Assessment of platelet indices and platelet activation markers in children with Plasmodium falciparum malaria.

BACKGROUND: Plasmodium falciparum malaria remains one of the world's major infectious diseases that cause most morbidity and mortality, particularly in children. In Ghana, most children below the ages of 5 years depending on the severity of the infection often lose their lives. However, it is still debatable why infection with falciparum malaria contributes to thrombocytopenia. METHODS: This study sought to investigate the expression of the various platelet indices and activation markers in children with falciparum malaria. Platelet indices (Platelet count [PLT], Plateletcrite [PCT], Mean Platelet Volume [MPV], Platelet Distribution Width [PDW] and Platelet-Large Cell Ratio [P-LCR]) and platelet surface membrane glycoproteins (GPIIb/IIIa [PAC-1], P-selectin [CD62p] and GPIV [CD36]) expressions were determined in children with falciparum malaria (cases) and healthy children (controls) using automated blood cell analysis and flow cytometry techniques, respectively. RESULTS: Except for P-LCR, all the other platelet indices (PLT, MPV, PDW, and PCT) were significantly lower in the cases than the controls (P < 0.05). Also, it was observed that the level of expression of the activation markers; PAC 1 and CD62p showed a significant (P < 0.05) decreased before and after activation in falciparum malaria cases than in the controls. On the contrary, CD36 expression in the controls did not differ significantly (p > 0.05) from the malaria cases. Platelet activation markers were known to be associated with increased risk of falciparum malaria with the mean fluorescence intensity of PAC1 (Odds Ratio [OR] 34.0, Relative Risk [RR] 4.47, 95% Confidence Interval [CI] 4.904-235.7; p < 0.0001) and CD36 (OR 4.2, RR 1.82, 95% CI 0.9824-17.96; p = 0.04). Moreover, the percentage expression of CD62p (OR 4.0, RR 1.80, 95% CI 0.59-27.24; p = 0.19) was also observed to be probably associated with increased risk of falciparum malaria although not statistically significant (p > 0.05). CONCLUSION: Plasmodium falciparum malaria has been known to be associated with platelet activation markers, which probably contributes to thrombocytopenia.

Expression of platelet parameters and platelet membrane glycoproteins in childhood Burkitt lymphoma.

Platelet activation and functional changes in some haematological malignancies have been investigated with little or no known documentation on Burkitt lymphoma (BL). Abnormalities of platelets contribute to either haemorrhage or thrombotic episodes which are life-threatening in patients with BL. Thus, the study aimed at investigating the various platelet indices and platelet membrane glycoproteins in childhood Burkitt lymphoma. Platelet surface membrane glycoproteins (GPIIb/IIIa, P-selectin and GPIV using PAC 1, CD62p and CD36 monoclonal antibodies respectively) and platelet indices (Platelet Count [PLT], Plateletcrite [PCT], Mean Platelet Volume [MPV], Platelet Distribution Width [PDW] and Platelet Large Cell Ratio [P-LCR]) were determined in children with Burkitt lymphoma and healthy children (normal controls) based on flow cytometry and automated blood cell analysis techniques. PLT and PCT were higher in BL cases than in the normal controls with a significant difference in the PLT (P = 0.02). On the contrary, we observed a significant (p < 0.05) lower levels in the other platelet indices (MPV, PDW and P-LCR) in children with BL than the controls. With the exception of CD62 P, the other platelet membrane glycoproteins examined showed a decreased level of expression before and after the addition of an Adenosine -5- diphosphate (ADP) in cases of BL. In addition, PAC-1 was probably known to be associated with Burkitt Lymphoma (Odds Ratio [OR] 6.67, Relative Risk [RR] 3.13, 95% CI 1.06-9.21; p = 0.02). Finally, oral bleeding was observed to be the commonest bleeding episodes associated with childhood BL. Flow cytometry analysis and cell counting techniques of platelet assessment has described the expression of the platelet membrane glycoproteins and parameters in children with Burkitt lymphoma. Thus, children with Burkitt lymphoma tend to show normal to increased level of circulatory platelets but decreased platelet membrane glycoprotein expressions and platelet dysfunction.

Determination of Haematological Reference Ranges in Healthy Adults in Three Regions in Ghana.

Laboratory results interpretation for diagnostic accuracy and clinical decision-making in this period of evidence-based medicine requires cut-off values or reference ranges that are reflective of the geographical area where the individual resides. Several studies have shown significant differences between and within populations, emphasizing the need for population-specific reference ranges. This cross-sectional experimental study sought to establish the haematological reference values in apparently healthy individuals in three regions in Ghana. Study sites included Nkenkaasu, Winneba, and Nadowli in the Ashanti, Central, and Upper West regions of Ghana, respectively. A total of 488 healthy participants were recruited using the Clinical and Laboratory Standards Institute (United States National Consensus Committee on Laboratory Standards, NCCLS) Guidance Document C28A2. Medians for haematological parameters were calculated and reference values determined at 2.5th and 97.5th percentiles and compared with Caucasian values adopted by our laboratory as reference ranges and values from other African and Western countries. RBC count, haemoglobin, and haematocrit (HCT) were significantly higher in males compared to females. There were significant intraregional and interregional as well as international variations of haematological reference ranges in the populations studied. We conclude that, for each geographical area, there is a need to establish geography-specific reference ranges if accurate diagnosis and concise clinical decisions are to be made.