The haematology of homozygous sickle-cell disease - abstract

ABSTRACT

The purpose of the study was to investigate age- and sex-related variations in the haematology of older patients with SS disease, in order to determine haematological characteristics possibly favouring survival. Steady state haematology was available in 181 patients aged 40-73 years. There appeared to be no consistent sex differences in any of the indices examined. Longitudinal analyses were performed for the 133 patients with at least two observations, using analysis of covariance (ANCOVA) methods. Highly significant declines in total haemoglobin (Hb), platelet counts and absolute reticulocyte count were displayed in both sexes. Overall, Hb levels decreased by approximately 0.076 gm/dl/year in females and 0.113 gm/dl/year in males. Significant increases occurred in HbA, HbF and MCV in females only. The total nucleated count (NBC) fell with age, although the decline was only significant in females. These observations are consistent with a progressive bone marrow failure which is not explained by the commonly occurring renal impairment in older SS patients since the changes persisted in analyses confined to the 84 patients with normal creatinine levels (C=120 æmol/l). The mechanism for this bone marrow failure is currently unknown. The prevalence of homozygous alpha thalassaemia in the study group (4.4 percent) was similar to that in the overall SS population, providing no evidence that this may lead to improved survival, as has been suggested (AU)