[Detection of paraprotein in plasma cell tumors].

Paraprotein is a laboratory biomarker of plasma cell tumors and other lymphoproliferative diseases. Its determination is necessary for diagnosing, monitoring and assessment of therapy effectiveness. The lecture presents the main methods of qualitative and quantative analysis of monoclonal proteins: gel electrophoresis, capillary electrophoresis, immunofixation and nephelometry features, possibilities and limitations are reviewed. The main sources of errors and artifacts during these studies are considered. Also the difficulties in the diagnosis and interpretation of the results of serum and urine tests are highlighted.

Comparison of polymerase chain reaction and flow cytometry for measuring telomere length of human leukocytes.

Telomere length can be measured by polymerase chain reaction (PCR), allowing to obtain the absolute length of telomeres (ALT) in base pair, and by flow cytometry, which can only estimate the relative telomere length. The aim of the study was to compare the results of the two methods and to develop an accurate and reliable way of converting the relative telomere length to absolute. The peripheral blood from 21 donors was analyzed. Measurement of leukocyte telomere length by flow cytometry was carried out using a commercial Telomere PNA Kit / FITC (Dako, Denmark) with two CytoFLEX flow cytometers (Beckman Coulter, China) and BD FACSCanto II (Becton Dickinson, USA), obtaining the molecular equivalent of fluorescence (MEF). To measure telomere length by real-time PCR, calibrators with a known number of telomeric repeats were prepared. Two quantitative PCRs were carried out: one for telomeric repeats, the other for determining the number of genome-equivalents of DNA, three times for each sample, which made it possible to calculate ALT. A strong direct relationship was found between the MEF obtained with BD FACSCanto II and CytoFLEX (r = 0.97). Analysis of PCR and flow cytometry results showed a significant correlation between ALT and MEF. We calculated the regression equations of ALT and MEF for CytoFLEX - y = 0.0043x (r = 0.84) and for BD FACSCanto II - y = 0.0051x (r = 0.82). Correlation analysis showed a high comparability of telomere lengths measured by two methods. The obtained regression equations allow converting the results of flow cytometry into absolute values, allowing the comparison of the results of different research groups and the use of this method in clinical trials.

[Allogeneic hematopoietic stem cell transplantation in patients with multiple myeloma].

AIM: To analyze the effectiveness of allogeneic hematopoietic stem cell transplantation (allo-HSCT) from a related HLA-identical donor in patients with multiple myeloma (MM). MATERIALS AND METHODS: From 2013 to 2018, the study included 8 patients (6 men, 2 women) aged from 27 to 55 years (median 39 years) with MM who underwent allo-HSCT from a related HLA-identical donor (7 patients after auto-HSCT, in 1 case without previous auto-transplantation). All patients required 2 or more lines of induction therapy, while the achieved antitumor effect was unstable. Before allo-HSCT, complete and very good partial remission was determined in isolated cases, in 4 patients the response was regarded as partial remission, stabilization in 1 observation, progression in 1 patient. All patients underwent reduced intensity conditioning (fludarabine 30 mg/m2 6 days + busulfan 4 mg/kg 2 days). Immunosuppressive therapy included the administration of antithymocyte globulin and post-transplant cyclophosphamide. RESULTS: Severe acute GVHD (grade 34) was observed in 3 (37.5%) cases, which resulted in death in 1 case. A stable antitumor response was achieved in 5 (62.5%) patients, complete remission lasts for 2986 months after allo-HSCT. Specific therapy for these patients is not carried out. The 7-year progression-free survival rate was 75%, the 7-year overall survival rate was 84%, with a median follow-up of 65 months. The transplant-related mortality was 12.5%. CONCLUSION: Allo-HSCT is considered as an alternative method of therapy for young patients with aggressive MM. Allo-HSCT in MM in some cases leads to long-term immunological control of the tumor.

[Monoclonal gammopathy of renal significance: consensus of hematologists and nephrologists of Russia on the establishment of nosology, diagnostic approach and rationale for clone specific treatment].

Monoclonal gammopathy of renal significance (MGRS) is a new nosology in modern nephrology and oncohematology. MGRS is defined as kidney injury due to nephrotoxic monoclonal immunoglobulin produced by the B-cell line clone which does not reach the hematological criteria for specific treatment initiation. Monoclonal proteins pathological effects on kidney parenchyma result in irreversible decline of kidney function till the end stage renal disease that in line with the position of International Consensus of hematologists and nephrologists determinates critical necessity for clone specific treatment in patients with MGRS despite the absence of hematological indications for treatment initiation. Main challenge of MGRS in Russian Federation is an inaccessibility of an in-time diagnostic and appropriate treatment for the great majority of patients due to the following reasons: 1) limited knowledge about the MGRS among hematologists and nephrologists; 2) lack of necessary diagnostic resources in most health-care facilities; 3) lack of approved clinical recommendations and medical economic standards for treatment of this pathological entity. Consensus document comprises the opinion of experts leading nephrologists and hematologists of Russian Federation on the problem of MGRS including the incoherence in nosology classification, diagnostics approach and rationale for clone specific treatment. Consensus document is based on conclusions and agreements reached during the conference of leading nephrologists and hematologists of Russia which was held in the framework of symposia Plasma cell dyscrasias and lymphoproliferative diseases: modern approaches to therapy, 1516 of March 2019, Pavlov First Saint Petersburg State Medical University. The present Consensus is intended to define the principal practical steps to resolve the problem of MGRS in Russian Federation that are summarized as final clauses.

[Morphological and immunohistochemical predictors of renal response to therapy patients with myeloma cast nephropathy and dialysis-dependent acute kidney injury].

AIM: Reveal morphological and immunohistochemical predictors of reversibility of dialysis-dependent acute kidney injury (AKI) in patients with myeloma cast nephropathy (MCN) based on the study of kidney biopsy. MATERIALS AND METHODS: Renal pathological findings were studied in 36 patients with MCN and dialysis-dependent stage 3 AKI (AKIN, 2012). The study of biopsy samples was performed by a semi-quantitative and quantitative analysis using computer morphometry. The expression of E-cadherin, vimentin and-smooth muscle actin was determined immunohistochemically in the tubular cells and interstitium. Induction therapy for 26 patients was carried out to bortezomib-based programs; in 10 patients other schemes were used. A comparative analysis of morphological changes in nephrobiopathy depending on the renal response was performed in patients with achieved hematologic remission. RESULTS: Improved renal function was observed only in patients with hematologic response to therapy. There were no differences in the number of sclerotic glomeruli, protein casts, the area of inflammatory interstitial infiltration, and the degree of acute tubular damage in patients with and without renal response. In patients with renal response compared with patients without improving renal function, the area of interstitial fibrosis was less (24.9% and 45.9%, respectively;p=0.001), and the area of E-cadherin expression was larger (15.9% and 7.1%, respectively;p=0.006). Interstitial fibrosis of 40% or more and/or the area of expression of E-cadherin less than 10% of the area of tubulo-interstitium have an unfavorable prognostic value in achieving a renal response in MCN. CONCLUSION: If the interstitial fibrosis area is 40% or more and the expression area of E-cadherin is less than 10%, the probability of the absence of a renal response is 93.3% (OR=24.5) even when a hematological response to induction therapy is achieved. The number of protein casts, the prevalence of acute tubular damage and inflammatory interstitial infiltration have not prognostic value.

[Autologous haematopoietic stem cell transplantation in patients with multiple myeloma complicated by dialysis-dependent renal failure].

AIM: To assess the safety and efficacy of autologous haematopoietic stem cell transplantation (auto-HSCT) in multiple myeloma (MM) patients with dialysis-dependent renal failure. MATERIALS AND METHODS: During a period from May 2010 to December 2016 fourteen MM patients with dialysis-dependent renal failure aged 48 to 65 years underwent auto-HSCT. After the induction therapy complete response, very good partial response, partial response were documented in 64, 29, 7% of patients, respectively. In no case was a renal response achieved. Haematopoietic stem cell mobilization in most patients (13/14) was performed according to the scheme: G-CSF 10 g/kg. Melphalan in 3 dosages was used as pre-transplant conditioning: 100, 140 and 200 mg/m2; 13 patients underwent a single and in one case underwent a tandem auto-HSCT against the background of hemodialysis. Evaluation of the antitumor and renal response was assessed on the 100th day after auto-HSCT. Subsequently, against the background of programmed hemodialysis and in the setting of high-dosed melphalan (100200 mg/m2), 13 patients underwent a single and one patient underwent a tandem auto-HSCT. At +100 days after auto-HSCT, an antitumor response and renal response were assessed. RESULTS: The period of agranulocytosis after auto-HSCT was from 5 to 12 days (median 8,5) and was accompanied by infectious complications, cardiac and neurological dysfunctions. At +100 days after auto-HSCT, the complete response was confirmed in 71% patients and very good partial response was confirmed in 29% patients. The minimal renal response was registered in 2 patients (14%), hemodialysis was stopped. The transplant-related mortality was absent. After a median follow-up of 53 months 5-year progression-free survival was 59%, and overall survival was 93%. CONCLUSION: Carrying out auto-HSCT in patients with dialysis-dependent renal failure contributed to the achievement of a minimal renal response in 14% of cases, which allowed these patients to stop hemodialysis. Patients whose conditioning regimen was performed using melphalan at a dose of 200 mg/m2showed more frequent complications in the early post-transplant period compared to patients who received a lower dose of melphalan (100140 mg/m2). Auto-HSCT in MM patients with dialysis-dependent renal failure is a feasible and effective treatment method, which in some cases contributes to independence from hemodialysis.

[Bone disease as the first manifestation of systemic AL-amyloidosis].

Our case demonstrates severe bone disease in primary AL-amyloidosis without concomitant multiple myeloma. A 30-year-old man had spontaneous vertebral fracture Th8. A computed tomography scan suggested multiple foci of lesions in all the bones. In bone marrow and resected rib werent detected any tumor cells. After 15 years from the beginning of the disease, nephrotic syndrome developed. Based on the kidney biopsy, AL-amyloidosis was confirmed. Amyloid was also detected in the bowel and bone marrow. On the indirect signs (thickening of the interventricular septum 16 mm and increased NT-proBNP 2200 pg/ml), a cardial involvement was confirmed. In the bone marrow (from three sites) was found 2.85% clonal plasma cells with immunophenotype СD138+, СD38dim, СD19-, СD117+, СD81-, СD27-, СD56-. FISH method revealed polysomy 5,9,15 in 3% of the nuclei. Serum free light chain Kappa 575 mg/l (/44.9) was detected. Multiple foci of destruction with increased metabolic activity (SUVmax 3.6) were visualized on PET-CT, and an surgical intervention biopsy was performed from two foci. The number of plasma cells from the destruction foci was 2.5%, and massive amyloid deposition was detected. On CT scan foci of lesions differed from bone lesions at multiple myeloma. Bone fragments of point and linear type (button sequestration) were visualized in most of the destruction foci. The content of the lesion was low density. There was no extraossal spread from large zones of destruction. There was also spontaneous scarring of the some lesions (without therapy). Thus, the diagnosis of multiple myeloma was excluded on the basis based on x-ray signs, of the duration of osteodestructive syndrome (15 years), the absence of plasma infiltration in the bone marrow, including from foci of bone destruction by open biopsy. This observation proves the possibility of damage to the skeleton due to amyloid deposition and justifies the need to include AL-amyloidosis in the spectrum of differential diagnosis of diseases that occur with osteodestructive syndrome.

[Difficulties evaluating hematological response in patients with multiple myeloma and dialysis - dependent renal impairment].

AIM: to determine serum free light chains (FLC) level by patients with multiple myeloma (MM) and dialysis - dependent renal impairment in which the amount Bence Jones (BJ) protein in the urine met the criteria of hematological response. PATIENTS AND METHODS: This study included 13 MM with dialysis - dependent renal impairment patients (estimated glomerular filtration rate < 10 ml/min), whose urine BJ protein content was less than 200 mg/day after antimyeloma therapy (including 11 patients whose urine BJ protein content was less than 100 mg/day). RESULTS: The median serum concentration of monoclonal FLC was 608.7 (298-8380) mg/l. Thus, with trace amounts BJ protein in the urine serum content monoclonal FLC varied 28 times with the same degree of severity of renal failure. In patients with oliguria serum SLC content was significantly higher than in normal diuresis (1109 and 307 mg/L; p.

[PET/CT with 18F-fluorodeoxyglucose and 11C-methionine after autologous stem cell transplantation in multiple myeloma patients].

AIM: to compare the results of tumor visualization when using 18F-FDG and 11C-methionine PET/CT after auto-HSCT in MM patients. MATERIALS AND METHODS: A prospective study included 27 MM patients subjected to 18F-FDG and 11C-methionine PET/CT on day 100 after auto-HSCT. Obtained images were visually and semi - quantitatively analyzed. Focal areas of increased uptake for every radiopharmaceutical agent (hypermetabolic foci) not associated with its physiological distribution were registered. Maximum Standardized Uptake Values (SUVmax) in pathological foci were automatically calculated for every radiopharmaceutical agent separately. PET/CT findings were compared to antitumor response achieved after auto-HSCT according to International MM Working Group criteria. RESULTS: After auto-HSCT, the majority of patients (16/60%) achieved a complete response. Abnormal 18F-FDG uptake was registered in 37% (n=10) of patients, negative PET findings were obtained in 63% (n=17) of patients. 11C-methionine PET/CT revealed hypermetabolic foci in 67% (n=18) of patients, and there was no 11C-methionine uptake in 33% (n=9). Pathological foci of radiopharmaceutical agent uptake were 1.8 times more frequently revealed using PET/CT with 11C-methionine (p.

Minimal residual disease in multiple myeloma: Benefits of flow cytometry.

Over the last 20 years, the approaches to the treatment of multiple myeloma (MM) have changed considerably, which led to an increase in remission rate. Using new diagnostic methods has made it possible to assess the response to treatment more reliably and forecast disease recurrence: allele-specific polymerase chain reaction, new-generation sequencing and multicolor flow cytometry enable minimal residual disease (MRD) detection of with sensitivity of 10-5 to 10-6 . MRD assessment with flow cytometry using is a rapidly developing area of research. The goal of multicenter groups that use flow cytometry as a tool to detect MRD in patients with MM is achieving standardization and increasing sensitivity and specificity of this method. This article provides data about the methods used for MRD monitoring and describes the advances in the field of flow cytometry.

[Uromodulin gene polymorphisms in patients with cast nephropathy in multiple myeloma]. / Polimorfizmy gena uromodulina u bol'nykh kast-nefropatiei pri mnozhestvennoi mielome.

AIM: To investigate the nature of mutations in exons 4 and 5 of the uromodulin (UM) gene, including in the area encoding the domain of 8 cysteines (D8C), in patients with multiple myeloma (MM) with the secretion of monoclonal light chains (LC) in cast nephropathy (CN) and without kidney injury. SUBJECTS AND METHODS: The investigation enrolled 24 patients in MM remission, who were observed to have monoclonal LC secretion at onset. Group 1 included 14 patients with CN; Group 2 consisted of 10 patients with normal renal function (a comparison group). The compared groups did not differ in the number of serum and urinary monoclonal LCs. Genomic DNA was extracted from the peripheral blood samples of patients. The nucleotide sequence of exons 4 and 5 of the UM gene was determined by the Sanger method. RESULTS: No differences were found in the frequency of polymorphisms depending on the severity of kidney injury. The missense mutation p.142R>R/Q in the UM gene, which had not been previously described, was discovered. CONCLUSION: The patients with MM were not found to have statistically significant differences in the frequency and nature of polymorphisms of exons 4 and 5 in the UM gene, including in the area encoding D8C, in CN without kidney injury.

[Absolute numbers of peripheral blood CD34+ hematopoietic stem cells prior to a leukapheresis procedure as a parameter predicting the efficiency of stem cell collection]. / Absoliutnoe kolichestvo gemopoéticheskikh stvolovykh kletok CD34+ v perifericheskoi krovi pered protseduroi leikafereza kak parametr, prognoziruiushchii éffektivnost' sbora stvolovykh kletok.

AIM: To identify a parameter predicting a collection of at least 2·106 CD34+ hematopoietic stem cells (HSC)/kg body weight per leukapheresis (LA) procedure. SUBJECTS AND METHODS: The investigation included 189 patients with hematological malignancies and 3 HSC donors, who underwent mobilization of stem cells with their subsequent collection by LA. Absolute numbers of peripheral blood leukocytes and CD34+ cells before a LA procedure, as well as a number of CD34+ cells/kg body weight (BW) in the LA product stored on the same day were determined in each patient (donor). RESULTS: There was no correlation between the number of leukocytes and that of stored CD34+ cells/kg BW. There was a close correlation between the count of peripheral blood CD34+ cells prior to LA and that of collected CD34+ cells calculated with reference to kg BW. CONCLUSION: The optimal absolute blood CD34+ cell count was estimated to 20 per µl, at which a LA procedure makes it possible to collect 2·106 or more CD34+ cells/kg BW.

[Multiple myeloma: Maintenance therapy after autologous hematopoietic stem cell transplantation, depending on minimal residual disease]. / Mnozhestvennaia mieloma: podderzhivaiushchaia terapiia posle transplantatsii autologichnykh gemopoéticheskikh stvolovykh kletok v zavisimosti ot minimal'noi ostatochnoi bolezni.

AIM: To determine the efficiency of maintenance therapy with bortezomib in patients with multiple myeloma (MM) who have achieved complete remission (CR) after autologous hematopoietic stem cell (auto-HSCT), depending on the presence of minimal residual disease (MRD). SUBJECTS AND METHODS: In January 2014 to February 2016, fifty-two MM patients (19 men and 33 women) aged 24 to 66 years (median 54 years), who had achieved CR after auto-HSCT, were randomized to perform maintenance therapy with bortezomib during a year. On day 100 after auto-HSCT, all the patients underwent immunophenotyping of bone marrow plasma cells by 6-color flow cytometry to detect MRD. Relapse-free survival (RFS) was chosen as a criterion for evaluating the efficiency of maintenance therapy. RESULTS: After auto-HSCT, MRD-negative patients had a statistically significantly higher 2-year RFS rate than MRD-positive patients: 52.9% (95% confidence interval (CI), 35.5 to 70.5%) versus 37.2% (95% CI, 25.4 to 49.3%) (p=0.05). The presence of MRD statistically significantly increased the risk of relapse (odds ratio 1.7; 95% CI, 1.2 to 3.4; p=0.05). Two-year cumulative risk of relapse (using the Kaplan-Meier) after auto-HSCT did not statistically significantly differ in MRD-negative patients receiving (n=15) and not receiving (n=10) maintenance therapy with bortezomib (p=0.58). After completion of maintenance treatment, 42% of the MRD-positive patients achieved a negative status. In the MRD-positive patients who had received maintenance therapy, the average time to recurrence was 5 months longer than that in the naïve patients: 17.3 versus 12.3 months. CONCLUSION: The MRD status determined in MM patients who have achieved CR after auto-HSCT is an important factor for deciding on the use of maintenance therapy.

[Prognostic value of 1q21 amplification in multiple myeloma]. / Prognosticheskoe znachenie amplifikatsii 1q21 pri mnozhestvennoi mielome.

AIM: To determine the prevalence of amp1q21 and its relationship to the clinical manifestations of multiple myeloma (MM). SUBJECTS AND METHODS: In December 2009 to March 2016, a total 134 patients aged 30 to 81 years (median 57 years) underwent a pretreatment FISH-study of bone marrow (BM) with centromeric and locus-specific DNA probes to identify amp1q21, t(11;14), t(4;14), t(14;16), t(14;20), t(6;14), trisomies of chromosomes 5, 9, 15, del13q14, del17p13/TP53, and t(8q24)/cMYC. Induction therapy with bortezomib-containing cycles was performed. Autologous stem cell transplantation was carried out in 48 patients. The median follow-up of patients was 19.3 months (3.2-77.4 months). Disease progression was diagnosed in 69 (51.5%) patients; 12 patients also underwent FISH study during disease progression. RESULTS: At the onset of MM, amp1q21 was detected in 53 (39.6%) patients. The overall 5-year survival rate in patients with amp1q21 was almost 2 times lower than that in those without amp1q21 (43.5 and 79.4%, respectively; p=0.07). The overall 5-year survival rate in patients with one extra copy of 1q21 (only 3 copies) was 67.3%, that in those with 2 or more extra copies of 1q21 (only 4-7 copies) was 20.9% (p=0.0016). Nine (75%) of the 12 patients examined during disease progression were found to have amp1q21: 2 cases were detected in the period of progression to have amp1q21 in its absence at disease onset; 7 cases had amp1q21 both at MM onset and progression; however, the number of copies of 1q21 was unchanged. CONCLUSION: Аmp1q21 is one of the most common chromosomal abnormalities in patients with new-onset MM and may appear in the course of disease progression. The presence of аmp1q21 is an important prognostic factor and must have to be included in the diagnostic study both at disease onset and progression.

[Current approaches to treating of patients with multiple myeloma with renal failure: Questions and proofs]. / Sovremennye podkhody k lecheniiu bol'nykh mnozhestvennoi mielomoi s pochechnoi nedostatochnost'iu: voprosy i dokazatel'stva.

Renal failure (RF) is detected in 20-30% of patients at the onset of multiple myeloma (MM), in 50% of patients during its progression. The advent of new, highly effective agents has considerably expanded the possibilities of treatment in MM patients. Unfortunately, patients with RF, especially those with severe RF, were not included in the majority of investigations. The available data are based on the results of treatment in small groups of patients generally without the morphological identification of nephropathies, with varying severity of RF, which explains significant differences in renal response rates. This review analyzes the results of the most important studies and gives recommendations for treatment in accordance with national and international standards.

[Light-chain deposition disease is a hematologic problem]. / Bolezn' depozitov legkikh tsepei ­ gematologicheskaia problema.

AIM: To analyze clinical and laboratory data and treatment results in patients with light-chain deposition disease (LCDD). SUBJECTS AND METHODS: Nine patients with LCDD and kidney injury were examined. The diagnosis was based on the results of light and immunofluorescence microscopy of renal biopsy specimens. All the patients received bortezomib, cyclophosphamide, and dexamethasone (VCD) induction therapy. RESULTS: Six patients were diagnosed with multiple myeloma; in 3 patients LCDD was considered within monoclonal gammopathy manly involving the kidney. By the initiation of therapy, all the patients were diagnosed as having chronic kidney disease (Stage III (n=2), Stage IV (n=2), and dialysis-related renal failure (n=5)). After the VCD treatment, 7 of 9 patients achieved a hematologic response. Second-line therapy with lenalidomide proved to be effective in the other 2 cases. Five patients achieved complete remission; 3 had a very good partial remission. Thereafter, 2 patients received high-dose melphalan chemotherapy and autologous hematopoietic stem cell transplantation. Better renal function was noted in only 2 cases. CONCLUSION: Despite the high efficiency of therapy aimed to reduce monoclonal light chains; improved renal function was observed in only 2 (22%) patients. Such low rates of a renal response were due to the late initiation of therapy.

[Secondary monoclonal gammopathy after bone marrow autotransplantation as a cause of worse renal function in light chain immunoglobulin deposition disease].

The paper describes a clinical case of a female woman with nephropathy due to light chain deposition disease caused by secretion of κ Bence-Jones protein. Complete immunochemical remission was achieved after induction therapy using a bortezomib + cyclophosphamide + dexamethasone regimen. Renal function remained unchanged (glomerular filtration rate 16 ml/min), there was a reduction in proteinuria from 5.8 to 2.6 g/day. High-dose melphalan (200 mg/m2) chemotherapy with peripheral blood stem cell autotransplantation was performed as consolidation of remission. A year posttransplantation, there was no secretion of κ light chains; however, monoclonal IgG lambda emerged in a quantity of 3.2 g/l. At the same period, nephrotic syndrome became progressive (daily proteinuria 12 g) and dialysis-dependent renal failure developed. A repeat renal biopsy specimen revealed changes, suggesting that there was a decrease in renal deposits of κ light chains. Simultaneously with this, the obvious negative trend as progressive nephrosclerosis and fixation of IgG and λ light chains in the glomeruli (in the sclerotic areas) cause IgGλ monoclonal protein to be involved in the genesis of further kidney injury. Attention is also paid to different characteristics of capillary wall deposits by density (according to the electron microscopic findings), which may point to their different qualitative composition and possibly different formation duration. Papaprotein Gλ disappeared after a year without therapy, suggesting its reactivity. The findings confirm that worse renal function is caused by the action of paraprotein Gλ due to secondary (after autologous hematopoietic stem cells transplantation) monoclonal gammopathy.

Mitochondrial thioredoxin reductase regulates major cytotoxicity pathways of proteasome inhibitors in multiple myeloma cells.

It is generally accepted that intracellular oxidative stress induced by proteasome inhibitors is a byproduct of endoplasmic reticulum (ER) stress. Here we report a mechanism underlying the ability of proteasome inhibitors bortezomib (BTZ) and carfilzomib (CFZ) to directly induce oxidative and ER stresses in multiple myeloma (MM) cells via transcriptional repression of a gene encoding mitochondrial thioredoxin reductase (TXNRD2). TXNRD2 is critical for maintenance of intracellular red-ox status and detoxification of reactive oxygen species. Depletion of TXNRD2 to the levels detected in BTZ- or CFZ-treated cells causes oxidative stress, ER stress and death similar to those induced by proteasome inhibitors. Reciprocally, restoration of near-wildtype TXNRD2 amounts in MM cells treated with proteasome inhibitors reduces oxidative stress, ER stress and cell death by ~46%, ~35% and ~50%, respectively, compared with cells with unrestored TXNRD2 levels. Moreover, cells from three MM cell lines selected for resistance to BTZ demonstrate elevated levels of TXNRD2, indirectly confirming its functional role in BTZ resistance. Accordingly, ectopic expression of TXNRD2 in MM cell xenografts in immunocompromised mice blunts therapeutic effects of BTZ. Our data identify TXNRD2 as a potentially clinically relevant target, inhibition of which is critical for proteasome inhibitor-dependent cytotoxicity, oxidative stress and ER stress.

[Autologous hematopoietic stem cell transplantation as late high-dose consolidation in adult patients with T-cell lymphoblastic leukemias: Results of a Russian multicenter study].

AIM: To analyze the efficiency of the ALL-2009 protocol (ClinicalTrials.gov NCT01 193933) in patients with T-cell leukemias, particularly the role of autologous hematopoietic stem cell transplantation (auto-HSCT) after non-myeloablative BEAM conditioning, followed by maintenance therapy. SUBJECTS AND METHODS: Since 2009, the ALL-2009 study has enrolled 90 patients with T-cell acute lymphoblastic leukemia (T-ALL), the treatment results were assessed in 86 patients: 6 and 28 patients underwent allogeneic HSCT and auto-HSCT, respectively. A landmark analysis was used to compare survival rates in patients who had undergone auto-HSCT and in those who had not. For this, the median time from complete remission to the date of auto-HSCT was determined (the median was 6 months). Then to compare with the auto-HSCT group, only 27 patients who had been in complete remission for 6 months or more were included in a chemotherapy group. RESULTS: The achievement of complete remission in patients with thymic T-ALL (100%) was significantly higher than in those with early (85.7%) or mature (70%) variants. The patients with early and mature T-ALL as compared to those with thymic T-ALL showed high death rates in the remission induction (7.4 and 10% versus 0) and the patients with mature T-ALL had a.higher proportion of refractory forms (20% versus 0). The 5-year overall and relapse-free survival rates in all the T-ALL patients were 66 and 76%, respectively. After auto-HSCT, the risk of recurrence was 0% versus 21% after chemotherapy (p=0.03). The relapse-free survival rates significantly differed in the auto-HSCT and non-auto-HSCT groups: 100 and 66%, respectively (p=0.047). CONCLUSION: The long-term survival rates obtained during this multicenter study in the T-ALL patients treated according to the ALL-2009 protocol, the basis for which is the principle of continuity of cytostatic effects, are exclusively optimistic. Late consolidation with auto-HSCT following non-myeloablative BEAM conditioning, followed by maintenance therapy, considerably reduces the risk of recurrence.

[Dialysis-dependent renal failure in patients with multiple myeloma: Reversibility factors].

AIM: To establish the reversibility factors of dialysis-dependent renal failure (RF) in patients with multiple myeloma (MM) treated according to bortezomib-containing programs. SUBJECTS AND METHODS: The efficiency of treatment according to bortezomib-containing programs was evaluated in 40 patients with first diagnosed MM and dialysis-dependent RF. Prior to treatment, 34 patients underwent needle renal biopsy. The early mortality rate was 5%. RESULTS: After treatment according to bortezomib-containing programs, 83% of the patients could achieve a hematologic response, including 66% who had complete and very good partial remission (CR and vgPR). A renal response (RenR) was observed in only 26% of the patients. RenR to antitumor therapy was found to be determined by the morphological variant of nephropathy. Improved kidney function was observed only in cast nephropathy (CN) and absent in other types of kidney injury. In CN, the rate of RenR depends on the degree of renal tubulointerstitial fibrosis at the initiation of treatment. Kidney function improved in 20% of the patients with disseminated tubulointerstitial fibrosis and in 57% of those with minimal fibrotic changes (p=0.04). To achieve RenR, it is important to have an early antitumor response in addition to baseline morphological changes in the nephrobiopsy specimen. When the number of monoclonal light chains (LC) in urine was reduced to 100 mg/day after 2 cycles of induction therapy, RenR was 55%; with a lower antitumor response it was as high as 28% (p=0.04). A LC decrease to the values of vgPR after 2 cycles of induction therapy was noted in only 32% of the patients; 44% of the patients achieved vgPR or CR after an average of 6 (3-13) therapy cycles. CONCLUSION: In MM patients with dialysis-dependent RF, RenR was caused by the morphological variant of kidney injury and by the degree of tubulointerstitial fibrosis at the therapy initiation, as well as by the rate at which monoclonal LCs reduced.