Identification of patients at high risk of secondary extramedullary multiple myeloma development.

Multiple myeloma (MM) is characterized by malignant plasma cell infiltration of the bone marrow. In extramedullary multiple myeloma (EMD), a subclone of these cells migrates out of the bone marrow. Out of 4 985 MM patients diagnosed between 2005 and 2017 in the Czech Republic, we analyzed 234 secondary EMD patients to clarify risk factors of secondary EMD development. We found younger age [<65 years; odds ratio (OR) 4·38, 95% confidence interval (CI): 2·46-7·80, P < 0·0001], high lactate dehydrogenase (LDH) levels (>5 µkat/l; OR 2·07, 95% CI: 1·51-2·84, P < 0·0001), extensive osteolytic activity (OR 2·21, 95% CI: 1·54-3·15, P < 0·001), and immunoglobulin A (IgA; OR 1·53, 95% CI: 1·11-2·11, P = 0·009) or the non-secretory type of MM (OR 2·83; 95% CI: 1·32-6·04, P = 0·007) at the time of MM diagnosis to be the main risk factors for secondary EMD development. Newly diagnosed MM (NDMM) patients with subsequent EMD had inferior median progression-free (PFS) and overall (OS) survival when compared to NDMM patients without future EMD [mPFS: 13·8 months (95% CI: 11·4-16·3) vs 18·8 months (95% CI: 17·7-19·9), P = 0·006; mOS: 26·7 months (95% CI: 18·1-35·4) vs 58·7 months (95% CI: 54·8-62·6), P < 0·001]. We found that NDMM patients with specific risk factors associated with secondary EMD development have a more aggressive disease course before secondary EMD develops.

CAR-T cells for the treatment of relapsed/refractory multiple myeloma in 2022: efficacy and toxicity.

Chimeric antigen receptor (CAR)-T cells are a new treatment modality in various hematological malignancies, including relapsed/refractory multiple myeloma (RRMM). RRMM patients have a poor prognosis, and their treatment options are limited. Currently available data from clinical trials on CAR-T cell therapy have demonstrated efficacy and manageable toxicity in RRMM. The CAR-T cells in RRMM mostly focus on already known cellular targets, such as B-cell maturation antigen (BCMA). CAR-T cells focusing on other targets have been analyzed in various clinical trials as well. Cytokine release syndrome (CRS), specific neurotoxicity, and hematological toxicity are the main adverse events (AE); according to the clinical trials, they are mostly mild with a low incidence of grade 3 or higher toxicities. The autologous CAR-T cell therapy against BCMA (ide-cel and cilta-cel) shows the best efficacy with an overall response rate and a median progression-free survival in RRMM. Both ide-cel and cilta-cel have already been approved by the FDA. Currently, the main controversies in the routine use of CAR-T cells are high treatment costs and unknown long-term efficacy. In this review, we summarize the current overview of CAR-T cell therapies in RRMM in 2021 with various targets for CAR-T cells and their efficacy, safety, and possible limitations. Future prospective clinical trials are needed to clarify the optimal role of CAR-T cells in MM therapy.

Real-world evidence of efficacy and safety of pomalidomide and dexamethasone in relapsed/refractory multiple myeloma patients: Czech registry data.

We assessed the outcomes of pomalidomide and dexamethasone treatment in relapsed/refractory multiple myeloma (RRMM) patients with ≥1 prior line of therapy. We analyzed the data of all RRMM patients treated with pomalidomide and dexamethasone at nine Czech centers between 2013 and 2018. The source of the data was the Registry of Monoclonal Gammopathies of the Czech Republic. Primary endpoints included response rates based on International Myeloma Working Group criteria and survival measures, including progression-free survival (PFS) and overall survival (OS). Secondary endpoints were toxicities and previous treatment patterns, including refractory to lenalidomide, and their impact on final outcomes. The overall response rate was 51.8% and the clinical benefit rate (including patients with minimal response) was 67.1%, with 0.6% of complete responses, 8.5% of very good partial responses, and 42.1% of partial responses (PR). Overall, 16.5% of patients had a minimal response, and 32.3% had stable disease /progression. Median PFS was 8.8 months and the median OS was 14.2 months. In patients who achieved ≥PR, the median PFS and OS were significantly longer compared to non-responders (median PFS (12.1 vs. 4.5 months, p≤0.001 respectively), median OS (22.1 vs. 7.7 months, p≤0.001, respectively). The most frequent adverse events (AEs) were neutropenia (29.9%) and anemia (18.9%), non-hematological AEs included infections (14.6%) and fatigue (7.3%). Our analysis confirmed the effectiveness of pomalidomide and dexamethasone in a real-world setting. This therapy achieved reasonable outcomes comparable to the data from clinical trials even though this was an unbiased cohort of patients.

Multicentric Castlemans disease. Symptoms, diagnostics and therapy.

Castleman disease (CD) describes a group of heterogeneous hematologic disorders with characteristic histopathological features. CD can present with unicentric (UCD) or multicentric (MCD) regions of lymph node enlargement. Some cases of MCD are caused by human herpesvirus-8 (HHV-8), whereas others are HHV-8-negative/idiopathic (iMCD). Treatment of iMCD is challenging, and outcomes can be poor. In this paper, we briefly report about symptoms of iMCD and about the International, evidencebased consensus diagnostic criteria for HHV-8-negative/idiopathic multicentric Castleman disease and International evidence based consensus treatment guidelines for idiopathic multicentric Castleman disease.

IgG4-related disease. Clinical manifestation differential diagnosis and recent International Diagnostic Criteria for IgG4-related disease.

Immunoglobulin G4- related disease (IgG4-RD) is a rare systemic fibro-inflammatory disorder. Autoimmune pancreatitis is the most frequent manifestation of IgG4-RD. However, IgG4-RD can affect any organ such as salivary glands, orbits, retroperitoneum, prostate and many others. Recent research enabled a clear clinical and histopathological description of IgG4-RD and in 2019 four Clinical phenotypes of IgG4-related disease were described. Diagnosis is based on morphological examination with typical findings of lymphoplasmocellular inflammation, storiform fibrosis and obliterative phlebitis in IgG4-RD biopsies and the tissue invading plasma cells largely produce IgG4. Elevated serum IgG4 levels are found in many but not all patients. New diagnostic criteria for IgG4-RD have been published recently in 2019 and 2021. This review summarizes current knowledge on pathophysiology, clinical manifestations, diagnosis and differential diagnosis of IgG4-RD from the point of view 2022 and in next article brings overview of the IgG4-RD therapy.

Outcome of COVID-19 infection in 50 multiple myeloma patients treated with novel drugs: single-center experience.

Infections are the primary cause of morbidity and mortality in multiple myeloma (MM) patients (pts). The aim of our retrospective analysis was to evaluate incidence and course of COVID-19 infection in a cohort of 351 MM outpatients treated with novel drugs. COVID-19 disease was detected in 50/351 pts (14%); median age was 68 years. Gender, ISS stage, and last treatment lines were as follows: male 32, female 18; ISS-I 19, ISS-II 20, ISS-III 11; daratumumab-based 15, lenalidomide-based 12, bortezomib-based 17, other 6. Positive PCR test at COVID-19 diagnosis was present in all pts; anti-myeloma treatment was interrupted. Hospitalizations for COVID-19 pneumonia were necessary for 28/50 pts (56%), 18/50 pts (36%) in standard unit (SU) 10/50 pts (20%) in intensive care unit (ICU), and 9/50 pts (18%) died. The statistically significant parameters for COVID-19 hospitalization were as follows: responsive versus non-responsive disease (p = 0.027), ECOG performance status 0-2 versus ≥ 3 (p = 0.014), presence of comorbidities (0-1 versus ≥ 2, p = 0.043). The statistically significant factors for COVID-19 death were as follows: ECOG 0-2 versus ≥ 3 (p = 0.001), presence of comorbidities (0-1 versus ≥ 2, p = 0.007), serious course of COVID-19 disease with ICU hospitalization (SU versus ICU, p = 0.001). None of the other studied risk factors was associated with poor outcome (age, gender, ISS stage, immunoparesis, type of anti-myeloma treatment). Full recovery from COVID-19 infection was observed in 41/50 pts (82%) in median of 32 days. The course of COVID-19 disease in MM pts was mostly moderate or serious with 56% of hospitalizations and 18% of deaths.

Bortezomib-based therapy for newly diagnosed multiple myeloma patients ineligible for autologous stem cell transplantation: Czech Registry Data.

OBJECTIVES: This study compared the use of bortezomib in different combination regimens in newly diagnosed multiple myeloma (NDMM) patients who were transplant ineligible. PATIENTS AND METHODS: We analyzed data from the Registry of Monoclonal Gammopathies (RMG) of the Czech Myeloma Group (CMG) to provide real-world evidence of outcome for 794 newly diagnosed MM transplant ineligible patients. The most frequently used regimen was VCd (bortezomib-cyclophosphamide-dexamethasone) (47.5%) over VMP (bortezomib-melphalan-prednisone) (21.7%), BDd (bortezomib-doxorubicin-dexamethasone) (9.8%), and VTd (bortezomib-thalidomide-dexamethasone) (2.9%). RESULTS: The overall response rate (ORR) was 69.2% (478/691), including 12.6% (≥ CR); 34.7% very good partial responses (VGPR); and 21.9% partial responses (PR). Among triplet regimens, VMP was the most effective regimen compared to VCd, BDd, and VTd. Median PFS was 22.3 vs. 18.5 vs. 13.7 vs. 13.8 mo, (P = .275), respectively, and median OS was 49 vs. 41.7 vs. 37.9 vs. 32.2 mo (P = .004), respectively. The most common grade 3-4 toxicities were anemia in 17.4% and infections in 18% of patients. CONCLUSION: Our study confirmed that bortezomib-based treatment is effective and safe in NDMM transplant ineligible patients, especially VMP, which was identified as superior between bortezomib-based induction regimens not only in clinical trials, but also in real clinical practice.

Prognostic significance of lymphocyte patterns in multiple myeloma patients after autologous transplant.

Despite the high efficacy of current induction regimens, most multiple myeloma (MM) patients relapse over time. The link between changes in the immune system and the prognosis of the disease is still not entirely clear. Therefore, we analyzed whether the pattern of bone marrow (BM) lymphocytes during routine BM examination after autologous stem cell transplant (ASCT) is related to disease prognosis or MRD negative complete remission. From 2009 to 2018, 98 MM patients underwent routine BM testing after the first ASCT. Using multi-parametric flow cytometry, twelve BM lymphocyte subtypes were analyzed. In 60% of patients who achieved a complete response (CR), MRD by flow cytometric analysis (sensitivity threshold 10-6) was evaluated. We found an association of relative proportion of BM lymphocyte subtypes with treatment response, progression-free survival (PFS), overall survival (OS), and minimal residual disease (MRD) negativity. Higher relative proportion of memory B cells was associated with inferior median PFS [HR 1.089 (95% CI: 1.023-1.160), p=0.008] and median OS [HR 1.170 (95% CI: 1.074-1.274), p<0.001]. In non-responding patients (minimal response and worse), higher proportion of memory B cells was found when compared to patients achieving CR [3.8% (range 0.5-35.0) vs. 1.0% (range 0.1-12.5); p=0.001]. No significant association of BM lymphocyte subtypes proportion with MRD negative CR was found. Our results show that changes in BM lymphocyte subsets including memory B cells may have prognostic value in MM patients after ASCT.

Lymphangiomatosis - very rare disease of the lymphatic vessels.

Lymphangiomatosis is rare disease, we can find this entity in differential diagnosis of osteolytic leasions of bones of unknown origin. Typical sign for lymphangiomatosis is proliferation of lymphatic tissue with production of lymphangiomas in various organs and systems. Clinical manifestation of disease is variable, involvement of lungs and bone is typical. In our article we present recent classification of lymphatic tissue neoplasias, their clinical symptoms and treatment possibilities.

Therapy of 3 patients with Erdhiem-Chester disease with cladribin or cladribin in combination with cyclophosphamide. Case report and review of the therapy.

Three adult patients with confirmed Erdheim-Chester disease (ECD) are followed at our department. Cladribine in monotherapy or in combination with cyclophosphamide were used for first line therapy. The median number of cycles of cladribine or cladribine and cyclophosphamide was 7 (range 6-8). In two cases complete response was achieved, in one case this therapy achieved no response. The duration of response is in one case 11 years, in second case the follow up is too short for evaluation of response duration. In case of no-response to cladribine and cyclophosphamide stabilisation of disease was achieved with anakinra. The tolerance was good without any toxicity grade II and higher. Cladribin and cyclophosphamide is one option for treatment of Erdheim-Chester disease.

Transformation of IgM-MGUS into Waldenström´s macroglobulinemia in two of six patients treated for Schnitzler´s syndrome.

Transformation of IgM-MGUS into Waldenström´s macroglobulinemia in two of six patients treated for Schnitzler´s syndrome Schnitzler´s syndrome is a very rare, adult-onset, apparently acquired autoinflammatory disease. Chronic urticarial rash and symptoms of systemic inflammation including fever, arthralgia and bone pain with the presence of monoclonal immunoglobulin M (IgM), rarely IgG, are among hallmarks of the disease. We performed a retrospective study of 6 patients (5 men, 1 woman) diagnosed with Schnitzler´s syndrome fulfilling the Strasbourg criteria who had been treated at our centre in the University Hospital Brno from 2007 to 2021. Median age at diagnosis was 54 (45-67) years, median follow up was 8 (3-14) years. All 6 patients had IgM κ monoclonal gammopathy, increased CRP and/or erythrocyte sedimentation rate and arthralgia or bone pain, 4 patients suffered from fever, three had leucocytosis 10 × 109/L and lymphadenopathy was found in one patient. 18FDG-PET/CT scan with low-dose total body CT became a part of the initial baseline assessment in 5 patients with suspected Schnitzler´s syndrome, while Na18F-PET/CT was used in one patient to confirm the presence of osteosclerotic leasions as a criterion of the disease. All patients had osteosclerotic or hyperostotic bone lesions detected by low-dose CT examination, with increased 18FDG uptake in illiac and femoral bone marrow. The patient with Na18F-PET/CT scan revealed intensive abnormal tracer uptake with Na18F-PET/CT being more sensitive for detection of osteosclerotic lesions in Schnitzler´s syndrome than 18FDG-PET/CT. All patients were treated with daily subcutaneous anakinra without any adverse events, with excellent clinical results. We observed complete disappearance of urticaria and other symptoms persisting during years of anakinra administration. IgM-MGUS transformed into Waldenström´s macroglobulinemia in two of six patients, but only one patient developed symptoms requiring RBD (Rituximab, Bendamustin, and Dexamethasone) treatment, which induced almost complete remission of the disease. Successful RBD therapy enabled to prolong intervals of maintenance anakinra from 24 to 48 hours with almost complete control of urticarial rash and other symptoms. We suggest close monitoring of patients with Schnitzler´s syndrome to early capture potential transformation into Waldenström´s macroglobulinemia with succesful treatment of both conditions.

Hereditary hemorrhagic telangiectasia (OslerWeberRendu syndrome) - Part II. Pharmacological therapy and international guidelines for the therapy 2020.

Hereditary hemorrhagic telangiectasia also known as Osler-Weber-Rendu syndrome, is an disorder that causes abnormal blood vessel formation with bleeding. Inhibition of angiogenesis amelioretes bleeding complication. Anti-angiogenic agents such as bevacizumab, aflibercept, thalidomid, lenadomid and other new anti-angiogenic thyrosinkinase inhibitors, as well as sirolimus and takrolimus have emerged as a promising systemic or local therapy in reducing bleeding complications but are not curative. Other pharmacological agents include iron supplementation, antifibrinolytics and hormonal treatment. This review concentrates on new anti-agioproliferative drugs with effect in HHT- discusses the new biology of HHT, management issues that face the practising hematologist, and considerations of future directions in HHT treatment.

Complete remission of necrobiotic xanthogranuloma after disappearance of monoclonal immunoglobulin induced by bortezomib, lenalidomid and dexamethasone.

Necrobiotic xanthogranuloma (NXG) is a rare chronic condition, belonging to the group non-Langerhans cell histiocytoses, which is relevant due to the possibility of extracutaneous involvement and association with systemic diseases, particularly monoclonal gammopathy, MGUS and multiple myeloma. The case reported here NXG was diagnosed after 1 years of evolution in patient with asymptomatic multiple myeloma. After treatment with bortezomib, lenalidomid and dexamethasone, there was evident abrupt decrease of monoclonal immunoglobulin to not measurable level (complete remission of multiple myeloma) and in the same time was evident disappearance of cutaneous and hepatic lesions of NXG on FDG-PET/CT. The etiopathogenetic association of monoclonal immunoglobulin with NXG is documented in this case report with disappearance of NXG in the time of disappearance of monoclonal immunoglobulin.

Identification of patients with smouldering multiple myeloma at ultra-high risk of progression using serum parameters: the Czech Myeloma Group model.

Smouldering multiple myeloma (SMM) presents without MM defining symptoms. We aimed to identify patients with SMM with an 80% risk of progression within 2 years using only serum parameters. In total, 527 patients with SMM were included and divided into a training group (287 patients from the Czech Myeloma Group [CMG]) and an independent validation group (240 patients from Heidelberg). The median follow-up was 2·4 and 2·5 years, respectively. Progression to MM occurred in 51·9% of the CMG and 38·8% of the Heidelberg patients, respectively. The median risk of progression was 11·0% (CMG) and 9·7% (Heidelberg) per year, during the 5 years after diagnosis. A serum involved/uninvolved free light-chain ratio of >30, immunoparesis, and serum monoclonal (M) protein of ≥2·3 g/dl emerged as powerful predictors of 2-year progression rate with a hazard ratio (HR) of 2·49 (95% confidence interval [CI] 1·49-4·17), HR of 2·01 (95% CI 1·36-2·96) and HR of 2·00 (95% CI 1·44-2·79) (P < 0·001) in univariate Cox regression analysis, respectively. Based on this, the CMG model identified patients with SMM with a 2-year risk of progression of 78·7% (95% CI 53·1-95·7; HR 6·8; P < 0·001, CMG) and 81·3% (95% CI 47·1-98·8; HR 38·63; P < 0·001, Heidelberg). Serum parameters in the CMG model allow identification of patients with SMM with an 80% risk of progression to symptomatic MM within 2 years.

Dynamics of tumor-specific cfDNA in response to therapy in multiple myeloma patients.

OBJECTIVES: Progress in multiple myeloma treatment allows patients to achieve deeper responses, for which the assessment of minimal residual disease (MRD) is critical. Typically, bone marrow samples are used for this purpose; however, this approach is site-limited. Liquid biopsy represents a minimally invasive and more comprehensive technique that is not site-limited, but equally challenging. METHODS: While majority of current data comes from short-term studies, we present a long-term study on blood-based MRD monitoring using tumor-specific cell-free DNA detection by ASO-qPCR. One hundred and twelve patients were enrolled into the study, but long-term sampling and analysis were feasible only in 45 patients. RESULTS: We found a significant correlation of quantity of tumor-specific cell-free DNA levels with clinically meaningful events [induction therapy (P = .004); ASCT (P = .012)]. Moreover, length of cfDNA fragments is associated with better treatment response of patients. CONCLUSIONS: These results support the concept of tumor-specific cell-free DNA as a prognostic marker.

Systemic inflammatory response with high CRP values as the dominant symptom of multiple myeloma.

A man aged 60 years was examined for intense inflammatory response, night sweats, subfebrile and later febrile temperatures and a weight loss of 18 kg in 7 months. CRP was 270 mg / l, i.e. more than 20 times the upper limit of the physiological range. Reactive leukocytosis (10 × 109/l), thrombocytosis (530 × 109/l), increased fibrinogen (greater than 7 g/l), and anemia with hemoglobin of 80 g/l were present. No infection or systemic autoimmune disease has been proven. The patient had normal renal function and had no osteolytic deposits detectable by FDG-PET/CT. The procalcitonin level was not elevated. The bone marrow examination revealed a 30-40% infiltration of proplasmacyte type with admixture of plasmablasts, expressing light chains λ. Monoclonal immunoglobulin IgA λ was at a low concentration of about 8 g/l and the ratio of free light chains κ/λ was 0.13. The extent of bone marrow infiltration and anemia met the criteria for the diagnosis of symptomatic multiple myeloma. Following initiation of the combination therapy using thalidomide, bortezomib and dexamethasone, the maximum decrease in the concentrations of monoclonal immunoglobulin, free light chains and CRP was observed already after the first 2 cycles of treatment. Later, during the following two 2 cycles, the disease began to progress again. The patient underwent successful stem cell collection after the application of cyclophosphamide 2.5 g/m 2 and leukocyte growth factor (G-CSF), and high-dose chemotherapy (melphalan 200 mg/m 2) with the support of stem cell transplantation. At 2 months following high-dose chemotherapy, CRP levels of the physiological range decreased, the blood count was normalized, and monoclonal immunoglobulin was not detectable. Conclusion: The chronic inflammatory response may be due to plasmocytary bone marrow infiltration even if there are no other symptoms of multiple myel-oma present, except for anemia which, however, also involves the inflammatory reaction. In this case, the systemic inflammatory reaction with high CRP levels signalled aggressive behaviour of the disease. Key words: CRP - multiple myeloma - procalcitonin - systemic inflammatory response.

Circulating exosomal long noncoding RNA PRINS-First findings in monoclonal gammopathies.

Multiple myeloma is the second most common hematological malignancy characterized by focal lesions of malignant plasma cells in the bone marrow. These lesions contain subclones that directly influence survival of patients. Bone marrow biopsies are single-site biopsies and thus cannot contain all information about the tumor. In contrast, liquid biopsies analyze circulating cells and molecules that are secreted from all sites of the tumor. Long noncoding RNA molecules are one class of these molecules. We performed a two-phase biomarker study investigating lncRNA expression profiles in exosomes of peripheral blood serum of newly diagnosed multiple myeloma (MM) patients, monoclonal gammopathy of undetermined significance (MGUS) patients in comparison with healthy donors (HD). Surprisingly, this analysis revealed dysregulation of only one exosomal lncRNA PRINS in MM vs HD. Overall, MM and MGUS patients were distinguished from HD with sensitivity of 84.9% and specificity of 83.3%. Our study suggests a possible diagnostic role for exosomal lncRNA PRINS in monoclonal gammopathies patients.

The spectrum of somatic mutations in monoclonal gammopathy of undetermined significance indicates a less complex genomic landscape than that in multiple myeloma.

Monoclonal gammopathy of undetermined significance is a pre-malignant precursor of multiple myeloma with a 1% risk of progression per year. Although targeted analyses have shown the presence of specific genetic abnormalities such as IGH translocations, RB1 deletion, 1q gain, hyperdiploidy or RAS gene mutations, little is known about the molecular mechanism of malignant transformation. We performed whole exome sequencing together with comparative genomic hybridization plus single nucleotide polymorphism array analysis in 33 flow-cytometry-separated abnormal plasma cell samples from patients with monoclonal gammopathy of undetermined significance to describe somatic gene mutations and chromosome changes at the genome-wide level. Non-synonymous mutations and copy-number alterations were present in 97.0% and in 60.6% of cases, respectively. Importantly, the number of somatic mutations was significantly lower in monoclonal gammopathy of undetermined significance than in myeloma (P<10-4) and we identified six genes that were significantly mutated in myeloma (KRAS, NRAS, DIS3, HIST1H1E, EGR1 and LTB) within the monoclonal gammopathy of undetermined significance dataset. We also found a positive correlation with increasing chromosome changes and somatic gene mutations. IGH translocations, comprising t(4;14), t(11;14), t(14;16) and t(14;20), were present in 27.3% of cases and in a similar frequency to myeloma, consistent with the primary lesion hypothesis. MYC translocations and TP53 deletions or mutations were not detected in samples from patients with monoclonal gammopathy of undetermined significance, indicating that they may be drivers of progression to myeloma. Data from this study show that monoclonal gammopathy of undetermined significance is genetically similar to myeloma, however overall genetic abnormalities are present at significantly lower levels in monoclonal gammopathy of undetermined significant than in myeloma.

A first Czech analysis of 1887 cases with monoclonal gammopathy of undetermined significance.

INTRODUCTION: Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition with a risk of malignant conversion. PATIENTS AND METHODS: With the aim to estimate the cumulative risk MGUS progression to hematologic malignancies, we analyzed a nationwide population-based cohort of 1887 MGUS patients from the Czech Registry of Monoclonal Gammopathies (RMG) between 2007 and 2013. RESULTS: During the follow-up period (median 4 years; range 0.6-34.8), progression to hematologic malignancies was observed in 8.6% (162 of 1887) of patients. Factors associated with progression were as follows: M-protein concentration ≥1.5 g/dL, pathological sFLC (<0.26 or >1.65) ratio, bone marrow plasma cells (BMPCs) in cytology >5%, immunoparesis, age ≥69 years, and the level of serum hemoglobin at baseline <12.0 g/dL. Combining these factors, we propose a new risk model (CMG model). The risk of progression at 10 years was 1.6%, 16.9%, 22.9%, 39.4%, and 52.3%, respectively, if 0 (reference group), one, two, three, or four to five risk factors are present (P<.001) with HR 63 times higher compared to the reference MGUS group. CONCLUSION: The new CMG model was established with an advantage for better identification of MGUS patients at low risk.

[Osteoprotective therapy with bisphosphonates or denosumab in patients with multiple myeloma: benefit and risks]. / Osteoprotektivní lécba bisfosfonáty nebo denosumabem u nemocných s mnohocetným myelomem: prínos a rizika.

Bisphosphonates have been used during the complete treatment of multiple myeloma for more than twenty years. They slow osteolysis and thereby contribute to the improvement of quality of life. Their long-term use, however, is related to 2 serious, usually later appearing complications: osteonecrosis of the jaw, occurring in 6-9 % of patients, and rarer atypical bone fractures. Both these complications are very difficult to heal, and all the more emphasis is therefore laid on prevention. This first of all includes discussion about the risk with the patient, followed by a dental checkup before the commencement of therapy and then repeated during its course, as well as reduced use of these drugs for a necessary period of time. However osteonecrosis of the jaw does not only develop as a consequence of bisphosphonate therapy. The complication is also caused by some new drugs (denosumab and others) used in cancer therapies. The text includes an overview of the drugs currently used in cancer treatment, which also increase the risk of appearance of osteonecrosis of the jaw. For patients with multiple myeloma, who achieve the complete or very good partial remission after chemotherapy, it is recommended to administer these drugs for more than 1 year after achieving the positive treatment response, but not longer than for 2 years. Only regarding those who do not reach the good treatment response, bisphosphonates are administered over the long term, as long as osteolytic activity of the disease lasts.Key words: atypical bone fractures - bisphosphonates - drug induced osteonecrosis of the jaw - multiple myeloma.