Introduction . Primary myelofibrosis (PMF) is a clonal disease violating the cell composition, histological topography and stroma in bone marrow (BM). Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is a curative therapy in PMF. Aim  — description of change in the haematopoietic tissue cell composition and stroma, as well as in trabecular bone in allo-HSCT patients with fibrotic PMF. Materials and methods . We studies 24 trephine biopsy samples from nine PMF patients with allo-HSCT at the intervals: I — 1 month prior to, II — past 1–3 months and III — past 4–6 months from allo-HSCT. BM trephine biopsy slides were prepared in a standard histological assay with haematoxylin—eosin and additional staining with Gomori’s silver and Masson’s trichrome. Morphological change was evaluated in reticulin and collagen stroma, bone trabeculae, cellularity and topography of haematopoietic tissue. Results . The BM trephine biopsies of interval I were morphologically distinguished in three types by haematopoietic cellularity, stromal and trabecular sclerotic change. Post-transplant intervals II and III (3–6 months after allo-HSCT) did not reveal these types but showed an evident myelofibrosis and osteosclerosis reduction and signs of a restoring bone remodelling cycle. Myelopoietic lineages recovered in stages: the erythroid germ restored in three, granulocytic — in six months, and megakaryocytic cellularity did not fully recover in six months. Myelopoietic cellularity recovery outpaced blood recovery, which may be due to induced myelodysplasia or disruption of stromal niches. Conclusion . Allo-HSCT leads to the disappearance of PMF-pathognomonic BM morphology reflecting a histological remission. The reduction of myelofibrosis and osteosclerosis and normalisation of the trabecular bone remodelling cycle in post-transplant periods indicates an impact of cell microenvironment on PMF pathogenesis and warrants research into the composition and histological topography of cell microenvironment in PMF.

The publication contains materials of the reports presented at the II Conference “Current Issues of Diagnosis and Treatment of Ph-Negative and Ph-Positive Myeloproliferative Neoplasms” held from 15 to 16 March 2019 at the National Research Center for Hematology (Moscow). The conference was organized to enable professional communication of the clinicians specializing in the treatment of myeloproliferative neoplasms (MPN), and the researchers in the related fields as well as to allow the exchange of views on the implementation of current diagnosis and treatment methods in Ph-negative and Ph-positive MPNs. Reports covered a wide range of rare and non-standard settings. Of particular importance was the opportunity to debate them in detail at panel discussions and interactive sessions. This format of the conference allowed to provide expert opinions in the present publication. It emphasizes the importance of complex diagnosis in MPN using morphological examination of bone marrow core biopsy samples and molecular genetic testing. Accordingly, the second day of the conference was devoted to a thorough analysis of the morphological characteristics of the cases presented and based on bone marrow core biopsy samples.

Introduction. The pathogenesis of myeloproliferative neoplasms is associated with the chimeric gene BCR-ABL1 or with one of the driver mutations in the genes JAK2, MPL and CALR (Calreticulin). However, the classifi cation of the World Health Organization lists no myeloid neoplasms with more than one driver genetic abnormality. Aim. To search for mutations in the genes JAK2, MPL and CALR in patients with BCR-ABL1-positive chronic myeloid leukemia (CML), as well as to evaluate the kinetics of the discovered mutations during tyrosine kinase inhibitor (TKI) therapy. Materials and methods. mRNA and DNA samples isolated from blood and bone marrow cells of 567 CML patients, who underwent periodic monitoring of the BCR-ABL1 transcript level over the 2012–2019 period were included in the study The BCR-ABL1 transcript level was determined using a highly sensitive quantitative real-time polymerase chain reaction. The mutations JAK2V617F and MPLW515L/K were detected using real-time quantitative allele-specifi c polymerase chain reaction. Mutations in the CALR gene were investigated using fragment analysis followed by Sanger sequencing. Results. The combination of the BCR-ABL1, JAK2 and CALR gene mutations among CML patients receiving TKIs was 1.23 % (7/567). Out of these, the combination of BCR-ABL1 with JAK2V617F and the combination of BCR-ABL1 with CALR gene mutations were detected in 0.88 % (5/567) and 0.35 % (2/567) of cases, respectively. During TKI therapy, in 5 out of 7 patients, the level of BCR-ABL1 reached major molecular response (MR). In 4 of these patients, the therapy was discontinued. These patients are currently in molecular remission. In the remaining 2 patients, major MR was not achieved, despite the use of second-generation TKI preparations. Conclusions. The combination of the BCR-ABL1 chimeric gene with gene mutations Jak2 or CALR was a rare event and amounted to 0.88 and 0.35 % of cases, respectively. The combination of BCR-ABL1 with Jak2V617F and CALR mutations does not always impede the achievement of major MR.

Введение. Ишемические цереброваскулярные заболевания (ЦВЗ) — одна из основных причин смертности и инвалидизации в современном мире. Значимой причиной развития ишемических инсультов (ИИ) в относительно молодом трудоспособном возрасте являются Ph-негативные миелопролиферативные заболевания (МПЗ) — клональные заболевания, возникающие на уровне стволовой кроветворной клетки. Цель исследования: оценка вклада гемостазиологических и гемореологических нарушений в развитие нарушения мозгового кровообращения у пациентов с Ph-негативными МПЗ. Материалы и методы. Обследовано 104 пациента в возрасте от 20 до 58 лет (32,7% мужчин, 67,3% женщин) с установленным диагнозом «Ph-негативное МПЗ». Основную группу составил 21 пациент с ИИ. Все пациенты прошли тщательное клиническое и нейровизуализационное обследование. Лабораторные методики включали определение гемореологических, гемостазиологических, фибринолитических показателей, а также идентификацию мутации V617F в гене JAK2. Результаты. У всех пациентов изменения большинства гематологических параметров выходили за рамки нормальных значений вне зависимости от ассоциации с ИИ. Значения гемоглобина и цветовой показатель были выше, а количество тромбоцитов — ниже у пациентов с ИИ по сравнению с аналогичными показателями в группе сравнения. У пациентов с ИИ выявлена высокая представленность маркерной генетической мутации V617F в гене JAK2 (86%). Также определено влияние данной мутации на целый ряд показателей гемореологии и гемостаза. Заключение. Ph-негативные МПЗ являются важным этиологическим фактором развития ИИ. Механизмы тромбообразования при ИИ на фоне МПЗ протекают, по всей видимости, по несколько иным путям в отличие от тромбозов других локализаций. Остается открытым вопрос о поиске единого маркера церебральных тромботических осложнений при МПЗ, что в перспективе может стать основой для персонифицированной профилактики и таргетной коррекции ЦВЗ. Introduction. Ischemic cerebrovascular diseases (ICD) are one of the main causes of death and disability in today’s world. One of the significant ethiological factors for ischemic stroke (IS) in relatively young patients are Ph-negative myeloproliferative diseases (MPD) — clonal diseases occurring at the level of hematopoietic stem cell. Aim: evaluation of hemostasiological and hemorheological disorders in patients with cerebrovascular pathology and Ph-negative MPD. Material and methods. We examined 104 patients (men — 32.7%, women — 67.3%) 20–58 years old with Ph-negative MPD. The main group consisted of 21 patients with IS. Clinical and neuroimaging examinations were performed in all patients. Laboratory methods included determination of hemorheological, hemostasiological, fi brinolytic parameters and identification of V617F mutation in JAK2 gene. Results. All patients had alterations of the majority of hematological parameters beyond the normal range irrespectively from association with IS. Hemoglobin values and color index were higher, and platelet count was lower in patients with IS than in comparison group. A high prevalence of JAK2 mutation (V617F) was noted in IS patients (86%). The infl uence of this mutation on some hemorheological and hemostatic parameters was also determined. Conclusion. Ph-negative MPDs are the important etiological factor of IS development. The mechanisms of thrombus formation in IS patients with MPD are apparently diff erent from thromboses of other localizations. The study underlines the necessity of identifying a uniform marker of cerebral thrombotic complications in MPD which may lead to personified prophylaxis and target correction of MPD.

AIM:To evaluate the efficiency of interferon (IFN) therapy in patients with essential thrombocythemia (ET) and polycythemia vera (PV).SUBJECTS AND METHODS:A total of 61 patients (41 with ET and 20 with PV) were examined. Prior to study enrolment, 44 (72%) patients with ET or PV received one or other therapy (aspirin was not taken into account). The mean Jak2V617F mutant allele at baseline was 23% (6-54%) in the patients with ET and 40% (11-88%) in those with PV. The median time from diagnosis to enrollment was 49 months.RESULTS:The paper presents the clinical and molecular findings of long-term INF-α therapy in patients with ET or PV. The median follow-up was 52 months. Recombinant IFN-α2 showed its ability to induce complete hematologic remission (ET (76%), PV (70%)) and a complete molecular response. 22 (69%) out of 32 patients were noted to have a smaller number of cells with the Jak2V617F mutation. In the patients with PV and in those with ET, the relative reduction in the proportion of cells with the Jak2V617F mutant gene averaged 85% and 56% of the baseline values, respectively. There was a reduction in the proportion of cells expressing the Jak2V617F mutation in both the ET (from 12 to 2.2%; p=0.001) and PV (from 32.7% to 3.2%) groups (р=0.001). Ten (31%) patients achieved a deep molecular remission (≤2% Jak2V617F allele); among them, 5 patients were not found to have Jak2V617F mutation. The obtained molecular response remained in 7 of the 10 patients untreated for 11 to 86 months. The long-term treatment with IFN-α led to normalization of the morphological pattern of bone marrow in 5 of the 7 PV or ET patients.CONCLUSION:Significant molecular remissions achieved by therapy with recombinant interferon-α2 confirm the appropriateness of this treatment option in in the majority of patients with ET or PV.

Aim. To identify the clinical features of latent polycythemia vera (PV) as an independent nosological entity. Subjects and methods. The investigation enrolled 81 patients (50 with extensive (manifest) PV and 31 with latent PV) who had visited the Outpatient Department, Hematology Research Center, Ministry of Health of Russia, in 2014 to October 2015. Results. The gender distribution of the patients was statistically comparable in the analyzed groups. The patients with manifest PV were slightly older than those with latent PV: the median age in the compared groups was 56 and 44 years, respectively. Red blood cell counts, hemoglobin concentrations, and packed cell volume were higher in the patients with manifest PV. Blood platelet counts were higher in the latent PV group. There were no differences in the number of white blood cells in the compared groups. All the patients were JAK2 V617F mutation carriers. The JAK2 allele load was significantly higher in the manifest PV group than in the latent PV group. The compared patient groups differed in the rate of thromboses in the history or at diagnosis. In the patients with latent PV, thromboses were detected in 38% of cases versus 16% in those with manifest PV. In latent PV, there were mainly venous thromboses; abdominal vascular thromboses were diagnosed with a high frequency. Arterial thromboses were revealed in only 2 cases. Conclusion. Chronic myeloproliferative disease that is characterized by the JAK2 V617F mutation, borderline hemoglobin counts, and morphological features of a bone marrow trephine biopsy specimen, which are specific for PV, is an independent PV variant, namely: latent PV.

The paper describes a rare case of formation of paravertebral extramedullary hemopoietic foci in microspherocytic anemia or Minkovsky-Shoffar disease in an adult. Therapeutic splenectomy has led to regression of extramedullary hemopoietic foci, which supports that there is a direct relationship of the above formations to the specific features of the etiology and pathogenesis of microspherocytic anemia.

The article describes a case of cat scratch disease in a female patient with severe chronic pathology. This relatively rare disease was manifested by regional (in the site of microbial intrusion) lymphadenopathy, and general infectious syndrome. The presence of oncohematological process was excluded without biopsy; serologic examination with bartonella antibodies confirmed the diagnosis. Combined treatment with two antibiotics, rifampicin and doxycycline, was successful. The article stresses that general practitioners should be aware of this disease; timely diagnosis and specific treatment are of utter importance.

AIM:To describe original experience in management of Castleman's disease (CD) and review literature data. MATERIAL AND METHODS:Twelve cases of HIV-free CD in patients aged 18-51 years (mean age 36 years) are reported. RESULTS:CD was plasmocell, mixed and hyalinovascular in 6, 2 and 4 patients, respectively. Histological and immunophenotypical characteristics of CD are detailed. Three patients with plasmocell CD died of severe autoimmune anemia. All the patients with hyalinovascular KD variant were treated surgically (enlarged lymph nodes were removed) and achieved remission. CONCLUSION:The diagnosis of plasmocell CD is made after exclusion of infections, collagenoses, autoimmune diseases and lymphomas. Therapy of plasmocell variant of CD has not been developed yet.

: Trepanobiopsy of the bone marrow followed by a histological study was performed in 3 patients with sarcoidosis diagnosed in peripheral lymph node (LN) biopsies. Granulemas revealed in trepanobiopsies were identical to those found in LN. Trepanobiopsy is advisable in patients with sarcoidosis having some changes in hemogram.

AIM:To compare forms of chronic lymphoid leukemia (CLL) regarding mutational status of immunoglobulin variable genes.MATERIAL AND METHODS:We have compared clinical, prognostic and immunophenotypic data obtained on 25 cases with different mutational status of IgV genes. There were 10 patients in the mutated group (median age 49.2 years, male to female ratio = 7:3), and 15 patients in unmutated group (median age 46.5, M:F = 13:2).RESULTS:Statistically significant differences were noted in overall survival and CD38 expression. 5-year overall survival in unmutated group was 35%, in mutated group 80% (p = 0.07). In unmutated group CD38 was expressed on more than 50% of cells in 7 out of 14 patients, while in the mutated group in 0 of 8 patients (p = 0.007). We noted high frequency of VH1-69 gene usage in unmutated group (7 of 15 patients), while in mutated group it was used in only 1 case of 10.CONCLUSION:We confirm the differences between groups of CLL with different mutational status of IgV genes. Highly restricted usage of VH-genes and CD38 expression possibly suggest that unmutated group also arises from antigen driven cells.

The paper presents new findings in favor of recognition of splenic lymphocytoma (SLC). This disease was characterized by A. I. Vorob'ev and M. D. Brilliant in 1982 in terms of detailed clinicomorphological features, prognosis and optimal treatment policy. The study included 52 patients (mean age 53 years) of which 36 were females and 16 males. They were followed up for 5.7 years, on the average. SLC manifested clinically by splenomegaly with minimally enlarged lymph nodes, morphologically by nodular lymphocytic proliferates in the spleen, bone marrow and liver, diffuse or diffuse-nodular proliferation in the lymph node. Peripheral blood contained middle-size lymphoid cells with round nuclei. SLC immunophenotype exhibits moderate or marked expression of CD22 and membrane immunoglobulins, the absence of CD5, CD23 and EM receptor, combination of CR1-/ CR2+. Paraprotein secretion was recorded in 49% of cases. There were frequent autoimmune reactions, especially against erythroid cells and platelets (42%). Optimal therapeutic policy is expectation and eventual splenectomy producing a persistent clinical effect in 94% of patients. In progressive disease long-term therapy with cyclophosphamide is recommended. Thus, SLC is a mature-cell lymphatic tumor growing as a rule in the spleen. Its prognosis in valid therapy is favourable.

An analysis of the results of determination of erythropoietin in the blood plasma of patients with polycythemia vera and data on the kinetics of erythroid cell proliferation led to a conclusion that erythrocytapheresis more than bloodletting stimulated the production of erythropoietin and the cell proliferative potential. Activation of regenerative processes probably determined by deinhibition of the normal clone of bone marrow erythroid cells, can account for the mechanism of a therapeutic effect of erythrocytapheresis in patients with polycythemia vera.