Prognostic factors in myelofibrosis

Revisiting Circulating Extracellular Matrix Fragments as Disease Markers in Myelofibrosis and Related Neoplasms

Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPNs) arise due to acquired somatic driver mutations in stem cells and develop over 10-30 years from the earliest cancer stages (essential thrombocythemia, polycythemia vera) towards the advanced myelofibrosis stage with bone marrow failure. The JAK2V617F mutation is the most prevalent driver mutation. Chronic inflammation is considered to be a major pathogenetic player, both as a trigger of MPN development and as a driver of disease progression. Chronic inflammation in MPNs is characterized by persistent connective tissue remodeling, which leads to organ dysfunction and ultimately, organ failure, due to excessive accumulation of extracellular matrix (ECM). Considering that MPNs are acquired clonal stem cell diseases developing in an inflammatory microenvironment in which the hematopoietic cell populations are progressively replaced by stromal proliferation-"a wound that never heals"-we herein aim to provide a comprehensive review of previous promising research in the field of circulating ECM fragments in the diagnosis, treatment and monitoring of MPNs. We address the rationales and highlight new perspectives for the use of circulating ECM protein fragments as biologically plausible, noninvasive disease markers in the management of MPNs.

The value of bone marrow, liver, and spleen imaging in diagnosis, prognostication, and follow-up monitoring of myeloproliferative neoplasms: a systematic review

Background

Diagnostic and treatment response criteria for the JAK2/CALR/MPL mutation-related myeloproliferative neoplasms (MPNs) are largely based on bone marrow (BM) biopsy results. However, these biopsies have several limitations, such as the risk of sampling error. Also, the prognostic impact of BM abnormalities is largely unclear. Although not currently used in clinical practice, imaging techniques might offer additional information. In this review, we investigated the value of BM, liver, and spleen imaging for diagnosis, prognostication, and response monitoring of the JAK2/CALR/MPL mutation-related MPNs (i.e. essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF)).

Methods

A systematic literature search was performed via PubMed, Embase and the Cochrane Library up to 2020 March 26th. Of 5505 identified records, 55 publications met the eligibility criteria (i.e. containing original data on the imaging appearance of BM, spleen, or liver in adult ET, PV, or MF patients, published in a peer-reviewed journal, written in English).

Results

Many explorative studies described imaging features, sometimes with comparisons to clinical characteristics. Studies reporting measures of diagnostic accuracy included 1) splenic transient elastography to predict BM fibrosis grade in MF, 2) dynamic contrast-enhanced MRI to discern MF patients from ET patients and healthy controls, and 3) 18-fluorodeoxyglucose PET to detect residual disease after stem cell transplantation in MF. The diagnostic accuracies of radiography and ^99mTc-colloid scintigraphy were derived from several other articles. Except for the study on 18-fluorodeoxyglucose PET, we established substantial concerns regarding risk of bias and applicability across these studies, using the QUADAS-2 tool. Three publications described a correlation between imaging results and prognosis, of which one quantified the effect.

Conclusions

Based on current data, MRI (T1-weighted/STIR, Dixon) seems especially promising for the evaluation of BM fat content - and indirectly cellularity/fibrosis - in MF, and possibly for estimating BM cellularity in ET/PV. 18-fluorodeoxyglucose and 18-fluorothymidine PET/CT might be useful for evaluating BM fibrosis, with good reported accuracy of the former for the diagnosis of residual disease. Further research on these and other techniques is warranted to determine their exact value. Future researchers should improve methodology and focus on evaluation of diagnostic accuracy and prognostic implications of results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-021-00405-7.

Current diagnostic criteria for the chronic myeloproliferative disorders (MPD) essential thrombocythemia (ET), polycythemia vera (PV) and chronic idiopathic myelofibrosis (CIMF)

The clinical criteria for the diagnosis of essential thrombocythemia (ET) according to the polycythemia vera study group (PVSG) do not distinguish between ET and thrombocythemia associated with early stage PV and prefibrotic chronic idiopathic myelofibrosis (CIMF). The clinical criteria of the PVSG for the diagnosis of polycythemia vera (PV) only detects advanced stage of PV with increased red cell mass. The bone marrow criteria of the World Health Organization (WHO) are defined by pathologists to explicitly define the pathological criteria for the diagnostic differentiation of ET, PV, and prefibrotic and fibrotic CIMF. As the clinical PVSG and the pathological WHO criteria show significant shortcomings, an updated set of European Clinical and Pathological (ECP) criteria combined with currently available biological and molecular markers are proposed to much better distinct true ET from early PV mimicking ET, to distinguish ET from thrombocythemia associated with prefibrotic CIMF, and to define the various clinical and pathological stages of PV and CIMF that has important therapeutic and prognostic implications. Comparing the finding of clustered giant abnormal megakaryocytes in a representative bone marrow as a diagnostic clue to MPD, the sensitivity for the diagnosis of MPD associated with splanchnic vein thrombosis was 63% for increased red cell mass, 52% for low serum EPO level, 72% for EEC, and 74% for splenomegaly indicating the superiority of bone marrow histopathology to detect masked early and overt MPD in this setting. The majority of PV and about half of the ET patients have spontaneous EEC, low serum EPO levels and PRV-1 over-expression and are JAK2 V617F positive. The positive predictive value for the diagnosis of PV of spontaneous growth of endogenous erythroid colonies (EEC) of peripheral blood (PB) and bone marrow (BM) cells is about 80-85% when either PB or BM EEC assays, and up to 94% when BM and PB EEC assays were performed. The diagnostic impact of low serum EPO levels (ELISA assay) in a large study of 186 patients below the normal range (<3.3 IU/l) had a sensitivity specificity and positive predictive value of 87%, 97% and 97.8%, respectively, for the diagnosis of PV. There is a significant overlap of serum EPO levels in PV versus control and controls versus SE. The specificity of a JAK2 V617F PCR test for the diagnosis of MPD is high (near 100%), but only half of ET and MF (50%) and the majority of PV (up to 97%) are JAK2 V617F positive. The use of biological markers including JAK2 V617 PCR test, serum EPO, PRV-1, EEC, leukocyte alkaline phosphatase score and peripheral blood parameters combined with bone marrow histopathology has a high sensitivity and specificity (almost 100%) to diagnose the early and overt stages of ET, PV and CIMF in JAK2 V617F positive and negative MPDs.

Prognostic factors in idiopathic (primary) osteomyelofibrosis

BACKGROUND

Prognostic variables for idiopathic (primary) osteomyelofibrosis (IMF) are ill-defined because of the lack of large control studies based on uniform diagnostic criteria.

METHODS

A retrospective clinicopathologic study was performed on 250 consecutively recruited patients (115 males and 135 females) with an established diagnosis of IMF. In contrast to previous studies, the current study cohort encompassed the full spectrum of initial to advanced stages of the disease process according to laboratory data and particularly histology. Because of the relatively high patient age on admission (median, 66.5 years), relative survival rates with corresponding life expectancies and disease specific life loss were calculated. Moreover, a classification and regression tree (CART) analysis was performed to segregate the study patients into subgroups with significantly different prognosis.

RESULTS

Analysis of the life expectancy and the proportion of deaths attributable to IMF showed a global reduction in life expectancy of 31%. Further calculation disclosed a consistently greater impact of disease in older patients. Age, hemoglobin level on admission, and leukocyte and thrombocyte counts remained as the most relevant parameters for prognosis in multivariate consideration (CART analysis) and facilitated a clear-cut separation into three risk groups. The life expectancy of low risk patients was approximately 10 times higher than that of high risk patients (22.07 years vs. 2.25 years).

CONCLUSIONS

These results are in keeping with the assumption that features signaling bone marrow insufficiency are associated with a worsening of survival. Generalization, indicated by myeloid metaplasia, can occur at every stage, even in so-called hypercellular phases of IMF. Conversely, myelofibrosis alone is not necessarily predictive of poor survival.

Idiopathic primary osteo-myelofibrosis: a clinico-pathological study on 208 patients with special emphasis on evolution of disease features, differentiation from essential thrombocythemia and variables of prognostic impact

A retrospective clinico-pathological study was performed on 208 consecutively recruited patients (94 males, 114 females, median age 67 years) with idiopathic (primary) osteo-/ myelofibrosis (IMF). According to bone marrow histology (cellularity) as well as extent (semiquantitative grading) and quality (reticulin/collagen) of myelofibrosis, stages of the disease process were determined. At closure of this study (observation time 65 months) 133 patients were dead and 75 alive and median survival was 56 months. The wide spectrum of clinical signs and symptoms and laboratory data on admission was reflected by a corresponding variety of histological features. Significant differences of hematological values could be calculated between patients with or without early reticulin fibrosis (fiber scores 0 and 1) and advanced fibro-osteosclerotic stages (fiber scores 2 and 3). Evolution of disease features was elicited by longitudinal follow-up studies and sequential bone marrow biopsies. Morphometric assessment of fiber density in patients without preceding chemotherapy revealed an unpredictable and varying progression of myelofibrosis associated with alterations of certain laboratory parameters (hemoglobin level, spleensize, thrombocytosis). Differentiation from essential (primary) thrombocythemia (ET) was required in 25 patients who fulfilled the postulated diagnostic criteria. In fact, this group was consistent with hypercellular, early stages of IMF without relevant reticulin fibrosis and an excessively raised platelet count (> or = 1000 x 10(9)/1). Discrimination was only feasible by regarding histology carefully, particularly abnormalities of megakaryopoiesis and follow-up data. Parameters of predictive value indicating a significant loss in life expectancy in comparison with a sex- and age-adjusted normal population included: age (> or = 60 years), hemoglobin levels (< or = 10 g/dl), thrombocyte count (< or = 600 x 10(9)/1) and the presence of myeloblasts and promyelocytes. Statistical analysis disclosed that in the so-called early stages of IMF without relevant myelofibrosis, findings indicative for extramedullary hemopoiesis or generalization of the disease process exerted an unfavourable influence on survival.

Erythropoiesis in primary (idiopathic) osteomyelofibrosis: quantification, PCNA-reactivity, and prognostic impact

In 64 patients with primary (idiopathic) osteomyelofibrosis (OMF), a morphometric analysis has been performed on bone marrow trephine biopsies following sequential double-immunostaining with monoclonal antibodies against proliferating cell nuclear antigen (PCNA) and erythroid precursor cells (glycophorin C). The purpose of this study was to quantify erythropoiesis and its PCNA-staining capacity and, further, to determine the impact of these parameters for the development of anemia and for prognosis. In comparison with a control group (15 patients), a significant reduction in the number of erythro-normoblasts could be demonstrated, associated with an increase in PCNA-labelling. Moreover, significant correlations between the amount of nucleated erythroid marrow cells and degree of anemia (hemoglobin level, hematocrit, erythrocyte count) and survival could be calculated. Adverse relationships were assessed between number of erythroid cells, thrombocyte count, and spleen size, and also argyrophilic (reticulin/collagen) fiber density. These interactions were thought to reflect the biological behaviour of the disease process, i.e., the progression or extent of myeloid metaplasia. Our findings support ferrokinetic studies suggesting erythroid hypoplasia as one of the major causes of anemia in OMF. The remarkable high PCNA-labelling index of the macrocytic-megaloblastoid appearing erythropoiesis is probably caused by an overexpression of this marker protein. A comparative evaluation of Ki-67 antigen immunostaining in splenic tissue (myeloid metaplasia) and of the PCNA-labelling in pernicious anemia lend support to the assumption of an undue prolongation of the S-phase generated by secondary folate (hematinic) deficiency.

Primary myelofibrosis: a detailed statistical analysis of the clinicopathological variables influencing survival

In the present study we analyzed the prognostic significance of several clinical, hematological, and histological parameters recorded at diagnosis in a consecutive series of 72 patients with primary myelofibrosis (PMF). Univariate analysis showed that the most significant indicators of poor survival were the following: age greater than 60, splenomegaly, anemia (hemoglobin > 10 g/dl), leukopenia (WBC < 4 x 10(9)/l or leukocytosis > 14 x 10(9)/l), and any of these histological features: adipose tissue and megakaryocyte reduction, prominent osteoblastic rims along the trabecular bone, presence of peritrabecular megakaryocytes (Mk), absence of normal or giant Mk. The multivariate analysis showed that only the level of hemoglobin and the presence of both normal Mk and fever independently influenced the prognosis. These parameters were used to set up a prognostic scoring system, allowing a feasible prognosis to be made for each patient at the time of diagnosis and identifying those patients in urgent need of new therapeutic approaches.

Idiopathic myelofibrosis--an update with particular reference to clinical aspects and prognosis

Idiopathic myelofibrosis (IMF) is characterized by excessive accumulation of connective tissue in the bone marrow as part of a clinical syndrome which in its classical form is featured by leukoerythroblastic anemia and huge splenomegaly at the time of diagnosis. An acute variant of the disease exists being featured by pancytopenia, nor or minimal splenomegaly and a rapidly fatal clinical course. This review describes the relationship of IMF to other chronic myeloproliferative disorders and highlights current concepts of the pathogenesis of bone marrow fibrosis, implicating the intramedullary release of various growth factors, including platelet-derived growth factor beta. In a subgroup of patients bone marrow fibrosis may develop consequent to autoimmune bone marrow damage. The clinical and laboratory findings in some of the larger series of patients are presented and the reasons for the highly variable clinical presentation and prognosis are critically discussed. It is proposed that studies on prognosis in IMF are based upon simple prognostic staging systems, which should include the Hb-concentration, platelet count, spleen size and the presence/absence of osteomyelosclerosis on X-ray. Using these parameters the patients are easily categorized into three prognostic groups with highly different survival times.

Myelofibrosis in chronic myeloproliferative disorders. Incidence among subtypes according to the Hannover Classification

The distribution and the development of fibrosis were evaluated from bone marrow biopsies of patients with chronic myeloproliferative disorders (CMPD), regarding two groups of patients: (1) 564 with follow-up biopsies over a period of up to twelve years observation time, and (2) 1.787 diagnostic bone marrow biopsies from CMPD patients. Fibrosis was divided into three grades of fiber increase: early myelosclerosis, myelofibrosis, and advanced myelofibrosis. The first group of sequential BMB showed a significant progress to myelofibrosis in so-called "Chronic Megakaryocytic-Granulocytic Myelosis"--CMGM-, which corresponds to Agnogenic Myeloid Metaplasia-AMM-in 72.4% (21/29 patients), as well as in CML with megakaryocytic increase-CML.MI-in 39.2% (20/51). In the second group of diagnostic biopsies, only 30% of CMGM cases showed no fibrosis. In P. vera, 16.2% (18/111) developed myelofibrosis up to twelve years later. This figure was 4.3% (2/46) in Primary Thrombocythemia. Increase of megakaryocytes in CML indicates a high risk for developing fibrosis, combined with reduced life expectancy.

Morphometric analysis of myelofibrosis in agnogenic myeloid metaplasia and chronic myelogenous leukemia

A morphometric analysis of bone marrow biopsy specimens from patients with myelofibrosis was made to determine the amount of lattice fiber and the number of megakaryocytes, to compare the degree of myelofibrosis in primary and secondary myelofibrosis, and to assess the relationship between the morphometric findings and other parameters. Eight patients with agnogenic myeloid metaplasia (AMM) and six with chronic myelogenous leukemia associated with frank myelofibrosis (CML-MF) were studied. When the main clinical, hematological, and laboratory features of both groups of patients were compared, the only significant difference was in the neutrophil alkaline phosphatase score. Morphometric study showed that the amount of lattice fiber and the number of megakaryocytes in AMM were not statistically different from those in CML-MF, and that neither the number of megakaryocytes nor the platelet count correlated with the amount of lattice fiber.

Life expectancy of patients with chronic nonleukemic myeloproliferative disorders

This study determines, within the frame of current therapeutic possibilities, the impact of chronic nonleukemic myeloproliferative disorders on expected survival. The survival data for 1067 patients (454 with polycythemia vera, 247 with essential thrombocythemia, and 366 with idiopathic myelofibrosis) were collected from 38 Spanish institutions. The actuarial survival probability of each group of patients was compared with that of the age-matched and sex-matched control population. The survival of the patients with polycythemia vera and essential thrombocythemia did not differ from that of the control population (P = 0.92 and, 0.22, respectively), whereas the survival of the patients with idiopathic myelofibrosis was strikingly reduced with respect to the control population (P = 0.0000000007). Thus, in terms of survival, current therapeutic procedures may be considered as quite satisfactory in patients with polycythemia vera and essential thrombocythemia. On the other hand, due to poor survival of patients with idiopathic myelofibrosis, new therapeutic approaches for this condition are clearly needed.

Idiopathic myelofibrosis: a clinical study of 80 patients

A series of 122 consecutive patients with bone marrow fibrosis initially referred or categorized as idiopathic myelofibrosis is described. After a clinical and pathological review 14 patients were classified as postpolycythaemic myelofibrosis and 7 patients as a transitional myeloproliferative disorder. In 13 patients a diagnosis of hairy cell leukaemia was made, 3 patients had malignant lymphoma, 2 had malignant histiocytosis, and 1 patient had systemic lupus erythematosus with myelofibrosis. Two patients were excluded for further analysis owing to insufficient data. In the remaining 80 patients a diagnosis of idiopathic myelofibrosis was made. The clinical and laboratory findings in this series of patients are presented and compared to those in previous series. Infectious, cardiovascular, thromboembolic, and haemorrhagic complications were frequent, being recorded in 63%, 50%, 40%, and 33% of the patients, respectively. Various autoimmune phenomena were found in a proportion of the patients, but none had clinical evidence of connective tissue disease. Fifteen patients (19%) had a syndrome of acute myelofibrosis. The diagnostic criteria for this disease entity and its place within the spectrum of myeloproliferative disorders are discussed. In the present series acute myelofibrosis was found to encompass various transitional stages toward the evolution of acute leukaemia. It is proposed that acute or malignant myelofibrosis is considered as an acute variant of idiopathic myelofibrosis. Within this syndrome the acute variant seems to be far more common than previously recognized, which may also explain the marked clinical heterogeneity of the myelofibrosis/osteomyelosclerosis syndrome in this and most previous series.

Myelofibrosis with myeloid metaplasia: clinical and haematological parameters predicting survival in a series of 133 patients

The prognostic value of 12 clinical and haematological parameters, recorded at diagnosis, in myelofibrosis with myeloid metaplasia (MMM) was retrospectively analysed in a consecutive series of 133 patients followed for a minimum of 60 months. Multivariate analysis showed that the following features were associated with a significantly shorter survival: (1) short period of time (less than 13 months) between first symptoms and diagnosis; (2) anaemia (haemoglobin less than 10 g/dl); (3) leucocyte count greater than 12 x 10(9)/l; (4) peripheral blood granulocyte precursors greater than 10%. Age, splenectomy and percentage of peripheral blood metamyelocytes were found significantly to affect survival only from univariate analysis, whereas sex, size of spleen, thrombocytopenia and thrombocytosis were of no prognostic significance. These data suggest that a more intensive chemotherapy might be useful for younger patients with bad prognostic factors at diagnosis.

Prognostic factors in idiopathic myelofibrosis: a simple scoring system with prognostic significance

In a prognostic univariate analysis of a series of 80 patients with idiopathic myelofibrosis the Hb-concentration, the platelet count and osteomyelosclerosis emerged as factors with prognostic significance. A Hb-concentration less than 10 g/dl was associated with a significantly shorter survival than a Hb-concentration greater than or equal to 10 g/dl. A platelet count less than 100 x 10(9)/l also implied a significantly shorter survival. Patients with osteomyelosclerosis on X-ray of the skeleton had a significantly better prognosis as compared to those without osteomyelosclerosis. In a multivariate regression analysis the Hb-concentration consistently emerged as an important prognostic parameter, whereas the platelet count was only of prognostic significance within the first 6 months from diagnosis and the presence of osteomyelosclerosis emerged as a favourable parameter at 3 and 5 years. Based upon the above parameters and spleen size, a prognostic scoring system was designed which categorized the patients into three prognostic groups with highly different survival times (low risk group = 69 months; intermediate risk group = 33 months; high risk group = 4 months).

Bone marrow histopathology in primary myelofibrosis: clinical and haematologic correlations and prognostic evaluation

In 51 patients with primary myelofibrosis the initial bone marrow biopsy findings were evaluated by morphometric methods, correlated with the patients' main clinical and haematologic data and analysed for prognostic significance. The high variability of the marrow features was the most striking finding of the morphologic study. The only remarkable clinico-pathological correlation was that found between the extent of stromal proliferation in the bone marrow and the number of WBC precursors in peripheral blood. Classical bone marrow histologic patterns did not correlate with the main clinical or haematologic data nor did they influence the patients' survival. Finally, collagen fibrosis and abnormal clusters of immature myeloid precursors were the only histologic features showing an unfavourable prognostic significance at the multivariate study.

Myelofibrosis: a review of clinical and pathologic features and treatment

The purpose of this review is to discuss and clarify the current understanding of the pathogenesis, clinical manifestations, and treatment of MF. MF may be either a primary or secondary disorder. It is characterized by an increased deposition of bone marrow collagen, fibronectin, and laminin. Present evidence indicates that MF may be mediated by platelet or megakaryocyte growth factors, decreased prostaglandin mediated stem cell inhibition, immune complex deposition, and both fibroblast and endothelial cell proliferation. Recently acute MF has been recognized to be identical to acute megakaryocytic leukemia. Secondary MF usually responds to appropriate treatment of the underlying disease. Primary MF is usually treated by blood product support, but may be responsive to androgens, splenectomy, splenic irradiation, chemotherapy, or bone marrow ablation with marrow reconstitution.

Agnogenic myeloid metaplasia (AMM)--correlation of bone marrow lesions with laboratory data: a longitudinal clinicopathological study on 114 patients

A clinicopathological study was performed on 114 patients (46 male/68 female, median age 67 years) with the diagnosis of agnogenic myeloid metaplasia (AMM) respectively primary osteo-myelofibrosis which was not preceded by any other or allied subtype of chronic myeloproliferative disorders. On admission patients revealed a striking variability of laboratory data as well as different histopathological features of initial bone marrow biopsies. For this reason discrimination was done into two groups based on bone marrow findings: group I patients (n = 46, 19 male/27 female) showed a hypercellular marrow without or only borderline (n = 24) to slight (n = 22) reticulin fibrosis and group II cases (n = 68, 27 male/41 female) displayed coarse bundles of collagen fibres (n = 18) frequently accompanied by osteosclerosis (n = 50). Statistical analysis of the corresponding initial hematological findings resulted in significant differences. These differences concerned also the complications occurring during the lengthy course of disease, which included a higher incidence of pancytopenia and severe marrow failure with hemorrhage and blast crisis in group II patients. However, overall survival time was not different in both groups. This may be related to the similarity of age distribution (64 resp. 65 years) and its significant association with arteriosclerotic vascular lesions. Consequently acute myocardial infarction and congestive heart failure were frequent causes of death in addition to infections due to marrow failure and blast crisis. Repeated bone marrow biopsies in 24 patients revealed an insidious transition from hypercellular lesions (group I) into advanced fibro-osteosclerotic changes (group II) concurring with laboratory data. Therefore our discrimination into two groups of patients represents variable stages or static histological and corresponding hematologic features in the evolution of a dynamic disease process in AMM.

A prognostic classification of myelofibrosis with myeloid metaplasia

The dependence of survival time on a set of prognostic factors was explored by means of Cox's regression model in 137 cases of myelofibrosis with myeloid metaplasia (MMM). The following parameters recorded at diagnosis proved to be important independent indicators of a poor prognosis: a higher value for age, a lower value for Hb concentration, a higher value for immature myeloid cells in peripheral blood (IMC), a lower value for total erythroid iron turnover (TEIT), and a bone marrow red cell aplasia (RCA). A prognostic classification tree was constructed whose terminal nodes (risk groups), described by simple logical conditions upon important indicators, were characterized by significantly different expected survival. The two extreme risk groups lend themselves to a simple, but complete description. The low-risk group (19.7% of the sample) comprises cases who had the diagnosis of MMM before age 45 and a number of IMC constantly lower than 24%. The actuarial proportion of patients surviving at 15 years was 100%. The high-risk group (29.9% of cases) comprises patients with age greater than 45 and Hb lower than 13 g/dl, associated with RCA, or with a relatively decreased erythropoiesis (TEIT lower than 2 times the normal) or with IMC greater than 24%. Seven out of the 11 who died within this group developed blastic crisis. Median survival time of the group was 69 months.

Platelet aggregation in platelet rich plasma and whole blood in 18 patients affected by idiopathic myelofibrosis

Platelet aggregation in whole blood (WB) and in platelet rich plasma (PRP) was studied in 18 consecutive patients affected by idiopathic myelofibrosis (IM). On the basis of WB studies, 22% of patients were classified as normo-aggregating and 22% as hypo-aggregating, while 55% had spontaneous platelet aggregation (SPA). SPA was observed also when platelets from patients were stirred in the presence of normal erythrocytes, while it never occurred when normal platelets were stirred in the presence of red cells from patients. PRP studies revealed that 33% and 66% of patients were, respectively, hypo- and normo-aggregating. The most frequent abnormality in PRP was represented by defective or absent aggregation response to epinephrine.

Myelofibrosis and focal segmental glomerulosclerosis associated with toluene poisoning

A 60-year-old man with long-term exposure to toluene presented with both myelofibrosis and focal segmental glomerulosclerosis. There was also evidence of other toluene-related complications to support the diagnosis of toluene toxicity. The toxic effects of toluene, particularly kidney disorders and haematotoxicity, suggest a relationship between toluene, myelofibrosis and focal segmental glomerulosclerosis.

Platelet function in myeloproliferative disorders: characterization and sequential studies show multiple platelet abnormalities, and change with time

Bleeding and thrombosis are well known major causes of morbidity and mortality in patients with myeloproliferative disorders (MPD) but the relationship between these clinical events and the commonly found platelet function abnormalities have not been established. In this study we performed simultaneous laboratory evaluations in 54 patients with MPD to investigate abnormalities in platelet aggregation and cyclooxygenase activity, the latter by using an in vitro aspirin inhibition test; the studies were repeated in 22 patients 1-27 months later. We have found platelet hyper- and hypofunction co-existing in some patients (9/54), and change of platelet function during the course of the disease (7/22) with platelet hypofunction being the only constant abnormality over time. These results may explain the lack of correlation between the clinical events and the limited assessment of platelet function in the hitherto published studies, and also suggest the need for repeated evaluations to properly assess the relative risk for bleeding and thrombosis.

Effect of chemotherapy on tear drop poikilocytes and other peripheral blood findings in myelofibrosis

A leukoerythroblastic blood picture and tear drop shaped red cells are two characteristic features of myelofibrosis (MF). Following our earlier observation of an increase in the hemoglobin level with chemotherapy, we have now reviewed the pre- and post-treatment peripheral blood smears from 14 patients with MF to assess the effect of treatment on the above mentioned peripheral blood features. Our results suggest that these features are reversible with effective chemotherapy.

Myelofibrosis arising in treated histiocytosis X

Myelofibrosis, or fibrous replacement of hematopoietic bone marrow, is rarely encountered in pediatric patients. An unusual, reversible case arising in the setting of treated histiocytosis X is reported, a previously undescribed association. The clinical, pathologic, radiographic, and scintigraphic characteristics of myelofibrosis are reviewed.

Chemotherapy resolves symptoms and reverses marrow fibrosis in myelofibrosis

12 patients with symptomatic chronic myelofibrosis were treated with either busulphan or 6-thioguanine. Therapy was without significant side effects and resulted in a reduction in the size of liver and spleen and an improvement in well-being in all cases. In 7 patients the Hb value rose and the extent of marrow fibrosis was reduced in the 5 patients in whom bone marrow examination was repeated after treatment. Chemotherapy is an effective and safer alternative to splenectomy in patients with myelofibrosis with symptomatic anaemia, symptomatic splenomegaly or constitutional symptoms such as fever, weight loss and night sweats.