International Journal of Hematology

International Journal of Hematology | Vol. 2, No. 11, November 2011 | pp. 81–88
DOI: 10.46882/2011/IJH/000023

Review Article

Title: Pathophysiological mechanisms and clinical therapeutic targets in heparin-induced thrombocytopenia

Names of Authors: M. A. Bello¹, O. R. Eze²

Authors’ Affiliations: ¹Department of Haematology, Aminu Kano Teaching Hospital, Kano, Nigeria; ²Department of Pathology, University of Benin, Benin City, Nigeria

Abstract: Heparin-induced thrombocytopenia is a paradoxically prothrombotic immune-mediated drug reaction driven by pathogenic IgG antibodies targeting platelet factor 4-heparin complexes. This review synthesizes current insights into cellular interaction mechanisms, emphasizing antibody-mediated Fc-gamma-RIIa receptor cross-linking on platelets, which triggers rapid microparticle release, thrombin generation, and subsequent endothelial injury. Clinical diagnosis relies on scoring systems like the 4Ts algorithm, supported by functional serotonin release assays or enzyme-linked immunosorbent antibody screening. Management mandates the immediate cessation of all heparin formulations and the initiation of rapid-acting non-heparin anticoagulants. Direct thrombin inhibitors like argatroban and factor Xa inhibitors like fondaparinux achieve systemic anticoagulation without cross-reacting with heparin-induced antibodies. Initiating warfarin is strictly contraindicated during the acute thrombocytopenic phase due to the risk of microvascular thrombosis and skin necrosis from protein C depletion. This review presents structured management pathways to optimize patient selection, minimize systemic bleeding risks, and prevent thrombotic limb loss in intensive care populations.

Keywords: Heparin-induced thrombocytopenia, platelet factor 4, argatroban, thrombosis, anticoagulation

Manuscript Timeline: Received: August 11, 2011; Revised: September 22, 2011; Accepted: October 15, 2011; Published: November 18, 2011

International Journal of Hematology | Vol. 2, No. 2, February 2011 | pp. 9–16
DOI: 10.46882/2011/IJH/000014

Review Article

Title: Current perspectives on the pathophysiology and management of acute chest syndrome in sickle cell disease

Names of Authors: T. M. Ahmed¹, V. I. Nnamdi²

Authors’ Affiliations: ¹Department of Haematology, Aminu Kano Teaching Hospital, Kano, Nigeria; ²Department of Paediatrics, University of Nigeria Teaching Hospital, Enugu, Nigeria

Abstract: Acute chest syndrome remains a leading cause of mortality and intensive care admission among individuals with sickle cell disease. This review integrates contemporary understanding of its complex, multi-factorial pathophysiology, which involves pulmonary microvascular occlusion, fat embolism from necrotic bone marrow, and secondary atypical infectious pathogens. High-affinity hemoglobin interactions, endothelial selectin upregulation, and free plasma hemoglobin from intravascular hemolysis drive pulmonary inflammatory cascades. Management paradigms emphasize early identification using bedside pulse oximetry and rapid initiation of empiric broad-spectrum antibiotics, including macrolides. Incentive spirometry reduces pulmonary splinting and prevents atelectasis progression. For severe cases characterized by worsening hypoxemia (PaO₂ < 60 mmHg) or multi-lobar infiltrates, automated erythrocytapheresis is preferred over simple transfusion to rapidly reduce sickle hemoglobin levels below 30% without expanding total blood volume. This review outlines targeted operational protocols to reduce critical care length of stay and improve clinical survival.

Keywords: Sickle cell disease, acute chest syndrome, exchange transfusion, pulmonary inflation, endothelial activation

Manuscript Timeline: Received: November 11, 2010; Revised: December 20, 2010; Accepted: January 08, 2011; Published: February 15, 2011

International Journal of Hematology | Vol. 2, No. 5, May 2011 | pp. 33–40
DOI: 10.46882/2011/IJH/000017

Case Report

Title: Priapism as the Initial Presentation of Hyperleukocytic Acute Myeloid Leukemia: Successful Management with Leukapheresis

Names of Authors: N. R. Danjuma¹, O. B. Nwosu², P. C. Okechukwu³

Authors’ Affiliations: ¹Department of Haematology, Ahmadu Bello University, Zaria, Nigeria; ²Department of Surgery and Urology, University of Nigeria, Nsukka, Nigeria; ³Department of Internal Medicine, Enugu State University of Science and Technology, Enugu, Nigeria

Abstract: Hyperleukocytosis in acute leukemia is a medical emergency that can cause leukostasis, vascular occlusion, and tissue ischemia. We report a unique case of an 24-year-old male who presented with an unprovoked, painful erection lasting 36 hours. A complete blood count revealed a total white blood cell count of 284 × 10⁹/L, with 88% circulating myeloblasts, confirming acute myeloid leukemia (M2 subtype). Peripheral blood smear examination and bone marrow biopsy supported the diagnosis. Hydroxyurea therapy (4 g daily) and aggressive intravenous hydration were initiated immediately. Due to persistent priapism and neurological alterations, a therapeutic leukapheresis procedure was performed, successfully reducing the white blood cell count to 92 × 10⁹/L within 6 hours. Complete detumescence was achieved post-leukapheresis without requiring surgical cavernous shunting. Subsequent standard cytarabine and daunorubicin induction therapy led to complete hematological remission. This case emphasizes hyperleukocytosis as a rare cause of ischemic priapism and demonstrates that prompt leukapheresis is critical for preventing permanent erectile dysfunction and leukostasic complications.

Keywords: Acute myeloid leukemia, hyperleukocytosis, priapism, leukapheresis, leukostasis

Manuscript Timeline: Received: February 15, 2011; Revised: March 24, 2011; Accepted: April 10, 2011; Published: May 16, 2011

International Journal of Hematology | Vol. 2, No. 6, June 2011 | pp. 41–48
DOI: 10.46882/2011/IJH/000018

Original Article

Title: Assessment of platelet storage lesions in random donor platelet concentrates prepared by the platelet-rich plasma method

Names of Authors: Q. S. Bello¹, U. T. Aliyu²

Authors’ Affiliations: ¹Department of Haematology and Blood Transfusion, National Hospital, Abuja, Nigeria; ²Department of Pathology, Bayero University, Kano, Nigeria

Abstract: Platelet storage lesions involve morphological and functional degradation that reduces the therapeutic efficacy of platelet transfusions over time. This study evaluated sequential metabolic and functional changes in 60 random donor platelet units prepared by the platelet-rich plasma method and stored under standard agitation at 22 °C for 7 days. Serial testing at days 1, 3, 5, and 7 measured pH levels, extracellular lactate dehydrogenase, glucose concentrations, and platelet aggregation responses to adenosine diphosphate. Mean bag pH fell significantly from 7.25 ± 0.10 on day 1 to 6.42 ± 0.15 on day 7 (P < 0.05). Extracellular lactate dehydrogenase levels rose by 140% by day 7, indicating progressive platelet lysis. Platelet aggregation efficiency declined from a baseline of 82.4% to 38.6% on day 7. Bacterial contamination screening remained negative in all units. These results show that functional and metabolic degradation increases significantly after 5 days of storage, suggesting that platelet shelf-life should be limited to 5 days to optimize post-transfusion platelet increments.

Keywords: Platelet concentrates, platelet storage lesion, pH, lactate dehydrogenase, platelet aggregation

Manuscript Timeline: Received: March 20, 2011; Revised: April 28, 2011; Accepted: May 12, 2011; Published: June 19, 2011

International Journal of Hematology | Vol. 2, No. 4, April 2011 | pp. 25–32
DOI: 10.46882/2011/IJH/000016

Original Article

Title: Coagulation abnormalities and thrombotic risk factors in patients with nephrotic syndrome

Names of Authors: L. C. Okafor¹, A. T. Solarin², M. D. Alao³

Authors’ Affiliations: ¹Department of Haematology, Lagos State University Teaching Hospital, Ikeja, Nigeria; ²Department of Paediatrics and Nephrology, Lagos University Teaching Hospital, Idi-Araba, Nigeria; ³Department of Medicine, Obafemi Awolowo University, Ile-Ife, Nigeria

Abstract: Nephrotic syndrome establishes a hypercoagulable state due to the urinary loss of low-molecular-weight anticoagulant proteins and concurrent hepatic synthesis of procoagulant factors. This study cross-sectionally evaluated 45 nephrotic patients and 45 healthy controls to quantify plasma levels of antithrombin III, fibrinogen, protein C, and D-dimer. Nephrotic individuals exhibited significantly lower mean antithrombin III levels (54.2 ± 11.6%) compared to controls (98.4 ± 10.2%, P < 0.001). Conversely, plasma fibrinogen concentrations were markedly elevated in the patient cohort (5.80 ± 1.20 g/L versus 2.90 ± 0.50 g/L in controls). Serum albumin levels correlated inversely with D-dimer concentrations (r = -0.62, P < 0.01), where patients with albumin below 20 g/L demonstrated the highest thrombotic risk indices. Deep vein thrombosis occurred in 3 patients (6.6%) during the study window. Routine profiling of antithrombin III and fibrinogen is valuable for identifying nephrotic patients at high risk for thromboembolic complications who may benefit from prophylactic anticoagulation.

Keywords: Nephrotic syndrome, hypercoagulability, antithrombin III, fibrinogen, thromboembolism

Manuscript Timeline: Received: January 10, 2011; Revised: February 18, 2011; Accepted: March 05, 2011; Published: April 12, 2011

International Journal of Hematology | Vol. 2, No. 8, August 2011 | pp. 57–64
DOI: 10.46882/2011/IJH/000020

Original Article

Title: Clinical profile and transfusion requirements of patients with myelodysplastic syndromes

Names of Authors: B. C. Akpan¹, D. E. Ibrahim², F. G. Ojo³

Authors’ Affiliations: ¹Department of Haematology, University of Calabar, Calabar, Nigeria; ²Department of Haematology, Ahmadu Bello University, Zaria, Nigeria; ³Department of Paediatrics, Obafemi Awolowo University, Ile-Ife, Nigeria

Abstract: Myelodysplastic syndromes comprise clonal hematopoietic disorders causing chronic cytopenias and a risk of transformation into acute myeloid leukemia. This study characterized the clinical presentation, hematological features, and transfusion dependency of 54 patients diagnosed with myelodysplastic syndromes using the Revised International Prognostic Scoring System. The median age at presentation was 58 years, with a male-to-female ratio of 1.4:1. Refractory anemia with excess blasts was the most frequent subclassification, occurring in 40.7% of cases. Severe anemia (hemoglobin < 8.0 g/dl) was present in 74.1% of patients at baseline, and 61.1% exhibited chronic erythrocyte transfusion dependency, requiring a mean of 2.4 packed cell units per month. Secondary iron overload, defined by serum ferritin levels above 1000 ng/ml, developed in 37.0% of transfusion-dependent patients after a median of 18 transfusion episodes. This audit highlights a significant disease burden and a high reliance on transfusions among myelodysplastic syndrome cohorts, indicating a clear need for improved access to iron chelation and hypomethylating therapies.

Keywords: Myelodysplastic syndromes, transfusion dependency, ferritin, cytopenia, iron overload

Manuscript Timeline: Received: May 12, 2011; Revised: June 20, 2011; Accepted: July 09, 2011; Published: August 17, 2011