Abstract

Background: The detection of microcystins in blood, respiratory mucosa, and urine samples to diagnose acute or chronic microcystin intoxication is difficult and requires sophisticated analysis techniques. Finding simple and quick methods to assess the exposure of individuals 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-complex 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 questionnaire 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 significant 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 research should be conducted on the protective role and duration of antibodies.

Keywords: Microcystins, chronic exposure, specific antibodies, population settlement, San Roque reservoir, exposure biomarkers, cyanobacterial blooms.