The clinical implications of thrombocytopenia in adults with severe falciparum malaria: a retrospective analysis

Abstract

BackgroundThrombocytopenia is a common finding in adults with severe falciparum malaria, but its clinical and prognostic utility is incompletely defined.MethodsClinical and laboratory data from 647 adults with severe falciparum malaria were analysed retrospectively to determine the relationship between a patient’s platelet count on admission to hospital and their subsequent clinical course.ResultsOn admission, 614 patients (94.9%) were thrombocytopenic (platelet count <150 × 109/L) and 328 (50.7%) had a platelet count <50 × 109/L. The admission platelet count was inversely correlated with parasite biomass (estimated from plasma PfHRP2 concentrations, rs = −0.28, P = 0.003), the degree of microvascular sequestration (measured with orthogonal polarizing spectral imaging, rs = −0.31, P = 0.001) and disease severity (the number of World Health Organization severity criteria satisfied by the patient, rs = −0.21, P <0.001). Platelet counts were lower on admission in the patients who died (median: 30 (interquartile range 22 to 52) × 109/L versus 50 (34 to 78) × 109/L in survivors; P <0.001), but did not predict outcome independently from other established laboratory and clinical prognostic indices. The 39 patients (6%) with profound thrombocytopenia (platelet count <20 × 109/L) were more likely to die (odds ratio: 5.00, 95% confidence interval: 2.56 to 9.75) than patients with higher platelet counts, but these high-risk patients could be identified more rapidly with simple bedside clinical assessment. The admission platelet count did not reliably identify the 50 patients (7.7%) with major bleeding during the study.ConclusionsThrombocytopenia is a marker of disease severity in adults with falciparum malaria, but has limited utility in prognostication, triage and management.

Platelet disturbances correlate with endothelial cell activation in uncomplicated Plasmodium vivax malaria

“…Thrombocytopenia is the most common hematological alteration in malaria, although there is no definitive mechanistic explanation to its occurrence (1, 2). In a retrospective cohort, patients who died from malaria had lower platelet counts in comparison to those with less severe disease (3). Moreover, P. vivax malaria patients with thrombocytopenia showed higher levels of markers of endothelial cell (EC) activation compared to those with normal platelet counts (4) and some grade of platelet activation has been reported during the disease (5).…”

Severe imported malaria in a Serbian referral center

“…The circulating level of tumor necrosis factor-alpha (TNF-alpha) was shown to be a marker of organ failure and, as such, was correlated to malaria severity [8][9][10] . Low thrombocyte counts were also proven to be related to the severity both of vivax and falciparum malaria, although some authors questioned their usefulness for triage and prognostication [11][12][13] . Most studies correlating the platelet counts and TNF-alpha levels to disease severity were conducted in endemic settings [9][10][11][12][13] .…”

“…Low thrombocyte counts were also proven to be related to the severity both of vivax and falciparum malaria, although some authors questioned their usefulness for triage and prognostication [11][12][13] . Most studies correlating the platelet counts and TNF-alpha levels to disease severity were conducted in endemic settings [9][10][11][12][13] .…”

Severe Imported Malaria in a Serbian Referral Center

“…Low thrombocyte counts were also proven to be related to the severity of both vivax and falciparum malaria, although some authors questioned their usefulness for triage and prognostication [11][12][13]. Most studies correlating platelet counts and TNF-alpha levels to disease severity were conducted in endemic settings [9][10][11][12][13].…”

“…Most studies correlating platelet counts and TNF-alpha levels to disease severity were conducted in endemic settings [9][10][11][12][13].…”