in serum, incl. the mentioned changes of integrins and other adhesive proteins, indicate the importance of enzyme preparations in the supporting treatment of malignant processes.

Amphotericin B lipid complex to treat invasive fungal infections in cancer patients: report of efficacy and safety in 20 patients

20 patients with proven or suspected fungal infections were treated with the amphotericin B lipid complex (ABLC) with a daily dose of 5 mg/kg for 1-25 days. 6 patients died during the therapy due to fungal infection (3) or underlying disease (3). One patient was not evaluable. 13 patients were cured and improved. ABLC was administered in patients with renal disease avoiding the use of conventional amphotericin B (AmB) because of nephrotoxicity or after failure with AmB. Except for hypokalemia persisting after AmB in 5 patients, no systemic adverse reaction appeared. ABLC is a promising, well-tolerated and effective drug for the therapy of fungal infections after the failure of a previous antifungal therapy or after toxic reactions due to AmB.

[Comparison of the effectiveness and tolerance of Aktiferrin, a ferrous sulfate capsule preparation and Tardyferon pills in patients with uncomplicated sideropenic anemia]

BACKGROUND

The most frequent complications of oral administration of medicinal iron are gastrointestinal complaints the incidence of which correlates with the iron content of the preparation. The objective of the present work was to compare the effectiveness and tolerance of two ferrous sulphate preparations, Aktiferrin capsules and Tardyferon dragées which differ as to the elemental iron content.

METHODS AND RESULTS

To two groups of patients with sideropenic anaemia selected at random (39 women and 1 men, age 14-61 years, median 28 years) Aktiferrin or Tardyferon was administered. Administration of the preparations which have a more than double different elemental iron content had a comparable effect on the investigated haematological parameters. In the group treated with Akiferrin no GIT intolerance was observed, in the group with Tardyferon it was observed in four patients.

CONCLUSIONS

Aktiferrin has a comparable therapeutic effect although it contains 2.5 times less elemental iron, as compared with Tardyferon.

[Long-term survival in multiple myeloma]

The authors present the results of 23-year protocol studies of survival with multiple myeloma, focused on problems of perspective long-term survival. Of 535 diagnosed patients between 1970 and 1990 the authors checked regularly and treated 475. In addition to 60 latent forms where treatment was administered only when clinical symptoms developed or after progression of laboratory signs, to all patients treatment was administered according to protocols (monotherapy-cyclophosphamide prednisone in 1970-1975 only to 30 patients, the remainder had combined treatment--COPP, VMCP, MOCCA); in the third stage of the disease MOCCA treatment is better. The median of survival of patients after VMCP treatment (in stage II) MOCCA (in stage III) is more than 90 months, 15% survive for more than 10 years. The authors emphasize the importance of combined intensive treatment of patients for the prognosis of survival. Long-term experience revealed that patients achieve an objective response in 85%, while the risk of leukaemic and cancerogenic complications is low (1.1%). The therapeutic effect and survival period are favourably affected by immunomodulation treatment (Interferon, proteolytic enzymes, thymus factor).

[The favorable effect of hydrolytic enzymes in the treatment of immunocytomas and plasmacytomas]

At present attention is focused on research of biomodulating influences on tumorous processes, in particular inhibition of metastatic spread of tumors. In the aetiopathogenesis an important part is played by immune complexes, interaction of cytokines. The authors tested the supporting effect of hydrolytic enzymes in plasmocytoma and immunocytoma. The enzymes were administered along with cytostatic preparations according to the MOCCA pattern. They recorded a more rapid onset and longer persistence of remissions, a marked decline of total proteins, paraproteins, beta-2-microglobulin. Complications associated with paraprotein (hyperviscosity syndrome, nephrotic syndrome, peripheral angiopathy) improved. A combination of chemotherapy and enzymatic treatment proved effective and suitable, in particular for patients with interferon intolerance.

[Erythrocyte kinetics in myelodysplastic syndromes]

The authors made radioisotope examinations of the erythrokinetics in 21 patients with primary myelodysplastic syndrome: refractory anaemia and sideroblastic anaemia. He investigated the importance of changes of several conventional erythrokinetic parameters as well as the turnover of transferrin molecules which is an indicator of erythropoietic activity independent on sideraemia. The author presents ferrokinetic and erythrokinetic findings associated with myelodysplastic syndrome, as described in the literature. Sideroblastic anaemia produces a typical picture during examination of the erythrokinetics, quite different from other sub-types of the disease in refractory anaemia the changes of parameters are very variable.

[Possibilities of finding identical HLA donor-recipient pairs for bone marrow transplantation]

With the aim to detect genotypically identical donors for patients suffering from some type of leukemia or aplastic anemia, HLA antigens and MLC reactivity were determined in 72 families, having together 209 children. HLA identical, MLC negative sibling donors were found for 31 patients, i.e. 43%. Compared to the healthy population, no significant differences were found in the frequency of HLA antigens and haplotypes in 58 leukemic patients. Two recombinations were recorded, one between the loci HLA-A and HLA-B, and the other one between HLA-B and HLA-D/DR. Only 9 persons (2.5%) homozygous for HLA-D antigens were found in the whole series of 353 subjects investigated.