Management of sickle cell disease; lessons from the Jamaican Cohort Study.

Sickle cell disease is enormously variable in its expression and outcome. In addition to this intrinsic variability are the problems of symptomatic selection biasing observations towards the severe end of a wide clinical spectrum and a truly changing natural history as a result of better management. Against this background, there was a need for a description of the disease in a truly representative sample of patients and this objective has been approached in the Jamaican Cohort Study of Sickle Cell Disease. Initiated in 1973, this study is based on all cases of sickle cell disease detected among 100,000 consecutive normal deliveries in Kingston, Jamaica. All affected children as well as age matched normal controls have been followed prospectively and are currently aged 11 to 19 years. The following review is based on lessons learnt from this cohort study. It is not intended to be a comprehensive survey of knowledge of sickle cell disease and does not address major contributions from studies elsewhere. In some ways, therefore, the review may appear unbalanced because of this specific objective. However, a great deal has been learnt about the evolution of the abnormal haematology of sickle cell disease and its relationship to clinical features. The causes of early mortality in sickle cell disease in Jamaica are described and the major complications such as acute splenic sequestration, pneumococcal septicaemia, aplastic crisis, hypersplenism, and acute chest syndrome have been addressed with varying success. Overall survival to the age of 19 years has been 75% and it is planned that the study should continue to define the problems of late adolescence and early adult life.