Crisis frequency and associated changes in platelet parameters among steady state sickle cell subjects

Objectives: The management of sickle cell anaemia is geared towards resolving sickling crisis as well as possible prevention of crisis for those in steady state. Crisis frequencies vary from person to person and among populations. Its impact, however, extends to morbidity-associated consequences even in steady state. This study investigated crisis frequency of sickle cell anaemia subjects in relation to their platelet parameters. Methods: Subjects comprised 45 male and female sickle cell anaemia patients attending clinic at University of Calabar Teaching Hospital Calabar, Nigeria and equal number of age and sex-matched control subjects with homozygous adult haemoglobin (HbAA). Platelet parameters were analysed by automation using a SMART-1 Hematology Analyzer. Foetal haemoglobin estimation was performed using a modified Betke's method. Results: The platelet count and plateletcrit of sickle cell anaemia patients were significantly higher compared to control subjects. The mean platelet volume was significantly higher among subjects from 30 years of age compared to younger age groups. Initial increase in crisis frequency brought about depletion in the platelet count and plateletcrit. The plateletcrit stabilised as the mean platelet volume picked up at 4-7 crisis frequency within the preceding one year. Conclusion: Increase in crisis frequency and longer years of living with sickle cell anaemia resulted in higher platelet involvement.