Sequence variations in subjects with self-reported multiple chemical sensitivity (sMCS): a case-control study

Polymorphisms in several genes contribute to interindividual differences in the metabolism of xenobiotics, and may lead to toxicity and disease. The balance between activation and/or detoxification processes may influence an individual's susceptibility to disease. One postulated mechanism underlying multiple chemical sensitivity (MCS) is based on increased metabolism of xenobiotics. The aim of the present study was to determine such polymorphisms in cases with self-reported MCS (sMCS) and controls. sMCS cases (14 men, 45 women, mean age: 48 yr) and controls (14 men, 26 women, mean age: 44 yr) of the same anthroposphere were characterized using the MCS-questionnaire from Huppe and coworkers (2000) and a standardized questionnaire for living conditions and living factors. Allelic frequencies of genomic variations for 5HTT, NAT1, NAT2, PON1, PON2, and SOD2 were determined. The MCS questionnaire from Huppe et al. (2000) differentiated between cases and controls with 87.5% sensitivity and 90% specificity. Compared to controls the sMCS cases had lower exposures, especially to odorous factors, and worse social conditions. No significant differences of the allelic distribution of genetic polymorphisms in the genes for 5HTT, NAT1, NAT2, PON1, PON2, and SOD2 were found between cases and controls. The results are in contrast to the study of McKeown-Eyssen and coworkers (2004) but in accordance with the German MCS multicenter study. Although the MCS questionnaire from Huppe et al. (2000) allowed us to differentiate sMCS cases and controls, it was not strong enough for a discrimination based on sequence variations in genes for enzymes involved in xenobiotic metabolism. Therefore, further research needs to focus on a unique phenomenological characterization of MCS.

[Granulomatous skin disease after an exotic injury]

Piranhas are feared freshwater fishes commonly found in the waters of southern Venezuela to the north of Argentina. At present this species is a favourite domesticated article of our aquarists. The authors describe the histopathologic picture of a cutaneous lesion of the right hand thumb of a 60-year old piranha keeper who was bitten by this predatory fish. A firm node with increasing soreness gradually developed in the area of the lesion, and after 7 months the symptoms of the carpal tunnel syndrome were also present. Granulomatous foci--some sarcoid-like, others with central necrosis--were permeated with fibrinoid substance. Epithelioid granuloma cells with huge incorporated multinuclear elements were covered mainly by T-lymphocytes. Ziehl-Neelsen stain did not prove the presence of diagnostic acid-fast rods. Only in some macrophages rare acid-fast spheric microstructures were present in the cytoplasm. Both the local dermatologic finding and histological examination gave evidence that the skin was infected with atypical mycobacteria--swimming pool granuloma.