A blinded study of bone marrow examinations in patients with primary immune thrombocytopenia

Reference guide for the diagnosis of adult primary immune thrombocytopenia, 2023 edition

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia due to accelerated platelet destruction and impaired platelet production. Diagnosis of ITP is still challenging because ITP has been diagnosed by exclusion. Exclusion of thrombocytopenia due to bone marrow failure is especially important in Japan because of high prevalence of aplastic anemia compared to Western countries. Hence, we propose a new diagnostic criteria involving the measurement of plasma thrombopoietin (TPO) levels and percentage of immature platelet fraction (RP% or IPF%); 1) isolated thrombocytopenia with no morphological evidence of dysplasia in any blood cell type in a blood smear, 2) normal or slightly increased plasma TPO level (< cutoff), 3) elevated RP% or IPF% (> upper limit of normal), and 4) absence of other conditions that potentially cause thrombocytopenia including secondary ITP. A diagnosis of ITP is made if conditions 1-4 are all met. Cases in which criterion 2 or 3 is not met or unavailable are defined as "possible ITP," and diagnosis of ITP can be made mainly by typical clinical course. These new criteria enable us to clearly differentiate ITP from aplastic anemia and other forms of hypoplastic thrombocytopenia and can be highly useful in clinical practice for avoiding unnecessary bone marrow examination as well as for appropriate selection of treatments.

Immune attack on megakaryocytes in immune thrombocytopenia

A State of the Art lecture titled "Immune Attack on Megakaryocytes in ITP: The Role of Megakaryocyte Impairment" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. Immune thrombocytopenia (ITP) is an acquired autoimmune disorder caused by autoantibodies against platelet surface glycoproteins that provoke increased clearance of circulating platelets, leading to reduced platelet number. However, there is also evidence of a direct effect of antiplatelet autoantibodies on bone marrow megakaryocytes. Indeed, immunologic cells responsible for autoantibody production reside in the bone marrow; megakaryocytes progressively express during their maturation the same glycoproteins against which ITP autoantibodies are directed, and platelet autoantibodies have been detected in the bone marrow of patients with ITP. In vitro studies using ITP sera or monoclonal antibodies against platelet and megakaryocyte surface glycoproteins have shown an impairment of many steps of megakaryopoiesis and thrombopoiesis, such as megakaryocyte differentiation and maturation, migration from the osteoblastic to the vascular niche, adhesion to extracellular matrix proteins, and proplatelet formation, resulting in impaired and ectopic platelet production in the bone marrow and diminished platelet release in the bloodstream. Moreover, cytotoxic T cells may target bone marrow megakaryocytes, resulting in megakaryocyte destruction. Altogether, these findings suggest that antiplatelet autoantibodies and cellular immunity against bone marrow megakaryocytes may significantly contribute to thrombocytopenia in some patients with ITP. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress. The complete unraveling of the mechanisms of immune attack-induced impairment of megakaryopoiesis and thrombopoiesis may open the way to new therapeutic approaches.

Current approaches for the diagnosis and management of immune thrombocytopenia

Immune thrombocytopenia (ITP), is an acquired autoimmune disorder characterized by the destruction of platelets and megakaryocytes, resulting in thrombocytopenia (platelet count <100 × 10⁹/L). This review focuses on the diagnosis and current management of ITP. The diagnosis of ITP is based principally on the exclusion of other causes of isolated thrombocytopenia using patient history, physical examination, blood count, and evaluation of the peripheral blood film. The clinical treatment goals should be to resolve bleeding events and to prevent severe bleeding episodes. The platelet count should be improved to attain a minimum of > 20-30 × 10⁹/L. Therapy should be given as an inpatient in newly diagnosed ITP with a platelet count of > 20 × 10⁹/L or if there is active bleeding. Corticosteroids are considered the standard initial treatment for newly diagnosed patients. Subsequent medical therapies with robust evidence include thrombopoietin receptor agonists (TPO-RAs), rituximab and fostamatinib. Surgical therapy with splenectomy may be considered for patients failing medical therapy. The choice between therapy options is highly dependent upon patient values and preferences.

ASSOCIATION OF SOME IMMUNOLOGICAL BIOMARKERS WITH RHEUMATOID ARTHRITIS PATIENTS IN THI-QAR PROVINCE

OBJECTIVE

The aim: The aim of this research is to evaluate some immunological biomarkers in cases of Rheumatoid arthritis and to verify their correlation with activity of disease among the population of Thi-Qar province.

PATIENTS AND METHODS

Matherials and methods: This study included 45 cases of rheumatoid arthritis and 45 healthy subjects. All cases underwent complete history taking, thor¬ough clinical examination, and laboratory tests including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Anti-citrulline antibody (Anti-CCP) and rheumatoid factor (RF). IL-17and TNF-α blood level was measured by Enzyme Linked Immunosorbent Assay (ELISA) method. DAS-28 (Disease activity score 28) was evaluated.

RESULTS

Results: Serum levels TNF-α was higher in Rheumatoid arthritis patients (424.3±19.46 pg/ml) than in healthy individuals (112.7±4.73 pg/ml), and IL-17 blood levels were higher in Rheumatoid arthritis patients (233.5±241.4 pg/ml) than the healthy individuals group (47.24±49.7 pg/ml). There was significant association found among IL-17, DAS-28, CRP and hemoglobin levels.

CONCLUSION

Conclusions: In conclusion, IL-17 blood levels were significantly increased in peoples with rheumatoid arthritis than in healthy individuals. Its significant relationship with DAS-28 suggested that the level of IL-17 in serum could be important immunological biomarker for activity of disease in disease of Rheumatoid arthritis.

Frequency and utility of bone marrow examination in relapsed/refractory immune thrombocytopenia

BACKGROUND

The diagnosis of immune thrombocytopenia (ITP) is one of exclusion. Although guidelines recommend against routine bone marrow examination (BME) at time of ITP diagnosis, the role of BME in relapsed/refractory ITP is unclear.

OBJECTIVES

To examine the frequency and predictors of BME in relapsed/refractory ITP.

PATIENTS/METHODS

This multicenter retrospective cohort study included adults with ITP who received second-line therapy in Alberta, Canada from 2012 to 2019. We calculated the frequency of BME and rate of abnormal marrow findings. Logistic regression was performed to assess predictors of BME and predictors of bone marrow pathology.

RESULTS

Of 324 patients with presumed ITP, 181 (56%) underwent BME. We observed a marked decline in the rates of BME among patients >60 years over the past decade, but not in patients younger than age 60 years. On multivariable logistic regression, older age (adjusted OR [aOR] 1.03, p = .0001), anemia (aOR 2.5, p = .01), splenomegaly (aOR 3.2, p = .01), splenectomy (aOR 2.4, p = .02), and lack of splenectomy response (aOR 3.4, p = .04) were significant predictors of BME. Abnormal marrow findings were found in eight (2% of overall cohort; 4% of BME): four myelodysplastic syndrome, one aplastic anemia, one chronic lymphocytic leukemia, one metastatic cancer, and one megaloblastic anemia. Seven (88%) underwent BME for bicytopenias/pancytopenias. Macrocytosis (aOR 9.6, p = .03) and rural residence (aOR 6.7, p = .02) were independent predictors of abnormal bone marrow findings.

CONCLUSIONS

Although routine BME is frequently performed in relapsed/refractory ITP, abnormal findings are rare. Future prospective studies are needed to help identify a subgroup of relapsed/refractory ITP who may benefit from BME.

Impact of reticulin stain in clinical outcome of Immune Thrombocytopenic Purpura (ITP): a pathologist perspective

Background

This study evaluated histopathological characteristics of bone marrow (BM) of patients with immune thrombocytopenic purpura (ITP) and sought to find possible associations among them and clinical aspects.

Method

A retrospective study was carried out with 120 patients using BM clot and BM biopsy samples, including morphological (cytological and histological) re-evaluation, reticulin and hemosiderin analysis, and clinical outcome review of medical records. Immunohistochemistry (CD34 and CD117) was applied in a group of patients with increased reticulin, with the objective of exclusion Myelodysplastic syndrome cases

Results

Megakaryocytic hyperplasia was observed in 109 (90.8%) patients and increased reticulin was diagnosed in nine patients, five of them with a clinically unfavorable outcome (p = 0.042). The increase in reticulin graduation was associated with a higher risk of an unfavorable outcome.

Conclusion

Increased reticulin degree in BM of patients with ITP is associated with an unfavorable outcome in this study. It is rarely explored in the literature and may provide information that contributes to understanding the patient's outcomes.

Erratum: Ultrastructural alterations of megakaryocytes in thrombocytopenia: A review of 43 cases

Thrombocytopenia is a frequent occurrence in a variety of hematopoietic diseases; however, the details of the mechanism leading to low platelet count remain elusive. Megakaryocytes are a series of progenitor cells responsible for the production of platelets. Alterations in megakaryocytes in the bone marrow are a causative factor resulting in thrombocytopenia in varied diseases. Based on ultrastructural analysis of incidentally encountered megakaryocytes in 43 patients with blood diseases marked by low platelet counts, electron micrographs demonstrated that aberrant megakaryocytes predominated in idiopathic thrombocytopenic purpura, aplastic anemia, and myelodysplastic syndrome; autophagy, apoptosis, and cellular damage in megakaryocytes were a prominent feature in aplastic anemia. On the other hand, poorly differentiated megakaryocytes predominated in acute megakaryoblastic leukemia (AMKL) although damaged megakaryocytes were seen in non-AMKL acute leukemia. This paper documents the ultrastructural alterations of megakaryocytes associated with thrombocytopenia and reveals distinctive features for particular blood diseases. A comment is made on future avenues of research emphasizing membrane fusion proteins.

Comparative study of IgG binding to megakaryocytes in immune and myelodysplastic thrombocytopenic patients

Immune thrombocytopenia (ITP) is a disorder in which autoantibodies are responsible for destruction and decreased production of platelets. In the meantime, thrombocytopenia is frequent in patients with myelodysplastic syndromes (MDS) and immune clearance of megakaryocytes could be a reason. The aim of the present study is to evaluate and compare IgG binding to megakaryocytes in bone marrow of ITP and MDS patients to determine megakaryocytes targeting by autoantibodies in vivo as a mechanism of platelet underproduction in these disorders. The study was carried out on 20 ITP (group I) patients, 20 thrombocytopenic patients with (MDS) (group II), and 20 non-ITP patients as a control (group III) who were admitted to Minia University Hospital. Serial histological sections from bone marrow biopsies were stained for IgG. All patients in group I and 50% of group II patients showed bleeding tendency and the difference was significant (p < 0.001). No patient experienced fatigue in group I while 35% of patients in group II complained of easy fatigability, and the difference was significant (p < 0.008). High IgG antibody binding was found in ITP and MDS compared to the control group but no significant difference between ITP and MDS patients (14/20 (70%) vs. 13/20 (65%)) (p value = 0.736). Antibody binding to megakaryocytes in a proportion of MDS patients suggests that immune-mediated mechanism underlies platelet underproduction in those patients.

Dysregulated megakaryocyte distribution associated with nestin+ mesenchymal stem cells in immune thrombocytopenia

Impaired megakaryocyte (MK) maturation and reduced platelet production are important causes of immune thrombocytopenia (ITP). However, MK distribution and bone marrow (BM) niche alteration in ITP are unclear. To investigate the maturation and distribution of MKs in the BM niche and examine the components of BM niche regulation of MK migration, BM and peripheral blood were obtained from 30 ITP patients and 28 healthy donors. Nestin⁺ mesenchymal stem cells (MSCs) and CD41⁺ MKs were sorted by fluorescence-activated cell sorting. The components of the BM niche and related signaling were analyzed via immunofluorescence, flow cytometry, enzyme-linked immunosorbent assay, reverse transcription polymerase chain reaction, and western blot analysis. The number of MKs in the BM vascular niche was reduced in ITP. Moreover, the concentrations of CXCL12 and CXCR4⁺ MKs in the BM were decreased in ITP. Further investigation demonstrated that nestin⁺ MSCs and CXCL12 messenger RNA (mRNA) in nestin⁺ MSCs were both reduced whereas the apoptosis of nestin⁺ MSCs was significantly increased in ITP. Sympathetic nerves, Schwann cells, the proportion of β3-adrenoreceptor (β3-AR)⁺ nestin⁺ MSCs, and β3-AR mRNA in nestin⁺ MSCs were all markedly reduced in ITP. Moreover, matrix metalloproteinase 9, vascular endothelial growth factor (VEGF), and VEGF receptor 1 were significantly reduced in ITP. Our data show that impaired MK distribution mediated by an abnormal CXCL12/CXCR4 axis is partially involved in reduced platelet production in ITP. Moreover, sympathetic neuropathy and nestin⁺ MSC apoptosis may have an effect on the alterations of BM CXCL12 in ITP.

Protective Effect of Royal Jelly against Cyclophosphamide-Induced Thrombocytopenia and Spleen and Bone Marrow Damages in Rats

Objective

Despite the effective role of chemotherapy in cancer treatment, several side effects have been reported to date. For instance, Cyclophosphamide (CP) induces deleterious effects on both cancer and normal cells. Royal jelly (RJ) has a lot of beneficial properties, such as anti-oxidant and anti-inflammatory activities. The aim of the present study was to examine the protective effect of RJ against CP-induced thrombocytopenia, as well as bone marrow, spleen, and testicular damages in rats.

Materials and Methods

In this experimental study, 48 male Wistar rats were divided into six groups (n=8/group); control, CP, RJ (100 mg/kg), RJ (200 mg/kg), RJ (100 mg/kg)+CP, and RJ (200 mg/kg)+CP groups. RJ was administered orally for 14 days. Then, CP at concentrations of 100, 50, and 50 mg/kg was intraperitoneally injected at day 15, 16, 17, respectively. The animals were sacrificed three days after the last injection of CP. Hematological parameters, serum levels of platelet factor 4 (PF4), nitric oxide (NO), and ferric reducing antioxidant power (FRAP) were measured. Also, the pathological analysis of bone marrow, spleen, and testicles was assessed.

Results

CP caused a significant decrease in the number of platelets, white and red blood cells (P<0.001), as well as the levels of FRAP (P<0.01), whereas the serum levels of PF4 and NO were significantly increased. These detrimental alterations were significantly reversed to the baseline upon pretreatment of rats with RJ in the RJ100+CP and RJ200+CP groups (P<0.05). CP caused histological changes in bone marrow, spleen, and testes. Pretreatment with RJ showed noticeable protection against these harmful effects.

Conclusion

RJ prevented CP-induced biochemical and histological damages.

Flow cytometry and immune thrombocytopenic purpura

Although Immune thrombocytopenic purpura is a common disorder that family physicians, internists and hematologists face in their everyday practice, its diagnosis rests only on "exclusion" and its therapy is based on algorithms where "trial and error" is the rule. Flow cytometry, if simplified and standardized, could provide a quicker and better diagnostic accuracy. Studies of the lymphocyte subset using flow cytometry and more elaborate immune studies are paving the way for a better understanding of the disease and in identification of prognostic markers. Such studies may even help stratify the first-line therapy responder and assist in the use of the arsenal of immune suppressive therapy with better precision.

Thrombocytopenia

Thrombocytopenia is a commonly encountered hematologic problem in inpatient and ambulatory medicine. The many underlying mechanisms of thrombocytopenia include pseudothrombocytopenia, splenic sequestration, and marrow underproduction and destruction. This article presents the known causes of thrombocytopenia, a framework for evaluation, and brief descriptions of management in a case-based format.

Antibody binding to megakaryocytes in vivo in patients with immune thrombocytopenia

OBJECTIVES

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder caused by increased platelet destruction and impaired platelet production. Antibody binding to megakaryocytes may occur in ITP, but in vivo evidence of this phenomenon is lacking.

METHODS

We determined the proportion of megakaryocytes bound with immunoglobulin G (IgG) in bone marrow samples from primary patients with ITP (n = 17), normal controls (n = 13) and thrombocytopenic patients with myelodysplastic syndrome (MDS; n = 10). Serial histological sections from archived bone marrow biopsies were stained for CD61 and IgG. IgG binding and the number of bone marrow megakaryocytes were determined morphologically by a hematopathologist with four assessors after a calibration exercise to ensure consistency.

RESULTS

The proportion of ITP patients with high IgG binding (>50% of bone marrow megakaryocytes) was increased compared with normal controls [12/17 (71%) vs. 3/13 (23%), P = 0.03]. However, the proportion of ITP patients with high IgG binding was no different than thrombocytopenic patients with MDS [12/17 (71%) vs. 7/10 (70%), P = 1.00]. IgG binding was associated with increased megakaryocyte numbers. Like platelet-associated IgG, megakaryocyte-associated IgG is related to thrombocytopenia but may not be specific for ITP.

CONCLUSION

Mechanistic studies in ITP should focus on antibody specificity and include thrombocytopenic control patients.

Serum Thrombopoietin and cMpl Expression in Thrombocytopenia of Different Etiologies

The relationship between thrombopoietin (TPO) and its receptor cMpl in thrombocytopenic conditions has not been entirely clarified. To elucidate this interplay may expand the spectrum of indications of TPO mimetics. In this study we have explored the relationship between TPO and cMpl in platelets and megakaryocytes of 43 patients with thrombocytopenia due to idiopathic thrombocytopenic purpura (ITP), bone marrow hypoplasia, myelodysplastic syndromes (MDS), and familial thrombocytopenia. Data were compared to cMpl and TPO in patients with a normal platelet count and in patients with thrombocytosis due to essential thrombocythemia (ET). All but familial patients showed higher TPO compared to controls. All thrombocytopenic states were invariably associated with increased expression of platelet cMPL compared to healthy controls. ET patients showed normal TPO and a trend toward a reduced cMpl expression. Immunofluorescence of bone marrow sections from patients with ITP and MDS failed to show a peculiar pattern compared to controls. Multiple mechanisms regulate TPO and cMpl in thrombocytopenic conditions.

Current management of immune thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune-mediated condition that results from antibody-mediated destruction of platelets and impaired megakaryocyte platelet production. ITP patients exhibit severe thrombocytopenia and are at risk for significant hemorrhage. Few randomized trials exist to guide management of patients with ITP. Ultimately, each patient requires an individualized treatment plan that takes into consideration the platelet count, bleeding symptoms, health-related quality of life, and medication side effects. This article provides an up-to-date review of management strategies drawing on links between the expanding amounts of clinical trial data and associated biology studies to enhance understanding of the disease heterogeneity with regard to the complex pathogenesis and response to treatment.