Immunoglobulin gene polymerase chain reaction to distinguish hyperreactive malarial splenomegaly from ‘African’ chronic lymphocytic leukaemia and splenic lymphoma

Hyperreactive malarial splenomegaly (HMS) is found in geographical association with B cell lymphoproliferative disorders such as ‘African’ chronic lymphocytic leukaemia (CLL) and splenic lymphoma with villous lymphocytes (SLVL). It is sometimes not easy to make a differential clinical diagnosis between these conditions. We have previously used Southern blotting as a definitive method for the diagnosis of monoclonal lymphoproliferation in these disorders, but this is expensive, lengthy and technically difficult. In the present paper we have compared Southern blotting with polymerase chain reaction (PCR) amplification of the immunoglobulin heavy chain gene. We found an excellent correlation between the 2 methods in demonstrating monoclonal populations of lymphocytes in patients with a clinical diagnosis of CLL or SLVL. We have further demonstrated monoclonality in a patient who could not be classified as CLL or SLVL on clinical criteria alone. In contrast, patients with well defined HMS or with non-B cell proliferations all showed polyclonal rearrangements. We propose that the immunoglobulin gene PCR is a useful tool for the investigation of tropical splenomegaly of uncertain origin.