Serological and immunological investigations in patients with gross splenomegaly from the Gabon.

Serological investigations (immunoglobulin, haptoglobin, cryoglobulin, and antibody determination against Plasmodium falciparum and P. malariae antigens) were performed in 64 adults of the Albert-Schweitzer-Hospital, Lambarene, Gabon. The patients were referred consecutively for ultrasound examination of the upper abdominal tract. 31 patients had clinically and sonographically an enlarged spleen, whereas 34 had a normal-sized spleen. 18 patients were regarded as having a gross splenomegaly without an obvious underlying cause (tropical splenomegaly (TSS]. No significant differences were seen between the patient groups with regard to immunoglobulin M or antiplasmodial antibody concentration. Thus, a causal association of splenomegaly with chronic malaria infections could not be established. The haptoglobin levels were significantly (P less than 0.01) reduced in patients with splenomegaly. Peripheral T-lymphocyte subsets as defined by monoclonal antibodies showed in all 4 cases with gross splenomegaly examined distinct abnormalities. Tropical splenomegaly is thought to encompass a variety of diseases, most of them presenting an intermediate stage of reactive to autonome disorders of the lymphatic system.