Low incidence of familial occurrence of thrombocythaemia and/or thrombocytosis

Several reports have been published about familial polycythaemia vera (PV) but no information is available about the incidence of thrombocytosis in the same family. In our population of thrombocytosic patients, both with primary thrombocytosis (133 cases) and secondary (37 cases), we found only two family related subjects. One of them had PV and the other essential thrombocytosis (ET). Our results seem to indicate that familial thrombocytosis is a rare phenomenon, much less frequent then familial thrombocytopenia.     

Increased fibroblast colony stimulating activity (F-CSA) in serum of myeloproliferative disorders

Sera of patients with primary myelofibrosis (PMF), primary thrombocythemia (PT), polycythaemia vera (PV) and chronic myeloid leukemia (CML) contained a significantly increased F-CSA (or F-CSAs) compared to those of normal subjects and patients with secondary thrombocytosis (ST). This F-CSA was heat sensitive and had the capacity to promote both proliferation and maturation of normal marrow fibroblast colony-forming cells (CFU-F). This F-CSA seemed to be different from human platelet derived growth factor (PDGF), tumor necrosis factor (TNF) and fibroblast growth factor (FGF) from bovine brain. This F-CSA might be of importance in the pathogenesis of bone marrow fibrosis in myeloproliferative disorders.     

Analysis of megakaryocyte ploidy in patients with thrombocytosis

The DNA content of bone marrow megakaryocytes was analyzed in 24 patients with myeloproliferative disorders, 23 patients with secondary thrombocytosis and 15 normal volunteers using 2-color flow cytometry. Compared with normal controls, the majority of patients with secondary thrombocytosis, polycythemia vera and essential thrombocytosis exhibited a relative increase in higher ploidy (greater than 16N) cells. In contrast, patients with chronic myelogenous leukemia exhibited an increase in lower ploidy cells (less than 16N), with a modal DNA content of 8N. Patients with myeloproliferative disorders tended to show a decrease in the 16N megakaryocyte population compared with patients with secondary thrombocytosis. No correlation between ploidy distribution and platelet count was observed.     

Treatment of thrombocytosis in myeloproliferative disorders with interferon alpha-2a

In an open prospective pilot trial, we tested the effect of recombinant interferon alpha-2 a (rIFN alpha-2 a) on thrombocytosis in myeloproliferative disorders (MPD). Since October 1986, 13 patients with MPD (4 with chronic granulocytic leukemia, 4 with polycythemia vera, 3 with essential thrombocythemia and 2 with myeloid metaplasia) were treated with rIFN alpha-2 a. Platelet counts decreased in all treated patients within 2 to 10 weeks from a median value of 1,050 x 10(9)/l (range 610-1,940 x 10(9)/l) to 340 x 10(9)/l (range 230-495 x 10(9)/l). The response was dose-dependent. In 11 patients we observed a simultaneous reduction of the white blood cell count. Six patients still continue the IFN alpha-2 a therapy. In 7 treatment was discontinued, because of chronic side effects in 3, and because of noncompliance in one. In these patients, thrombocytosis recurred after discontinuation of the therapy. These results show that rIFN alpha-2 a is effective in controlling thrombocytosis in MPD. However, the long-term benefit of interferon in these disorders remains to be established.     

Megakaryocyte precursors (pro- and megakaryoblasts) in bone marrow tissue from patients with reactive thrombocytosis, polycythemia vera and primary (essential) thrombocythemia. An immunomorphometric study

To determine the number of megakaryocyte precursors (pro- and megakaryoblasts), an immunomorphometric study was performed on paraffin-embedded trephine biopsies of the bone marrow using a monoclonal antibody against platelet glycoprotein IIIa. Eighteen control specimens from patients with no evidence of any hematological disorder and a normal platelet count were selected and assessed together with the same number of specimens from patients with reactive thrombocytosis, polycythemia vera rubra (P. vera) or primary (essential) thrombocythemia (PTH). A strikingly proportionate increase in early megakaryocytes occurred in all patients enrolled in this study, compared with the controls. Moreover, there were no significant correlations between counts for precursors or total megakaryocytes per square millimeter of bone marrow with the corresponding values for platelets. This indicates that despite an orderly increase in immature forms in the bone marrow, the number of platelets circulating in the blood is influenced by other additional factors, such as the expanded platelet pool in the enlarged spleen. The non-disproportionate expansion of megakaryocyte precursors extends previous findings on progenitor cells of this lineage in vitro, particularly in PTH. Histological evaluation of the bone marrow of patients with P. vera and PTH indicated that megakaryopoiesis proceeded to the production of appropriate mature forms with no obvious excess of very small or blastic elements.     

Interferon-alfa corrects thrombocytosis in patients with myeloproliferative disorders

Summary During previous therapeutic trials with interferon, decreased levels of peripheral platelet counts have been observed. Taking advantage of this effect, we investigated the efficacy of recombinant interferon (rec-IFN) in the treatment of thrombocytosis in myeloproliferative diseases. A total of 15 patients with polycythemia vera, essential thrombocytosis, or chronic myeloid leukemia received rec-IFN-alfa at initial doses of 25–70×10⁶ units/week; maintenance therapy following week 8 of treatment consisted of 20–35×10⁶ units/week rec-IFN. Observation periods ranged from 24 to 48 weeks. Significant reductions in the number of platelets were noted in all cases; 12/15 patients achieved platelet counts below 440×10⁹/1 and maintained those normal values for at least 4 weeks. The number of bone marrow megakaryocytes, which had been increased prior to treatment, diminished during rec-IFN therapy, while the previously shortened platelet half-life further decreased with rec-IFN treatment. During rec-IFN-induced remission, the plasma levels of platelet factors, the activity of natural killer cells, and platelet aggregation showed changes between slight improvement and normal values. Severe side effects were only observed with the highest rec-IFN doses; dosage adjustments were effective in improving or eliminating all treatment-related symptoms. Rec-IFN may prove to be a valuable therapeutic alternative to cytostatic treatment of thrombocytosis in myeloproliferative disorders.This study was supported in part by the Austrian Research Grant: P4999 and the Ludwig Boltzmann Institute for Gerontology, Vienna, Austria     

The effect of different doses of 32P in the treatment of primary thrombocytosis

We report on a follow up in 23 patients with primary thrombocytosis treated with two different doses of 32phosphorus phosphate (32P). Ten patients with essential thrombocytosis (ET) received 2 mCi and 13 patients with polycythemia vera (PV) received the standard dose of 0.1 mCi/kg b.w. The patients were listed as having a complete response (CR), partial response (PR) or no response (NR) considering platelet count at 3 and 12 months after 32P injection. The results indicate the existence of a clear correlation of the rate of remission with the 32P injected dose. PV patients show, in fact, a percentage of complete remission higher than ET patients. However, the use of higher doses induces more early and long-term complications.     

Primary (essential) thrombocythemia versus polycythemia vera rubra. A histomorphometric analysis of bone marrow features in trephine biopsies

A morphometric analysis of bone marrow biopsies was performed in 25 patients each with clinical diagnoses of primary (essential) thrombocythemia (PTH) and polycythemia vera rubra (P. vera) according to the rigid diagnostic criteria of the Polycythemia Vera Study Group to reveal significant differences in the histomorphologic features between these disorders. In comparison with control specimens of patients without any hematologic disease, megakaryocyte proliferation was most prominent in PTH, even exceeding that of P. vera with concomitant thrombocythemia (11 of 25 cases with a platelet count greater than 600 X 10(9)/L). Moreover, in P. vera there were wide ranges of megakaryocyte sizes, consisting of micro-megakaryocytes as well as giant forms with highly segmented nuclei (four nuclear lobes), which gave the cells a pleomorphic appearance. As compared with the normal bone marrow, the amount of neutrophilic granulopoiesis and erythropoiesis was not significantly increased in PTH, in contrast to P. vera. Similar results were obtainable regarding the density of reticulin (argyrophilic) fibers: a normal content was encountered in the control specimens and PTH, whereas P. vera displayed a minimal-to-slight increase. Finally, the bone marrow of P. vera was totally devoid of stainable iron while hemosiderin deposits were detected in about two-thirds of the patients without hematologic disorders and in PTH. The characteristic differences revealed by this morphometric study may lead to an improvement of the controversial histologic diagnosis in these disorders.     

Reactive thrombocytosis alone does not affect the patency of microvascular anastomosis in the splenectomy rat

Vascular thrombosis is a harbinger of failure in microsurgery. However, there is still controversy regarding the correlation of the complications of thrombocytosis and thrombosis. Some evidence indicates that patients with elevated platelet counts tend to have a higher flap failure rate, and surgeons usually hesitate to operate on patients with thrombocytosis. Nevertheless, the authors have experienced successful free tissue transfer in seven patients with thrombocytosis resulting from traumatic splenectomy or multiple trauma. On the basis of clinical observation, the authors investigated whether reactive thrombocytosis contributes to the patency of a microvascular anastomosis. In a rodent splenectomy-induced thrombocytosis model (n = 40), stable reactive thrombocytosis occurred after postoperative days 5 to 10, with the peak on postoperative day 7. Femoral artery division and reanastomosis was performed in rats with or without splenectomy-induced thrombocytosis, and vascular patency was assessed. Platelet counts and platelet activation were studied in correlation to microvascular patency. Platelet activation as demonstrated by CD62P expression on platelets was not significantly different between rats with and without thrombocytosis (6.41 +/- 0.95 percent versus 4.51 +/- 0.55 percent, respectively; p = 0.089). As immature platelets were not increased (2.86 +/- 0.33 percent versus 1.99 +/- 0.32 percent, p = 0.074), it seems that the splenectomy-induced thrombocytosis is the result of redistribution of platelets instead of an increase in bone marrow production. There were no significant differences in the patency rates or perfusion units of femoral artery after arterial anastomosis between rats with and without thrombocytosis (90 percent and 95 percent, respectively; p = 0.561). In conclusion, this study demonstrates that microvascular anastomosis can be performed safely in patients with reactive thrombocytosis without platelet activation.     

JAK2V617F 点突变与骨髓增殖性疾病的临床相关性研究

目的:研究JAK2V617F点突变与骨髓增殖性疾病(myeloproliferative disease,MPD)的临床相关性,为MPD的基因学诊断及靶向治疗提供理论依据。方法:应用等位基因特异性聚合酶链反应(AS-PCR)检测JAK2V617F点突变。结果:102例的MPD患者中包括慢性粒细胞白血病(CML)患者9例、真性红细胞增多症(PV)患者21例、原发性血小板增多症(ET)患者37例、特发性骨髓纤维化(IMF)患者16例和分类不明的骨髓增殖性疾病(uMPD)患者19例,JAK2V617F突变阳性率依次为11%、71.4%、51.4%、75.0%、78.9%。结论:JAK2V617F点突变有助于不同类型MPD的诊断,在MPD疾病的诊断中起重要作用。     

Aggregative behavior and calcium content of platelets in thrombocythemia and thrombocytosis]

Patients with thrombocythaemia due to myeloproliferative disorders (n = 21), with secondary thrombocytosis of various origin (n = 16), and a control group of healthy donors (n = 20) were investigated with respect to the aggregation behaviour and the total calcium content of blood platelets. The calcium content was significantly lower in both groups of patients as compared to controls (2 p less than 0.001). In 16 of 21 patients with myeloproliferative disorders platelet rich plasma did not respond to epinephrine (15 mumol/l), a concentration which induced at least weak aggregation in 14 of 16 patients with secondary thrombocytosis and also in healthy subjects. In patients with thrombocythaemia the mean extent of aggregation induced by epinephrine, collagen or adenosin diphosphate was significantly lower as compared to controls (2 p less than 0.001).     

Splenomegaly in myelofibrosis-new options for therapy and the therapeutic potential of Janus kinase 2 inhibitors

ABSTRACT: Splenomegaly is a common sign of primary myelofibrosis (PMF), post-polycythemia vera myelofibrosis (post-PV MF), and post-essential thrombocythemia myelofibrosis (post-ET MF) that is associated with bothersome symptoms, which have a significant negative impact on patients' quality of life. It may also be present in patients with advanced polycythemia vera (PV) or essential thrombocythemia (ET). Until recently, none of the therapies used to treat MF were particularly effective in reducing splenomegaly. The discovery of an activating Janus kinase 2 (JAK2) activating mutation (JAK2V617F) that is present in almost all patients with PV and in about 50-60?% of patients with ET and PMF led to the initiation of several trials investigating the clinical effectiveness of various JAK2 (or JAK1/JAK2) inhibitors for the treatment of patients with ET, PV, and MF. Some of these trials have documented significant clinical benefit of JAK inhibitors, particularly in terms of regression of splenomegaly. In November 2011, the US Food and Drug Administration approved the use of the JAK1- and JAK2-selective inhibitor ruxolitinib for the treatment of patients with intermediate or high-risk myelofibrosis, including PMF, post-PV MF, and post-ET MF. This review discusses current therapeutic options for splenomegaly associated with primary or secondary MF and the treatment potential of the JAK inhibitors in this setting.     

Severe thrombocytosis and anemia associated with celiac disease in a young female patient: a case report

Introduction

Platelet counts exceeding 1.000 × 10³/μl are usually considered secondary to another cause, particularly to chronic myeloproliferative disease (CMPD). Reactive thrombocytosis due to iron deficiency rarely exceeds platelet counts of 700 × 10³/μl.

Case presentation

Here we report the case of a young woman presenting with clinical signs of severe anemia. Laboratory findings confirmed an iron-deficiency anemia associated with severe thrombocytosis of 1703 × 10³/μl. Macroscopic gastrointestinal and genitourinary tract bleeding was excluded. The excessive elevation of platelets, slightly elevated lactate dehydrogenase and slightly elevated leukocytes along with the absence of other inflammation parameters raised the suspicion of an underlying hematological disease. However, bone marrow evaluation could not prove the suspected diagnosis of a CMPD, especially essential thrombocythemia (ET). In the further clinical course the platelet count returned to normal after raising the hemoglobin to a level close to normal range with erythrocyte transfusion, and normalization of serum iron and decline of erythropoietin. Finally, following small bowel biopsy, despite the absence of typical clinical signs, celiac disease was diagnosed. After discharge from hospital the patient was commenced on a gluten-free diet and her hemoglobin almost completely normalized in the further follow-up period.

Conclusion

This case illustrates the rare constellation of an extreme thrombocytosis most likely secondary to iron deficiency due to celiac disease. This represents, to the best of the authors' knowledge, the highest reported platelet count coincident with iron deficiency. A potential mechanism for the association of iron-deficiency anemia and thrombocytosis is discussed. Even in the presence of 'atypically' high platelets one should consider the possibility of reactive thrombocytosis. Extreme thrombocytosis could emerge in the case of iron deficiency secondary to celiac disease.

     

Oxymetholone treatment in myelofibrosis

In order to study the effect of oxymetholone therapy in advanced myelofibrosis, 11 patients (4 females, 7 males) were given, 3--5 mg per kg body weight, long-term oxymetholone treatment in a prospective multicenter study. Five cases had previously had a diagnosis of polycythemia vera. All patients had anemia initially, 4 leukocytopenia and 10 thrombocytopenia in addition. Hepato-splenomegaly was present in all cases but in varying degree. Five patients required regular blood transfusions before treatment. In 9 of the 15 courses given, there was normalization of the peripheral blood or substantial improvement (better than 3 g hemoglobin/dl or 50 X 10(9) platelets/1) after androgens. Significant effects were noted both on hemoglobin values and platelet counts. The need for blood transfusions ceased completely in all 5 cases. When oxymetholone treatment was reduced or interrupted 4 patients relapsed; 2 of them responded to a renewed course. The red cell counts returned to previous polycythemic values in one patient and another died from acute leukemia. The results of this study suggest that androgens might be of value in advanced cases of myelofibrosis with transfusion-requiring anemia or severe thrombocytopenia.     

Effect of iron therapy on platelet counts in patients with inflammatory bowel disease-associated anemia

Background and Aims

Secondary thrombocytosis is a clinical feature of unknown significance. In inflammatory bowel disease (IBD), thrombocytosis is considered a marker of active disease; however, iron deficiency itself may trigger platelet generation. In this study we tested the effect of iron therapy on platelet counts in patients with IBD-associated anemia.

Methods

Platelet counts were analyzed before and after iron therapy from four prospective clinical trials. Further, changes in hemoglobin, transferrin saturation, ferritin, C-reactive protein, and leukocyte counts, before and after iron therapy were compared. In a subgroup the effect of erythropoietin treatment was tested. The results were confirmed in a large independent cohort (FERGIcor).

Results

A total of 308 patient records were available for the initial analysis. A dose-depended drop in platelet counts (mean 425 G/L to 320 G/L; p<0.001) was found regardless of the type of iron preparation (iron sulphate, iron sucrose, or ferric carboxymaltose). Concomitant erythropoietin therapy as well as parameters of inflammation (leukocyte counts, C-reactive protein) had no effect on the change in platelet counts. This effect of iron therapy on platelets was confirmed in the FERGIcor study cohort (n=448, mean platelet counts before iron therapy: 383 G/L, after: 310 G/L, p<0.001).

Conclusion

Iron therapy normalizes elevated platelet counts in patients with IBD-associated anemia. Thus, iron deficiency is an important pathogenetic mechanism of secondary thrombocytosis in IBD.     

Standardization of bone marrow features--does it work in hematopathology for histological discrimination of different disease patterns?

Standardized bone marrow (BM) features determined by semiquantitative scoring are valuable tools for the recognition and easily reproducible interpretation of histological patterns in hematopathology. This procedure may help to characterize various disease entities, but especially to differentiate chronic myeloproliferative disorders (MPDs) with increased platelet counts from reactive thrombocytosis (RTh). A clear-cut separation of these conditions continues to present a major problem in hematology. Therefore MPDs are a most suitable model to test the diagnostic relevance of this procedure. By regarding the literature and based on archive material that involved BM biopsies of 319 patients, a semiquantitative grading of histological parameters was performed. Standardized features were applied for a stepwise discriminant analysis to establish different sets of variables exerting a diagnostic impact. A distinction into five histological patterns was achieved that showed a correctly predicted group membership of about 94 %. These were consistent with the clinicopathological diagnosis of polycythemia vera, essential thrombocythemia (ET), prefibrotic or early fibrotic chronic idiopathic myelofibrosis (CIMF) and finally RTh. Variables of discriminating potency according to their ranking included megakaryopoiesis (maturation defects, nuclear lobulation, naked and bulbous nuclei, small and giant size), reticulin fibers, erythro- and granulopoiesis (left shifting and quantity) and cellularity. These findings are in keeping with the assumption that characteristic patterns of BM histopathology can be assigned to different subtypes of MDPs mimicking ET. Discrimination between ET and especially early stage CIMF with thrombocythemia is warranted because of significant implications concerning therapeutic strategies, follow-up examinations and survival. Regarding these results, a schematic procedure is proposed to be used for daily routine diagnosis concerning the discrimination of MPDs.     

Platelet factor 4 release induced by intravenous administration of heparin

When heparin is injected intravenously, it can induce an immediate release of platelet factor 4 PF4), probably from the non-platelet pool of endothelial cells. We evaluated this release in a group of normal subjects and patients with cardiovascular disorders or thrombocytosis after an intravenous injection of a bolus of 5,000 I.U. of a commercial mucous heparin. The mean level in normals was 102 +/- 32 (range 50-160) ng/ml and no correlation was found before and after heparin injection between PF4 and heparin level, body weight or platelet count. Only three cardiovascular patients had an elevated level of PF4 released by heparin (HR-PF4) that could be the expression of an increased platelet turnover, whereas all the patients with thrombocytosis had an extremely elevated level of HR-PF4. These patients have much more PF4 available for the binding sites of endothelial cells since only a small percentage of potential binding sites are normally occupied "in vivo". Although no correlation could be found between platelet count and HR-PF4 in subjects with a normal platelet count or in patients with thrombocytosis there was a positive correlation, however, when all the cases were considered together. The other proteins with heparin affinity, B-thromboglobulin, antithrombin III and fibronectin were not influenced by a bolus of heparin and did not correlate in normals as well in patients with HR-PF4.     

High Resolution Melting Analysis: A Rapid and Accurate Method to Detect CALR Mutations

Background

The recent discovery of CALR mutations in essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients without JAK2/MPL mutations has emerged as a relevant finding for the molecular diagnosis of these myeloproliferative neoplasms (MPN). We tested the feasibility of high-resolution melting (HRM) as a screening method for rapid detection of CALR mutations.

Methods

CALR was studied in wild-type JAK2/MPL patients including 34 ET, 21 persistent thrombocytosis suggestive of MPN and 98 suspected secondary thrombocytosis. CALR mutation analysis was performed through HRM and Sanger sequencing. We compared clinical features of CALR-mutated versus 45 JAK2/MPL-mutated subjects in ET.

Results

Nineteen samples showed distinct HRM patterns from wild-type. Of them, 18 were mutations and one a polymorphism as confirmed by direct sequencing. CALR mutations were present in 44% of ET (15/34), 14% of persistent thrombocytosis suggestive of MPN (3/21) and none of the secondary thrombocytosis (0/98). Of the 18 mutants, 9 were 52 bp deletions, 8 were 5 bp insertions and other was a complex mutation with insertion/deletion. No mutations were found after sequencing analysis of 45 samples displaying wild-type HRM curves. HRM technique was reproducible, no false positive or negative were detected and the limit of detection was of 3%.

Conclusions

This study establishes a sensitive, reliable and rapid HRM method to screen for the presence of CALR mutations.     

alpha-Interferon in hematological malignancies.

Recent studies have generated data demonstrating significant clinical activity of alpha-interferon therapy in each of six hematological malignancies, chronic myeloid leukaemia, essential thrombocythemia, polycythemia rubra vera, non-Hodgkin's lymphomas, multiple myelomatosis and hairy cell leukaemia.     

Monoclonal gammopathy in chronic myeloproliferative disorders

The incidence of monoclonal gammopathy in 61 patients with chronic myeloproliferative disorders (CMPD) was studied. The distribution of patients among the CMPD subgroups was: chronic myelocytic leukemia, 24 patients; myelofibrosis, 11; polycythemia vera, 15; essential thrombocythemia, 7; unclassified MPD, 4 patients. Monoclonal gammopathy was found in 5 patients (8.2%). Two of these patients (1 IgA/k and 1 IgM/k) had myelofibrosis and 3 (2 IgG/k and 1 IgG/lambda) polycythemia vera. The presence of monoclonal gammopathy indicates an involvement of the lymphoplasmatic system in CMPD.