Progress And Challenges In Africa At The Time Of Molecular Haematology

Abstract

The study of blood diseases has been traditionally at the border between clinical medicine and laboratory science. Many of us have been attracted to haematology by this combination: by the very fact that from examining a patient and looking at the blood picture it is often possible to make a diagnosis. As for understanding the nature of any disease, there are several layers: but since the middle of the last century, when the phrase ‘molecular disease’ was coined to aptly describe the basis of sickle cell anaemia,1 it became clear that in understanding the causes and the pathogenetic mechanisms of any disease the ultimate layer must be molecular.

From the middle of the last century African pioneers of haematology have been prominent: without detracting from others, let me mention Alex Boyo in Nigeria,2 Felix Konotey-Ahulu in Ghana,3 Edward Kasili in Kenya,4 Aloysius Nhonoli in Tanzania,5 Charles Olweny in Uganda6: as I have been fortunate to know each one of them in person. As clinical and epidemiological studies were being conducted, the pattern of blood disorders in sub-Saharan Africa (SSA) gradually emerged, and it had several important features. First, as could be expected, an African patient with megaloblastic anaemia, or one with thrombocytopenic purpura, or one with Hodgkin disease, or one with any other specific blood disease was not much different from a patient with the same disease in any other part of the world. Second, in contrast to clinical similarity, the prevalence of many blood conditions was very different: first and foremost, anaemia was and still is rampant,7 due to a variety of infectious and nutritional causes, and it is of great clinical importance particularly in children and in pregnancy.8 Third, whereas in USA and in Europe haemoglobinopathies are officially ‘rare diseases’, in many countries in SSA the prevalence of sickle cell disease (SCD) at birth is from 1 to 2%: with millions of people affected, it is a major public health problem. Fourth, a unique haematologic malignancy, Burkitt’s lymphoma, was discovered in Africa.9 Last, in SSA, and especially in West Africa, endemic malaria, in addition to being a major cause of mortality in children, is always in the background: during my first couple of years at UCH in Ibadan, when I regarded myself as being still very much in training, I learnt that when a patient had a fever the question was not whether he or she had malaria: rather, whether it was just malaria or also something else on top.