Thrombocytopenia and Platelet Dysfunction in Acute Tropical Infectious Diseases

Abstract

Thrombocytopenia is a well-known manifestation of acute tropical infectious diseases. The role of platelets in infections has received much attention recently because of their emerging activities in modulation of inflammatory responses, host defense, and vascular integrity. However, while many studies have addressed thrombocytopenia in tropical infections, abnormalities in platelet function have been largely overlooked. This is an important research gap, as platelet dysfunction may contribute to the bleeding tendency that characterizes some tropical infections. The development of novel platelet function assays that can be used in thrombocytopenic conditions (e.g., flow cytometry assays) has contributed to important new insights in recent years. In this review, the importance of platelets in tropical infections is discussed with special emphasis on the underlying mechanisms and consequences of thrombocytopenia and platelet dysfunction in these infections. Special attention is paid to malaria, a disease characterized by microvascular obstruction in which bleeding is rare, and to infections in which bleeding is common, such as dengue, other viral hemorrhagic fevers, and the bacterial infection leptospirosis. Given the importance of platelet function abnormalities in these infections, the development of affordable assays for monitoring of platelet function in low-resource countries, as well as pharmacologic interventions to prevent or reverse platelet function abnormalities, might improve clinical care and the prognosis of these infections.

COVID-19 in Pregnancy: Implication on Platelets and Blood Indices

“…16,17 Thrombocytopenia secondary to COVID-19 showed a better outcome compared to the outcomes of other more life-threatening viral infections, such as sever cases of influenza, dengue fever, and SARS-CoV-1 infection. [17][18][19][20] Still, it is unclear whether COVID-19 alters the function of the platelets. 20 We verified significant differences between cases and controls regarding platelet parameters in the current study, with the possibility that they play a role in the raised risk of developing thrombosis, which is in line with the findings of the study by Manne et al 15 The platelet indices in reaction to viral infections were previously assessed in patients with dengue fever in Sudan.…”

Viral-Induced Inflammatory Coagulation Disorders: Preparing for Another Epidemic

“…In contrast, thrombocytopenia and platelet dysfunction that relate to bleeding and plasma leakage are frequently observed in viral hemorrhagic fever. Thrombocytopenia is the result of activation and aggregation in response to the infection [92]. In Dengue fever, neither VWF antigen nor activity is high, platelet-VWF binding correlated with platelet count [93].…”

“…In comparison to thrombocytopenia, abnormalities in platelet function have been largely overlooked. However, it is important to consider that platelet dysfunction also contributes to the bleeding tendency that characterizes viral hemorrhagic fever [92].…”

Point-of-care thrombocyte function testing using multiple-electrode aggregometry in dengue patients: an explorative study

“…Excellent studies have explored the role of thrombocytes in viral infections [ 12 – 14 ]. Thrombocytes not only play a crucial role in primary haemostasis, they are also known to play an important role in inflammatory responses, host defense and vascular integrity [ 15 , 16 ].…”