VISCERAL LEISHMANIASIS IN SOMALIA - SIGNIFICANCE OF IGG SUBCLASSES AND OF IGE RESPONSE

We have determined the levels of IgG subclasses and IgE as well as spe cific antibodies of these isotypes in sera from 22 patients with clini cal visceral leishmaniasis (VL) from Somalia. The results are compared with those obtained from 30 Somali and 23 Swedish controls. We found markedly increased concentrations of IgG1 in the VL sera, indicating t hat the pronounced increase in IgG in VL which is generally considered to be due to polyclonal B-cell activation is mainly restricted to thi s subclass. The IgG2 concentrations were significantly decreased. The IgG3 and IgG4 concentrations, on the other hand, did not differ betwee n the two groups of Somali sera. The Somali control sera contained hig her concentrations of IgG1 and IgG3, but significantly lower concentra tions of IgG2 as compared to Swedish controls. The IgG4 values, on the other hand, were not different between the two groups of control sera . Anti-leishmania antibodies belonging to all IgG subclasses, were fou nd in the patients' sera. There was no significant difference in total IgE between sera from VL patients and controls and specific IEE antib odies were only detected in a few patients. The Western blot assay (WE ), revealed the presence of two bands corresponding to 74 kDa and 88 k Da in all patients' sera, indicating a possible diagnostic role for WE in this particular population.