Isotype Profile of Specific Antibodies after Chronic Exposure to Microcystins

Background: The detection of microcystins in blood, respiratory mucosa, and urine samples to diagnose acute or chronic microcystin intoxication is difficult and requires sophis-ticated analysis techniques. Finding simple and quick methods to assess the exposure of indi-viduals to microcystins is crucial. Objective: This study aims to assess the presence of specific antibodies (IgG, IgE, IgA, and IgM) against microcystin-LR in individuals exposed to cyanobacterial blooms as a non-com-plex biomarker. Methods: Blood samples were taken to reveal the presence of specific antibodies as well as to measure a standard set of biochemical parameters. All volunteers were administered a ques-tionnaire regarding their water usage, health status, and habits. Significant differences in the antibody content were studied between exposed and non-exposed people to cyanobacterial blooms. Results: We found that out of 73 studied individuals, 87.7% of them showed positive results for at least one of the four types of antibodies tested. The prevalent isotype was IgE, and sig-nificant differences were detected for all isotypes between the exposed and non-exposed groups. The biochemical profile was altered in some cases. Conclusion: The presence of specific antibodies in serum could be used as exposure biomarkers to complement epidemiological studies and medical diagnosis of microcystin intoxications. The in-house ELISA method, developed by our group for the detection of antibodies, should now be improved in terms of specificity and accuracy. These findings also indicate that more re-search should be conducted on the protective role and duration of antibodies.