Bortezomib retreatment is effective in relapsed multiple myeloma patients - real-life clinical practice data.

Nowadays, bortezomib, a proteasome inhibitor, is widely used in treatment of newly diagnosed or relapsed multiple myeloma. The aim of this study was to analyze efficiency of bortezomib retreatment in patients with relapsed or refractory multiple myeloma. From 2004 to 2016, 283 patients were retrospectively evaluated at all hematological centers in the Czech Republic. Bortezomib was administered at the standard dosing and in combined therapy with corticosteroids, chemotherapy or thalidomide. Before bortezomib retreatment, 61% of patients received previous lenalidomide treatment, 40.6% autologous transplantation, and median number of prior lines of therapy was three. In total, 21% of patients were refractory to the first bortezomib treatment. In bortezomib retreatment, overall response rate was 34.5%, median progression-free survival was 7.8 months (95% CI: 6.7-8.9), median duration of response was 10.5 months (95% CI: 8.0-13.0) and median overall survival was 20.3 months (95% CI: 17.9-22.7). Grade 3-4 adverse events included thrombocytopenia, neutropenia, anemia and infection. Neuropathy grade 2 or higher occurred in 19.4% of patients. We conclude that bortezomib retreatment is an effective and safe therapeutic alternative for relapsed or refractory multiple myeloma patients.

Simplified novel prognostic score for real-life older adults with multiple myeloma-registry-based analysis.

The main goal was to find a simple prognostic to evaluate overall survival of patients older than 65 years of age with myeloma. Retrospective registry-based analysis from the Registry of Monoclonal Gammopathies was conducted. Patients over 65 years with symptomatic myeloma were included. The four major parameters with impact on survival were identified: male gender, age > 75, creatinine > 152 µmol/L, and ECOG performance status 2-4. The patients were scored as good (0 points), intermediate good (1 point), intermediate poor (2 points), poor (3-4 points). Patients (1410 MM) were included. Median OS (months) was 65.7 (95% CI 49.8-81.7) for good, 51.0 (44.1-57.8) for intermediate good, 32.2 (26.2-38.2) for intermediate poor, and 18.9 (15.1-22.7) for poor. The differences in OS were statistically significant (p < 0.0001). Good score was used as reference for hazard ratios, which for each other score were 1.43 (1.09-1.84) for intermediate good, 2.58 (2.00-3.33) for intermediate poor, and 3.88 (2.94-5.10) for poor. Time to progression showed medians (months) 20.5 (17.4-62.4) for good, 19.3 (17.0-21.7) for intermediate good, 19.6 (16.2-23.0) for intermediate poor, and 13.0 (10.8-15.2) for poor. The suggested scoring system provides readily available information about the prognosis of MM patients above 65 years.

Lenalidomide and dexamethasone in treatment of patients with relapsed and refractory multiple myeloma - analysis of data from the Czech Myeloma Group Registry of Monoclonal Gammopathies.

Lenalidomide (LEN) is an immunomodulator with clinical activity against myeloma cells. Based on the pivotal phase 3 trials MM-009 and MM010, the combination of lenalidomide and dexamethasone(DEX) was approved for patients with multiple myeloma who received at least one prior therapy. Here, we evaluated LEN/DEX therapy in unselected population and subsequently in selected sub-groups of patients with relapsed/refractory multiple myeloma followed in the Registry of Monoclonal Gammopathies of the Czech Myeloma Group. Altogether 858 patients were treated with LEN/DEX in the Czech Republic and Slovakia until end of 2017. The analyzed sub-groups were defined as patients with high risk cytogenetic aberrations and patients with relapsed and refractory MM. The overall response rate (ORR; partial remission or better response, PR) in the whole group of patients was 46.3% for all lines of therapy, 26.4% for high-risk group and 32.1% for relapsed and refractory group. Medians of overall survival (OS) in the same cohorts were as follows: 25.6, 15.7 and 18.5 months, progression free survival (PFS) was: 11.2, 6.4 and 9.0 months respectively. The most common adverse events were hematologic and infectious. In conclusion we found that our results correlated with those found in other studies in terms of response rates, survival measures, and also of treatment toxicity.

Histone deacetylase inhibitors in plasma cell leukemia treatment: effect of bone marrow microenvironment.

In the presented study we analysed the effect of histone deacetylase inhibitors (HDACi) suberoylanilide hydroxamic acid (SAHA) and valproic acid (VPA) on human plasma cell leukemia (PCL) cell line UHKT-944 in the presence of bone marrow microenvironment (BMM). For the analysis, the cells were cultured alone, with bone marrow stromal cells (BMSCs), with extracellular matrix (ECM) components or with interleukin-6, and treated with varied concentrations of SAHA and VPA for 24/48 hours. To study the effect of HDACi, we investigated cell proliferation, apoptosis, cell cycle and changes in selected signalling pathways. We found that both SAHA and VPA induced apoptosis, but had no effect on the cell cycle distribution of UHKT-944 cells. Investigation of the antiproliferative effect of SAHA and VPA revealed that BMSCs and high concentration of interleukin-6 had partial protective effect against SAHA or both inhibitors, respectively. No effect of ECM components on the efficiency of HDACi was observed. We further revealed that VPA down-regulated STAT3 phosphorylation while both inhibitors decreased Akt phosphorylation. In conclusion, VPA and SAHA might represent an additional therapeutic strategy in the PCL treatment. Protective effect of BMM should be taken into account when investigating prospective therapeutic agents against plasma cell disorders.

Asymptomatic and Treatment-requiring Multiple Myeloma - Data from the Czech Registry of Monoclonal Gammopathies.

BACKGROUND: Monoclonal gammopathy of undetermined significance (MGUS) and smouldering multiple myeloma (SMM) are premalignant stages of multiple myeloma (MM). MM is a malignancy of plasma cells, which is associated with a median overall survival of 5 to 7 years. MM accounts for approximately 10% of hematological malignancies. PATIENTS AND METHODS: Descriptive analysis of data from 19 Czech centres collected in the Registry of Monoclonal Gammopathies (RMG) was performed. RESULTS: Over the last 10 years of prospective collection of data, together with retrospectively recorded data on patients diagnosed before the registry establishment, data on 7,467 patients with either asymptomatic or symptomatic form of MM have been gathered. Validation criteria for the analysis were met by 2,506 MGUS patients, 400 SMM patients and 4,738 MM patients. The median duration of follow-up was 4.3 years in MGUS patients and 2.4 years in SMM patients. The overall risk of progression from MGUS to malignancy was 1.7% per year. The risk of progression from SMM to MM was highest in the 1st years after diagnosis: overall, this risk was 16.6% per year. The median duration of follow-up was 2.8 years in MM patients. The median overall survival from the diagnosis was 5.7 years. The median OS from treatment initiation/progression-free survival decreased from 60.5/21.0 months in the 1st line therapy to 34.3/12.4 months in the 2nd line therapy, 22.6/8.9 months in the 3rd line therapy and 13.8/5.8 months in the 4th or higher line therapies. Thanks to the availability of novel drugs for MM treatment in the Czech Republic, treatment strategies have changed dramatically over the last decade. CONCLUSION: RMG is a registry designated for the collection of data on diagnosis, treatment, treatment results and survival of patients with monoclonal gammopathies in the long-term follow-up. RMG is a valuable source of data from real clinical practice.Key words: registries - monoclonal gammopathy of undetermined significance - smouldering multiple myeloma - multiple myeloma - progression - treatment - survival.

[Anakinra treatment in Schnitzler syndrome -  results of the first retrospective multicenter study in six patients from the Czech Republic]. / Lécba anakinrou u Schnitzler syndromu -  výsledky první retrospektivní multicentrické studie sesti pacientu z Ceské republiky.

BACKGROUND: Schnitzler syndrome is a very rare, acquired, autoinflammatory disease of mostly adult onset with characteristic combination of chronic recurrent urticaria and monoclonal immunoglobulin M or G gammopathy predisposing the patients to malignant lymphoproliferation. In this work, we analyzed the results of bio-logical therapy with anakinra on a national level aiming to supply data for effective pharmaco-economic estimates, lay the grounds of nationwide patient registry, raise awareness among professional public and optimize provided health care. PATIENTS AND METHODS: The retrospective study (10/ 2006- 9/ 2013) included six males with definite Schnitzler syndrome verified by the new Strasbourg criteria. All patients were pretreated with antihistamines, nonsteroidal antiinflammatory drugs and glucocorticoids. Four patients underwent two or more treatment lines including intravenous bisphosphonates, 2- chlorodeoxyadenosine (cladribine), interferonα, PUVA photochemotherapy, cyclosporine A, thalidomide, bortezomib, chlorambucil, cyclophosphamide, colchicine and methotrexate. Anakinra monotherapy was initiated in standard dosing (100 mg subcutaneously daily). RESULTS: Complete and partial remissions were achieved in five (83%) and one patients (17%), respectively. Complete remission was characterized by urticaria and pain regression (within hours), normalization of inflammatory markers (with--in days) and bone metabolism improvement assessed by the markers of osteoblastic osteoformation and osteoclastic osteoresorption in one case (within weeks). With normalized inflammatory markers (including interleukin6 and interleukin18), arthralgia and sporadic exacerbations of urticaria and fevers persist in the patient in partial remission with proven Q703K polymorphism in NLRP3 gene. The median treatment followup was 30.5 months (37.2 ± 31.2 (n = 6)). The dosing interval was prolonged in one case of complete remission to 48 hours. No serious adverse reactions occurred during anakinra application. CONCLUSION: In Schnitzler syndrome, anakinra represents an effective, verified and safe medication with potentionally longterm administration not compromising its original efficacy and subjective tolerance. Anakinra, blocking autonomous inflammatory reaction of the organism via interleukin1 pathway, is a generally accepted first line treatment that should be made available in standard dosing for all Schnitzler patients.

[Multiple myeloma]. / Mnohocetný myelom.

Multiple myeloma is one of the most common hematological malignancies with increasing prevalence. Not until the introduction of 1 or 2 cycles of highdose therapy with the support of hematopoietic cells meant a certain progress in the prognosis of patients. The radical change in the therapy efficiency was not made possible until the so-called new or targeting drugs -  thalidomide, bortezomib and lenalidomide. The 2 latter preparations have particularly changed the approach to the disease itself from one of the least prognostically favourable hematological tumours to a longterm controllable malignancy with a potential to treat at least some of the patients. Currently, 3 ways of further progress towards more efficient treatment methods are under investigation: a) maintenance or consolidation treatment aimed at further intensification of therapeutic response, b) combination of targeting drugs and c) efficiency of the "second generation" targeting drugs.

Real world analysis of high-cut-off (HCO) hemodialysis with bortezomib-based backbone therapy in patients with multiple myeloma and acute kidney injury.

BACKGROUND: In patients with multiple myeloma (MM) free light chain-induced cast nephropathy is a serious complication associated with poor survival. High-cut-off (HCO) hemodialysis can reduce the amount of serum free light chains (sFLC), but data on its impact on clinical outcome is limited and contradictory. To gain further insights we collected real world data from two major myeloma and nephrology centers in Austria and the Czech Republic. METHODS: Sixty-one patients with MM and acute kidney injury, who were treated between 2011 and 2019 with HCO hemodialysis and bortezomib-based MM therapy, were analyzed. RESULTS: The median number of HCO hemodialysis sessions was 11 (range 1-42). Median glomerular filtration rate at diagnosis was 7 ± 4.2 ml/min/1.73m2. sFLC after the first HCO hemodialysis decreased by 66.5% and by 89.2% at day 18. At 3 and 6 months, 26 (42.6%) and 30 (49.2%) of patients became dialysis-independent. CONCLUSION: The widely used strategy combining HCO hemodialysis and bortezomib-based antimyeloma treatment is dissatisfactory for half of the patients undergoing it and clearly in need of improvement.

Distinguishing of primary mediastinal B-cell lymphoma and diffuse large B-cell lymphoma using real-time quantitative polymerase chain reaction.

Primary mediastinal B-cell lymphoma (PMBL) seems to be reliably distinguished from diffuse large B-cell lymphoma (DLBCL) with microarray technology. We measured expression of Fcer2, Pdl2 and Blk genes using real-time quantitative polymerase chain reaction (RTqPCR) on formalin fixed, paraffin embedded material (FFPE) and suggested a formula to discriminate PMBL from DLBCL. For 39/82 included patients the diagnosis of PMBL was expected clinico-pathologically. Diagnosis of 10/39 and 2/43 of clinically considered PMBLs and DLBCLs, respectively, was not genetically confirmed. Compared to confirmed PMBLs, unconfirmed ones showed clinical features similar to DLBCLs, e.g. spleen infiltration (p=0,028) and decreased invasiveness in pericardium (p=0,045). They tended to have more common infradiaphragmatic involvement, less often tumor sclerosis or fluidothorax. There were no immunohistochemical differences between genetically confirmed and unconfirmed PMBLs. New approach of distinguishing PMBL and DLBCL is presented. It is based on expression of three genes in routinely available FFPE material using RTqPCR.

Retrospective analysis of the results of high-dose chemotherapy with the support of autologous blood stem cells in patients with multiple myeloma. The experience of a single centre.

Despite new medical products introduced in multiple myeloma therapy, autologous stem cell transplant (ASCT) remains a standard procedure in younger patients with symptomatic disease. We analyzed a group of 190 patients who underwent ASCT at our clinic for multiple myeloma as primary therapy in years 1995-2008. The total number of transplants performed in this group was 291. 110 patients underwent one ASCT, 59 patients had double transplant, out of which 51 patients underwent tandem transplant, 21 patients underwent triple ASCT, out of which 15 patients were transplanted front-line throughout a clinical trial and 6 patients underwent follow-up transplants due to disease progression. The assessment of the best therapeutic effect of ASCT showed the total rates of patients with complete remission--22%, very good partial remission (VGPR)--8%, partial remission--63%, stabilized disease--6% and progression--1%. The transplant related mortality (TRM) was 4.1%. With the median follow-up of surviving patients 2.6 years, the median progression-free survival (PFS) and overall survival (OS) were 21 and 54 months, respectively; the likelihood of a 7-year overall survival was 28%. Comparing tandem versus single transplants, there was a significant increase in the median PFS (25.8 versus 20.8 months, respectively); however, there was no difference in overall survivals. The IVE mobilization regimen was found to be more efficacious for PBPC collection than high-dosed cyclophosphamide.

Methodology and results of real-world cost-effectiveness of carfilzomib in combination with lenalidomide and dexamethasone in relapsed multiple myeloma using registry data.

OBJECTIVE: To predict the real-world (RW) cost-effectiveness of carfilzomib in combination with lenalidomide and dexamethasone (KRd) versus lenalidomide and dexamethasone (Rd) in relapsed multiple myeloma (MM) patients after one to three prior therapies. METHODS: A partitioned survival model that included three health states (progression-free, progressed disease and death) was built. Progression-free survival (PFS), overall survival (OS) and time to discontinuation (TTD) data for the Rd arm were derived using the Registry of Monoclonal Gammopathies in the Czech Republic; the relative treatment effects of KRd versus Rd were estimated from the phase 3, randomised, ASPIRE trial, and were used to predict PFS, OS and TTD for KRd. The model was developed from the payer perspective and included drug costs, administration costs, monitoring costs, palliative care costs and adverse-event related costs collected from Czech sources. RESULTS: The base case incremental cost effectiveness ratio for KRd compared with Rd was €73,156 per quality-adjusted life year (QALY) gained. Patients on KRd incurred costs of €117,534 over their lifetime compared with €53,165 for patients on Rd. The QALYs gained were 2.63 and 1.75 for patients on KRd and Rd, respectively. CONCLUSIONS: Combining the strengths of randomised controlled trials and observational databases in cost-effectiveness models can generate policy-relevant results to allow well-informed decision-making. The current model showed that KRd is likely to be cost-effective versus Rd in the RW and, therefore, the reimbursement of KRd represents an efficient allocation of resources within the healthcare system.

Acute elevation of intraocular pressure in patient with hyperlipidemic myeloma.

PURPOSE: To introduce a rare case of patient with hyperlipidemic myeloma and ocular manifestation in form of masquerade syndrome with acute elevation of intraocular pressure (IOP) and hyperviscous retinopathy. RESULTS: 55-year-old man with newly diagnosed hyperlipidemic myeloma and hyperviscous syndrome was acutely referred to our glaucoma outpatient clinic due to problems with his left eye: sudden pain, blurred vision, redness of the eye and IOP of 44 mm Hg. We excluded attack of angle closure glaucoma and found presence of whitish material in the anterior chamber and blood obstructing the iridocorneal angle. Glaucoma therapy was initiated and lavage of the anterior chamber of the left eye with sampling of the aqueous humour for biochemical and cytological examination was performed. Identification of trace amount of cryoprotein in the samples of humour proved diagnosis of masquerade syndrome. Finding of the hyperviscous retinopathy and nonperfusion of wide peripheral areas of retina in both eyes was indicated to laser coagulation of these areas. The patient underwent in the meantime three times plasmapheresis, four cycles of biological therapy and autologous stem cell transplantation reaching complete remission of the myeloma. Local and systemic therapy led to significant clinical finding improvement on the anterior segment and fundus of both eyes. CONCLUSIONS: Masquerade syndrome can be complicated by acute elevation of IOP. Diagnostic lavage of the anterior chamber, local therapy, systemic therapy and close interdisciplinary cooperation contributed to right diagnosis, IOP normalisation, ocular and general condition improvement.

[Lenalidomid (Revlimid) in the treatment of multiple myeloma--first experience in the Czech Republic]. / Lenalidomid (Revlimid) v lécbe mnohocetného myelomu-- první zkusenosti v Ceské republice.

The prognosis of multiple myeloma (MM) has substantially improved during last decades due to new, so-called targeted drugs--proteasome inhibitor bortezomib and immunomodulatory drugs (ImiDs), thalidomide and lenalidomide. They could be used in various combinations and/or sequentially thanks to different mechanism of action and toxicity. Both bortezomib and thalidomide are widely used in Czech republic, however, lenalidomide was approved for the treatment of MM (and MDS) at the very latest and its usage is limited due to high costs, as well. According to the results of clinical trials lenalidomide is effective in myeloma refractory to various therapy including other new drugs. First time in the Czech republic the combination of lenalidomide and dexamethasone was given in our center to 2 patients with relapsed myeloma as 7th and 10th line of therapy. Acceptable results of treatment with improved clinical status in the first patient enabled to suspend his therapeutic plasmaferesis. Disease stabilization lasting three months was observed also in the second patient.

[The isolated form of cardiac amyloidosis in the form of beginning infiltrative cardiomyopathy without restrictive physiology]. / Izolovaná forma srdecní amyloidózy v podobe pocínající infiltrativní kardiomyopatie bez restriktivní fyziologie.

The authors describe an interesting case of isolated cardiac manifestation of AL-amyloidosis manifesting as an incipient infiltrative cardiomyopathy with heart failure symptoms due to moderate left ventricular diastolic dysfunction. Restrictive cardiomyopathy with severe diastolic dysfunction is considered as the characteristic manifestation of fully developed cardiac amyloidosis. However, the organ deposition of amyloid is progressive and left ventricular filling worsens continuously, starting with less advanced forms of diastolic dysfunction; the restrictive physiology is characteristic only for advanced phases of the disease. Therefore, the possibility of the incipient infiltrative cardiomyopathy due to the amyloidosis should be considered in patients with heart failure symptoms and echocardiographic findings of unexplained left ventricular hypertrophy with only mild or moderate diastolic dysfunction.

[Detection of free light chains--a new method of diagnostics of haematological diseases]. / Detekce volných lehkých retezcu ("free light chains")--nová metoda diagnostiky hematologickych onemocneí.

BACKGROUND: To diagnose monoclonal gamopathy, one of the most frequent haematological diseases, we use immunochemical assays, which are based on the detection of paraprotein in serum and/or urine. METHODS AND RESULTS: The most common laboratory assays we use are SPE (serum protein electrophoresis) and IFE (immunofixation electrophoresis). New method represents the detection of free light chain (FLC) in serum. In our study we compared those three methods (SPE, IFE and FLC) from the point of sensitivity of paraprotein detection. For FLC detection was used Freelite system analyzer (Immunotech Beckman Coulter). We examined 51 patients with diagnosis of multiple myeloma, nonHodgkin's lymphoma, primary amyloidosis and monoclonal gammopathy of undetermined significance. CONCLUSIONS: Detection of FLC is a valuable method which sometimes could specify diagnosis of MG and make the treatment more accurate.

Carfilzomib-lenalidomide-dexamethasone vs lenalidomide-dexamethasone in relapsed multiple myeloma by previous treatment.

Carfilzomib, a proteasome inhibitor, is approved as monotherapy and in combination with dexamethasone or lenalidomide-dexamethasone (Rd) for relapsed or refractory multiple myeloma. The approval of carfilzomib-lenalidomide-dexamethasone (KRd) was based on results from the randomized, phase 3 study ASPIRE (NCT01080391), which showed KRd significantly improved progression-free survival (PFS) vs Rd (median 26.3 vs 17.6 months; hazard ratio (HR)=0.690; P=0.0001). This subgroup analysis of ASPIRE evaluated KRd vs Rd by number of previous lines of therapy and previous exposure to bortezomib, thalidomide or lenalidomide. Treatment with KRd led to a 12-month improvement in median PFS vs Rd after first relapse (HR 0.713) and a 9-month improvement after ⩾2 previous lines of therapy (HR 0.720). Treatment with KRd led to an approximate 8-month improvement vs Rd in median PFS in bortezomib-exposed patients (HR 0.699), a 15-month improvement in thalidomide-exposed patients (HR 0.587) and a 5-month improvement in lenalidomide-exposed patients (HR 0.796). Objective response and complete response or better rates were higher with KRd vs Rd, irrespective of previous treatment. KRd had a favorable benefit-risk profile and should be considered an appropriate treatment option for patients with 1 or ⩾2 previous lines of therapy and those previously exposed to bortezomib, thalidomide or lenalidomide.

International Staging System required standardization of biochemical laboratory testing in multiple myeloma.

The standardization of biochemical measurement procedures in multiple myeloma is necessary for reliable prognostic stratification of patients in multicentric trials. The new prognostic index International Staging System for multiple myeloma uses only two laboratory markers, albumin and beta-2 microglobulin. Our study compared results of albumin, beta-2 microglobulin and monoclonal immunoglobulin measurements from six centers which provide treatment for multiple myeloma in the Czech Republic and attempted to standardize the analytic procedures. We have found that the measurement of albumin is well standardized and the results from all laboratories were comparable. The measurement of beta-2 microglobulin achieved comparability only after a partial unification of analytical methods. The determination of monoclonal immunoglobulin concentration provided comparable results for concentrations higher than 20 g/l with higher variability for lower values.

[Bortezomib (Velcade) in relapsed/refractory multiple myeloma--the first experience in the Czech Republic]. / Inhibitor proteazomu--bortezomib (Velcade)--v lécbe refrakterního mnohocetného myelomu První zkusenosti v Ceské republice.

BACKGROUND: Multiple myeloma is the second most prevalent and mostly fatal hematologic cancer. Further advances have been made in understanding the mechanisms involved in the myeloma pathogenesis and elucidation of critical signalling pathways as therapeutical targets. Proteasome inhibitors are the example of this new approach and bortezomib is the first agent in this class to enter clinical trials. METHODS AND RESULTS: In 6 hematological centers in Czech Republic 29 patients with refractory/relapsed myeloma had been treated with bortezomib (Velcade, Millennium Pharmaceuticals) in 2004. The initial dose 1.3 mg/m2 of Velcade was given, in 1 case the dose was adjusted due to pre-existing renal failure to 1 mg/m2. The response was achieved in 17 patients (59%). Four patients had complete, 11 partial and two minor responses. In 5 cases stabilization of disease was observed and 6 patients progressed during the therapy. CONCLUSIONS: Unfortunately, one patient died immediately after the start of therapy due to sepsis. The most common adverse events were thrombocytopenia, anaemia, neuropathy, gastrointestinal complication, renal failure and fatigue. Grade 4 adverse events occurred in 37.9% of patients (4x thrombocytopenia, 2x gastrointestinal, 2x renal failure, 1x sepsis, leucopenia, hepatopathy and anaemia, respectively). Peripheral neuropathic pain of grade 3 was reported in 4 cases, in one patient therapy had to be interrupted due to this complication. We confirmed promising results of phase II trials.

Antioxidant enzymes and lipid peroxidation in patients with multiple myeloma.

Reactive oxygen species and other free radicals are known to be the mediators of phenotypic and genotypic changes that lead from mutation to neoplasia. The imbalance in tumor cell antioxidant defense mechanism can influence also the sensitivity to cytoreductive therapy. In erythrocytes it can result to hemolysis which is one of the pathogenetic mechanisms of anemia in cancer patients. Parameters of lipid peroxidation (malondialdehyde-MDA) and antioxidant enzymes here represented by superoxide dismutase (SOD) and glutathione peroxidase (GPx) in multiple myeloma (MM) have been investigated. Nine patients of various clinical stages and activities of the disease were studied. Significantly higher concentrations of total MDA in plasma (1.20 +/- 0.24 mumol/l vs. 0.64 +/- 0.22 mumol/l, p < 0.0001) as well as in erythrocytes (2.72 +/- 0.81 mumol/l vs. 1.03 +/- 0.44 mumol/l, p < 0.0001) were found comparing to the control group. The levels of free MDA in plasma (0.31 +/- 0.09 mumol/l vs. 0.49 +/- 0.17 mumol/l, p < 0.05) and in erythrocytes (0.29 +/- 0.20 mumol/l vs. 0.59 +/- 0.22 mumol/l, p < 0.001) were decreased in myeloma patients. Significantly lower activities of GPx (19.17 +/- 4.07 U/g Hb vs. 23.26 +/- 3.61 U/g Hb, p < 0.05) and SOD (1882.46 +/- 181.73 U/g Hb vs. 2347.13 +/- 502.51 U/g Hb, p < 0.05) in erythrocytes were found. We did not observe evident relationship between the concentration of MDA or the activities of SOD and GPx and either the stage of the disease, or the level and the type of paraprotein. These results propose possible role of free radicals with reduced antioxidant activities of SOD and GPx in multiple myeloma.