Assessment of Circulating Levels of Platelet Activation Biomarker - Platelet Factor 4 in Sickle Cell Anaemia Patients in Edo State, Nigeria

Aim: To assess the circulating levels of platelet activation biomarker platelet factor 4 in sickle cell anaemia patients attending a sickle cell foundation in Edo State, Nigeria.

Study Design: Case-controlled observational Study.

Place and Duration of Study: Sickle Cell Foundation Benin City, Edo State and Afe Babalola University, Multisystem Hospital, Ado Ekiti, Ekiti State, Nigeria, between April 2020 - September 2020.

Methodology: Thirty (30) Haemoglobin (Hb) SS genotype subjects diagnosed by haemoglobin electrophoresis and aged 10 to 40 years were selected for the study. Twenty-eight (28) Hb AA and 22 Hb AS apparently healthy subjects were used as control. The Hb SS subjects in their steady and crisis states who met the eligibility criteria were used as test subjects and verbal and written consents were obtained from all participants. Venous blood was collected for this study, in which 5ml of the subjects’ venous blood was collected with a syringe, 3ml was put into an Ethylene Diamine Tetra acetic acid container for the evaluation of Platelet count. Platelet indices and the Haemoglobin Genotyping, while 2ml was put into a plain container for the serological assay (Platelet Factor 4 assay), using ELISA method. The platelet count was estimated manually using an improved Neubauer counting chamber and 1% ammonium oxalate, the Haemoglobin Genotype was evaluated manually using an electrophoresis tank and Tris buffer, Platelet indices was evaluated using an Hematology Auto Analyzer. Statistical Package for Social Sciences (SPSS) version 23 was used for statistical analysis and p values less than 0.05 were considered statistically significant.

Results: The results showed no significant difference (p=0.772) and (p=0.878) in the distribution of age and gender respectively on the study participants. The mean serum Platelet Factor 4(PF-4) was significantly increased in the Sickle Cell Disease (SCD) crisis, reduced in the AS and SCD steady groups (p<0.05), compared to the control group. There was also a significantly positive correlation between PF-4 and PDW/MPV (p=0.029 and 0.189 respectively) of SCD steady subjects.

Conclusion: This study serves to prove that the platelet activation biomarker (platelet factor 4) indeed has a significant role and indication in sickle cell anaemia and hence should be put in consideration in laboratory assessment of platelet function in sickle cell disease crisis.