[Amyloidosis in sub-Saharan Africa]

Amyloidosis is a protein folding disorder in which normally soluble proteins are deposited extracellularly as insoluble fibrils. When stained with Congo red dye, it produces apple-green birefringence under polarized light. The main amyloid proteins are AL, AA, ATTR and Aβ(2)-M. The incidence of amyloidosis in sub-Saharan Africa ranges from 0.28 to 0.57% in autopsy series. Secondary AA amyloidosis is the most frequent, found in 42 to 66% of amyloidoses. Chronic infections, especially tuberculosis, are the main cause. AL amyloidosis is found in 21 to 34% of amyloidosis cases, half of them due to myeloma. Other types of amyloidosis seem rare, but are probably underdiagnosed. The clinical presentation in sub-Saharan Africa is similar to that in Western series. Further experimental and clinical studies will allow a better assessment of the characteristics of amyloidosis in sub-Saharan Africa.