Background: The aim of the study was to investigate the possible role of antibodies to Tamm-Horsfall protein (anti-THP) in the early diagnosis of endemic nephropathy (EN).
Methods: Anti-THP (IgA, IgM, IgG classes) antibodies were determined by direct ELISA in a random sample of 159 subjects from the endemic village of Kaniza who were divided into four groups according to the WHO criteria, i.e., 'diseased', 'suspect', 'at risk', and 'others'. These groups were compared to subjects from the non-endemic village of Klakar and healthy subjects from Zagreb.
Results: No differences for all the classes of antibody were observed among the groups of subjects from the endemic village of Kaniza (P>0.05) or between these subjects and those from the non-endemic village of Klakar (P>0.05). The values of IgM anti-THP antibodies exceeded those of the IgA and IgG classes in all groups of subjects (P<0.05). The values for all three classes of antibodies were higher in the rural than the urban population (P<0. 05).
Conclusion: Determination of anti-THP antibodies was not found to be useful in the early diagnosis of endemic nephropathy. The results suggest that most of the anti-THP antibodies are 'natural' and/or cross reactive. The highest values observed in the rural population could probably be explained by exposure to some ubiquitous antigen or more likely they are consequences of fever.