Platelet function in preleukaemia

A Critical Reappraisal of the Bleeding Time

Seminars in Thrombosis and Hemostasis (STH) celebrates 50 years of publishing in 2024. To celebrate this landmark event, STH is republishing some archival material. This manuscript represents the second most highly cited paper ever published in STH. The manuscript published without an abstract, and essentially represented a State of the Art Review on the bleeding time, a relatively invasive procedure that required an incision on the skin or earlobe of a patient, and timing how long it took for the incision to stop bleeding. The bleeding time test was first described in 1901 by the French physician Milian, who presented three studies of bleeding from stab wounds made in the fingertips of healthy and diseased subjects. In 1910, Duke observed the duration of bleeding from small incisions of the ear lobe, and pointed out that the duration of bleeding was increased in instances of reduced platelet counts. The test was subsequently repeatedly modified, and numerous variants of the test, including semiautomated methods, were described by several workers. The most frequently utilised test reflected one described by Ivy and coworkers, who shifted the location of the incision to the volar aspect of the forearm and applied a blood pressure cuff to the arm to maintain a standard venous pressure. The bleeding time has been proposed for use as a diagnostic test for platelet-related bleeding disorders, a measure of efficacy in various forms of therapy, and as a prognosticator of abnormal bleeding. The authors to the current review reevaluated the bleeding time literature using methods to assess the performance of the test in 1990, locating 862 printed documents that discussed the bleeding time, the majority in peer-reviewed professional journals. As this is a republication of archival material, transformed into a modern format, we apologise in advance for any errors introduced during this transformation.

Safety and efficacy of romiplostim in patients with lower-risk myelodysplastic syndrome and thrombocytopenia

PURPOSE

To assess the safety and efficacy of romiplostim, a peptibody that increases platelet production, for treatment of thrombocytopenic patients with myelodysplastic syndromes (MDS).

PATIENTS AND METHODS

Eligible patients had lower-risk MDS (International Prognostic Scoring System low or intermediate 1), a mean baseline platelet count <or= 50 x 10(9)/L, and were only receiving supportive care. Patients received three injections of 300, 700, 1,000, or 1,500 microg romiplostim at weekly intervals. After evaluation of platelet response at week 4, patients could continue to receive romiplostim in a treatment extension phase for up to 1 year.

RESULTS

All 44 patients who enrolled completed the treatment phase; 41 patients continued into the extension phase. Median platelet counts increased throughout the study, from fewer than 30 x 10(9)/L at baseline to 60, 73, 38, and 58 x 10(9)/L at week 4 for the 300-, 700-, 1,000-, and 1,500 -microg dose cohorts, respectively. A durable platelet response (per International Working Group 2000 criteria for 8 consecutive weeks independent of platelet transfusions) was achieved by 19 patients (46%). The incidence of bleeding events and platelet transfusions was less common among patients who achieved a durable platelet response than those who did not (4.3 v 39.3 per 100 patient-weeks). Forty-three patients (98%) reported one or more adverse events. Treatment-related serious adverse events were reported in five patients (11%), all of whom were in the 1,500-microg dose cohort. Two patients progressed to acute myeloid leukemia during the study. No neutralizing antibodies to either romiplostim or endogenous thrombopoietin were seen.

CONCLUSION

Romiplostim appeared well-tolerated in this study and may be a useful treatment for patients with MDS and thrombocytopenia.

The incidence and impact of thrombocytopenia in myelodysplastic syndromes

Thrombocytopenia and platelet dysfunction contribute to hemorrhagic complications in the myelodysplastic syndromes (MDS). Reliable data regarding the frequency and consequences of thrombocytopenia in MDS are lacking. An extensive literature review indicated that the prevalence of thrombocytopenia (platelets<100x10(9)/L) in MDS ranged from 40% to 65%; the median frequency of thrombocytopenia prior to any MDS therapy was 65% (range, 23-93%). A retrospective review of patients who were referred to the University of Texas M. D. Anderson Cancer Center (MDACC) identified 1605 of 2410 patients (67%) with thrombocytopenia at referral. Of these, 1756 patients were classified using the International Prognostic Scoring System (IPSS), and 896 patients (51%) had intermediate-2 or high-risk disease. Treatment-related thrombocytopenia was observed in studies that involved azacitidine, tipifarnib, decitabine, lenalidomide, sirolimus, and combination chemotherapy with idarubicin, cytarabine, and topotecan. The reported incidence of hemorrhagic complications in the literature ranged from 3% to 53%, and the frequency of hemorrhagic deaths ranged from 14% to 24%. At MDACC, 460 patients had a coded cause of death: hemorrhage as a contributory cause of death, 20%; hemorrhage as the only cause of death, 10%. Thrombocytopenia was common in MDS, and there was an increased prevalence in higher risk IPSS categories. Many approved and investigational MDS therapies caused or exacerbated preexisting thrombocytopenia. The incidence of severe bleeding in MDS was greater than reported in current guidelines.

Post-splenectomy thrombocytopenia: implications for regional analgesia

Hospital computerised records were reviewed to identify patients who had undergone splenectomy, then chart their platelet count before and for the 5 days after the operation. A pre-operative platelet count less than 100 x 10(9).l-1 occurred in 66% of leukaemia (n = 35), 56% of lymphoma (n = 41) and 5% of solid tumour (n = 39) patients. Platelet supplementation prior to epidural catheter insertion may reduce the risks of spinal bleeding. However, accidental catheter removal during a postoperative period of thrombocytopenia may lead to formation of an epidural haematoma. The lowest postoperative platelet count was less than 100 x 10(9).l-1 in 66% of leukaemia, 27% of lymphoma and 13% of solid tumour patients. Platelet counts varied considerably, so predicting an individual patient's postoperative nadir from the pre-operative count would be impossible. Consequently, placement of an epidural catheter in many of these patients could expose them to an increased risk of spinal bleeding if the catheter is removed accidentally.

Defective megakaryocytic development in myelodysplastic syndromes

Megakaryocytic proliferation and differentiation is typically abnormal in patients with myelodysplastic syndromes (MDS). The underlying mechanisms for this finding are not known, but may involve defects at the level of the thrombopoietin-receptor (c-mpl) or post-receptor signaling pathways in megakaryocyte progenitor cells. Premature apoptosis of the bone marrow cells and inhibitory effects of cytokines such as tumor necrosis factor alpha have been implicated as contributing to altered megakaryopoiesis in MDS, but their significance remains unclear. The availability of thrombopoietin (TPO) has facilitated more detailed analysis of megakaryocytic biology using several experimental in-vitro systems. However numerous studies have shown that the developmental abnormalities of MDS megakaryocytes could not be corrected by TPO. Increasing investigations are being extended to the evaluation of signal transduction pathways of c-mpl both in cell lines and human hematopoietic cells in order to identify the molecular mechanisms responsible for the defective megakaryocytic development in MDS.

Platelet dysfunction as the presenting feature of atypical myelodysplastic syndrome with monosomy 7, normal blood counts and no bleeding tendency

A 71-year-old male patient with atypical myelodysplastic syndrome showing monosomy 7 is described. He presented with severe foot pains, trophic skin and nail changes, loss of distal pulses, all compatible with peripheral arterial occlusive disease. He had completely normal blood counts and no bleeding tendency. Prolonged bleeding time was disclosed by chance, during routine haemostatic studies. An acquired platelet dysfunction was considered, with prolonged bleeding time and large platelets that failed to aggregate in response to arachidonic acid and that had impaired response to collagen and adrenaline. The bone marrow was hypercellular, with numerous dysplastic megakaryocytes and two other slightly dysplastic myeloid lines. Cytogenetic analyses of the bone marrow cells showed a mosaic karyotype: 46,XY/45,XY,-7. On angiography, bilateral thrombosis of the iliac, superficial femoral and popliteal was disclosed. The patient was prepared with platelet transfusions. Arterial thrombectomy and amputation of the left calf were performed. Ten months later, his blood counts showed mild pancytopenia. He died at home. The authors discuss some clinical and pathogenetical aspects of such presentations of myelodysplastic syndromes.

Myelodysplastic syndromes. Pathogenesis, diagnosis and treatment

Our understanding of the biology of leukemia and myelodysplasia is still only partial. The diagnosis of myelodysplasia is often based on quantitative and qualitative findings in the peripheral blood and bone marrow. These findings are often shared by other disorders. There is a need for sensitive and inexpensive laboratory tests to determine clonality and karyotypic abnormalities in this disorder. Future classifications of these syndromes will need to be based on morphologic and biologic markers that are closely linked to disease progression, response to treatment, and survival. Our limited understanding of the pathogenesis of MDS decreases the specificity and effectiveness of our therapeutic interventions. Agents that are minimally toxic such as CRA, danazol, 1,25-dihydroxyvitamin D3, androgens, and pyridoxine are seldom useful. Antileukemic therapy and allogeneic bone marrow transplantation have a major role to play in patients younger than 45 years of age; in older patients these treatment modalities remain controversial because of their toxicity. Hematopoietic growth factors, used alone or in combination, may improve the quality of life and improve survival of patients with MDS. Growth factors may also decrease treatment-related mortality associated with chemotherapy and bone marrow transplantation and render these treatment modalities available for a higher percentage of patients. The development of more specific differentiating agents may permit hematopoietic differentiation while minimizing side effects.

Complications and treatment of the myelodysplastic syndromes

The major complications of the myelodysplastic syndromes (MDS) are related to cytopenia and evolution to acute myeloid leukemia (AML). Hematopoietic growth factors are only of limited benefit to alleviate the cytopenia. Therapy in MDS patients over the age of 50 should aim at prolonging survival while limiting the risk of toxicity. Those with stable disease should only receive supportive care; those with progressive cytopenia should have a trial with low-dose chemotherapy. Aggressive chemotherapy should only be reserved for those failing low-dose therapy. Therapy in MDS patients under the age of 50 should aim at cure of the disease. Although aggressive chemotherapy can induce complete remission in the majority of these patients, remission is usually short. Allogeneic bone marrow transplantation is probably the only curative option in these patients and should be the treatment of choice.

Chronic pure thrombocytopenia in elderly patients. An aspect of the myelodysplastic syndrome

From a group of 276 elderly patients studied in the last 12 years in a department of nuclear medicine for investigating a chronic thrombocytopenia, 36 patients have an acquired disorder, with normal platelet life span, a normal megakaryocytic bone marrow count, and absence of any evident cause at the time of clinical evaluation. During the 2 to 10 subsequent years, 16 patients developed symptoms of the myelodysplastic syndrome, i.e., chronic aregenerative anemia, granulocytopenia, dysmyelopoiesis, and appearance of circulating blast cells; three of them died from acute myeloblastic leukemia. So a pure thrombocytopenia due to a platelet production defect, without any demonstrated functional platelet defect or morphologic dysmegakaryocytosis, may be a preleukemic syndrome. In the other 20 patients, with the same pure chronic thrombocytopenia, no malignant evolution has been seen with long follow-up delays, which is often also the case in pure refractory anemias. In the absence of objective criteria of a possible premalignant disorder, the classification of these cases is difficult, which it is also the case for the so-called refractory anemias. We suggest to individualize, in the classification of the myelodysplastic syndromes, a group of pure refractory thrombocytopenias. From a practical point of view such a diagnosis may be useful, at least to avoid inefficient and possibly harmful treatments.

Myelofibrosis in primary myelodysplastic syndromes: a clinico-morphological study of 10 cases

We describe 10 cases of primary myelodysplastic syndrome in which marrow fibrosis was striking at presentation. All the cases showed trilineage dysplasia with increased megakaryopoiesis and marked reticulin fibrosis. Significant organomegaly was notably absent. This association has hitherto not been highlighted and it is important to distinguish these cases from those of idiopathic myelofibrosis with which they may be confused. Furthermore, their comparatively long survival distinguishes these cases from those previously described as acute myelodysplasia with myelofibrosis and malignant myelosclerosis. The pathogenesis of fibrosis in these cases may be related to disordered megakaryopoiesis and the platelet-derived cytokines that may be released. The treatment of these fibrotic cases remains problematical and further investigation is required.

Haematopoietic and immunologic abnormalities in severe aplastic anaemia patients treated with anti-thymocyte globulin

Thirty-five patients with severe aplastic anaemia (SAA) were extensively evaluated 0.3-12.4 years (median 3.8) after anti-thymocyte globulin (ATG) treatment. All but one were transfusion independent. Most patients revealed a normal Hb level and a granulocyte count over 1.5 x 10(9)/l but were still thrombocytopenic due to decreased platelet production. Lymphocytopenia and/or monocytopenia was found in about 30%. Two patients had a monocytosis. Although there was a great range in degree of recovery at various time intervals after ATG, patients tested more than 4 years after ATG tended to have higher cell counts. Lymphocyte counts correlated with the interval between ATG and evaluation, and with haematopoietic recovery. Qualitative abnormalities were found in all cell lines. Most patients showed a homogeneous macrocytic RBC population, and almost 50% a positive sucrose lysis test; only three patients showed evidence of haemolysis and only two of these showed a positive Ham test. Mean platelet volumes were reduced out of proportion to their number. Platelet function, determined by bleeding time and aggregometry, was impaired in over 30%. The granulocytic series showed a shift to the left in about 30%. Hypersegmentation and pseudo Pelger-Huet anomaly were seen in some patients. Lymphocyte subset distribution in blood and bone marrow was within the normal range but absolute blood levels of CD4 cells in particular were slightly decreased, and tended to increase gradually with time after ATG. IgG and IgA levels were significantly decreased. In only one patient cytogenetic analysis of unstimulated bone marrow cells revealed an abnormal karyotype, but in eight of eight patients an increased sensitivity of lymphocytes to X-rays was found. These data suggest impairment at the level of the very early haematopoietic progenitor cell in all patients up to 10 years after ATG. Since similar findings have been reported in clonal (pre-)malignant disease, SAA, improved after ATG treatment, might be prone to clonal (malignant) evolution.

Delayed maturation of skin window macrophages in myelodysplastic syndromes

Blood monocyte differentiation to macrophages was examined in nine patients with primary myelodysplastic syndromes using the skin window technique. Emigrated cells were stained cytochemically for acid phosphatase reaction after 1, 2, 4, 7, 9, 12 and 23 h. Compared to age-matched controls, seven patients showed a significant delay in lysosomal enzyme acquisition, which is associated with macrophage differentiation. Our results with this in-vivo assay demonstrate an involvement of the monocyte/macrophage system in primary myelodysplastic syndromes and show that patients often have a disturbance in macrophage differentiation.

Biology of myelodysplastic syndromes

Myelodysplastic syndromes (MDS) represent a diverse spectrum of disorders ranging from refractory anemia to a preleukemic state. Peripheral cytopenias, cellular marrow, dysplasias and dysfunctions of myeloid and lymphoid cells constitute hematological hallmarks, and are caused by ineffective hemopoiesis. Investigations of cell cultures and cellular functions indicate that the disease originates in a stem cell pluripotent to all myeloid cells and possibly lymphoid cells as well. The disease commonly runs a chronic indolent course, often terminating in acute leukemia or nonleukemic death, notably infections and/or hemorrhage due to cytopenias and cellular dysfunctions. Clonal expansion or clonal evolution appears to be related to the disease progression with a greater degree of malignancy. However, the initial sequence of events causing damage to stem cells is still undefined.

The myelodysplastic syndromes

The myelodysplastic syndromes constitute a fascinating model for monoclonal premalignant disorders. Haemopoiesis is 'dysplastic' with inefficient maturation of a slowly expanding or sometimes of a stable population, of blood cell precursors. About one third of the patients evolve into acute leukaemia, the result of either a progressive expansion of the original clone or a new mutation producing a more malignant subclone. The majority of patients suffer from the results of bone-marrow insufficiency, with pancytopenia and possibly immune deficiency. Characteristic karyotype anomalies involving mainly chromosomes 5, 7 and 8 are seen in half the patients. These same chromosomes are known to carry different oncogenes. The myelodysplastic syndrome occurs mainly in the aged and there is a moderate male preponderance. The incidence is still unknown but is probably similar to that of acute leukaemia. The etiology is also unknown; however, a secondary myelodysplastic syndrome precedes acute myeloid leukaemia, as a late consequence of chemo- and radio-therapy in treated Hodgkin's disease. This suggests that environmental mutagens might also be involved in primary myelodysplastic syndromes. Treatment remains highly unsatisfactory but a few recent developments improve prognosis, at least in the younger patient.

Thrombocytopenia with thrombocytopathy possibly related to abnormalities of intracellular Ca++ fluxes and followed by the development of leukaemia

A patient is described who presented a thrombocytopenia with thrombocytopathy followed by the development of a leukaemia. The disorder was characterized by decreased aggregation in the presence of ADP, and a lack of aggregation in the presence of arachidonic acid, natural endoperoxide or collagen. In parallel, 14C-serotonin release was severely decreased or nil in response to these inducers. Thrombin induced a slightly decreased aggregation and a normal 14C-serotonin release. Thromboxane B2 (T X B2) synthesis was normal after stimulation by arachidonic acid, natural endoperoxide or thrombin showing a normal arachidonate metabolism. In addition, the mepacrine test showed no significant decrease of the number of dense bodies with an average of 4.6 per platelet (versus 5.4 +/- 0.8 sd in controls). Stimulation by ionophore A 23187 failed to induce aggregation, 14C-serotonin release, or T X B2 synthesis. Furthermore, in the presence of EDTA, A 23187 did not provoke activation as reflected by 14C-serotonin release or T X B2 synthesis. Thus, in this case of thrombocytopathy, the hypothesis of abnormal intracellular Ca++ fluxes responsible for the defective platelet release phenomenon, was suggested.

Myelodysplastic syndromes: pathogenesis, functional abnormalities, and clinical implications

The myelodysplastic syndromes represent a preleukaemic state in which a clonal abnormality of haemopoietic stem cell is characterised by a variety of phenotypic manifestations with varying degrees of ineffective haemopoiesis. This state probably develops as a sequence of events in which the earliest stages may be difficult to detect by conventional pathological techniques. The process is characterised by genetic changes leading to abnormal control of cell proliferation and differentiation. Expansion of an abnormal clone may be related to independence from normal growth factors, insensitivity to normal inhibitory factors, suppression of normal clonal growth, or changes in the immunological or nutritional condition of the host. The haematological picture is of peripheral blood cytopenias: a cellular bone marrow, and functional abnormalities of erythroid, myeloid, and megakaryocytic cells. In most cases marrow cells have an abnormal DNA content, often with disturbances of the cell cycle: an abnormal karyotype is common in premalignant clones. Growth abnormalities of erythroid or granulocyte-macrophage progenitors are common in marrow cultures, and lineage specific surface membrane markers indicate aberrations of differentiation. Progression of the disorder may occur through clonal expansion or through clonal evolution with a greater degree of malignancy. Current attempts to influence abnormal growth and differentiation have had only limited success. Clinical recognition of the syndrome depends on an acute awareness of the signs combined with the identification of clonal and functional abnormalities.

The myelodysplastic syndromes--a study of haemostatic function and platelet ultrastructure

The myelodysplastic syndromes (MDS) are characterised by dysplastic marrow and cytopenia. Clinically detectable bleeding is uncommon and usually attributed to thrombocytopenia. We have investigated some aspects of haemostatic function in 17 patients with MDS and compared the results with findings from 17 control patients matched for age and sex. No specific disorder of blood coagulation or fibrinolysis was identified. The main abnormalities observed in the patients were: prolongation of the bleeding time which was greater than could be explained on the basis of thrombocytopenia in 13 patients; absent, or severely impaired platelet aggregation in response to collagen in 7 patients; impaired platelet production of malondialydehyde when stimulated with collagen and abnormal release of 14C-5 hydroxytryptamine in 5 patients; and abnormalities of ultrastructure in all 5 patients whose platelets were viewed by electron microscopy.

Acute nonlymphocytic leukemia, preleukemia, and acute myeloproliferative syndrome secondary to treatment of other malignant diseases. II. Bone marrow cytology, cytogenetics, results of HLA typing, response to antileukemic chemotherapy, and survival in a total series of 55 patients

Secondary acute nonlymphocytic leukemia or its earlier stages, preleukemia or an acute myeloproliferative syndrome with refractory cytopenia and clonal cytogenetic abnormalities of the bone marrow, was diagnosed in 55 patients previously treated for other malignant diseases. In patients with overt leukemia, cytologic, and cytochemical studies showed predominance of the French-American-British (FAB) type M2. Cytogenetic examination demonstrated a normal karyotype in 11 cases, whereas clonal abnormalities were observed in 44 patients. Defects of chromosome 7 were observed in 24 cases, most often -7, and defects of chromosome 5 in 14 cases, most often 5q-. In addition, chromosomes 3 and 17 were possibly nonrandomly involved. Other abnormalities commonly observed in de novo acute nonlymphocytic leukemia as t(8;21) and t(15;17) were not observed and +8 rarely seen in secondary leukemia. The survival from the leukemic complication was short for the whole group of 55 patients (median, 7 months). However, a significantly longer survival was observed in a subgroup of 11 patients with a normal karyotype (P less than 0.01), due to a favorable response to antileukemic chemotherapy, and in a subgroup of 11 patients with -7 or -C as the only cytogenetic abnormality (P less than 0.01), due to a prolonged preleukemic phase, compared with the remaining 33 cases with mostly multiple karyotypic abnormalities. Three preleukemic patients with -7 who were studied during transformation to overt leukemia all developed additional cytogenetic abnormalities. According to the two-step or multistep hypothesis for malignant transformation, the prolonged preleukemic course in patients with -7 as the only abnormality could represent a premalignant stage, in which further evolution is required for development of overt leukemia. The patients showed a random distribution of blood groups and HLA types.

Prolonged bleeding time

The bleeding time is the most frequently used test of platelet function. This review of the literature relating to the bleeding time outlines the causes and management of prolonged bleeding time. The bleeding time appears to have its greatest utility in evaluation of a patient with active bleeding or one with a well-documented bleeding history. It should not be used as a substitute for a clinical history, since there is insufficient information available to calculate its sensitivity, specificity, or predictive value with regard to peri- or postoperative hemorrhage.

Blood neutrophil function in primary myelodysplastic syndromes

Ten different tests of blood neutrophil function were studied in 20 patients with primary myelodysplastic syndromes (PMDS). The patients were selected according to the new diagnostic criteria for PMDS of the FAB-cooperation group. Impairments of granulocyte functions were found in all patients. Moreover, several steps in the mobilization of granulocytes at the site of injury seemed to be affected: decreased adhesion (P less than 0.05), deficient chemotaxis (P less than 0.05), decreased enzyme content (P less than 0.001), 'slower' chemiluminescence (P less than 0.005), decreased phagocytosis (P less than 0.05) and impaired microbicidal capacity (P less than 0.025). No significant correlation between disease category and severity of granulocyte dysfunction was discerned, though an increasing number of blasts was associated with more severe granulocytic disability. Results in seven patients with abnormal karyotypes were not significantly different from 13 others with normal karyotypes. Our results indicate that defects in blood neutrophil function are a common feature in PMDS and might account for the increased frequency of infection in these patients.

Impaired T-cell and NK-cell function in patients with preleukemia

The responses to the T-cell mitogens Phythemagglutinin (PHA) and Concanavalin A (Con A) and the natural killer (NK) cell activity are tested in patients with preleukemia (PL). The results are compared with those of healthy controls. The PL patients show low responses to T-cell mitogens and low NK cell activities. It is discussed that the data are not of prognostic value in PL as to development of overt leukemia. However, the results suggest that PL impaired cell functions are not limited to erythropoiesis, granulopoiesis, and thrombopoiesis but are also found in the immune system.