Association between blood group antigens ABO, Rh, Kell, Kidd, Duffy and MNS and clinical forms of Chagas disease.

Background: The mechanisms that determine the progression to cardiac or digestive forms of chronic Chagas disease (CD) are still unclear. We assessed the association between blood group antigens ABO, Rh, Kell, Kidd, Duffy and MNS, and chronic CD clinical forms.

Methods: Patients were included consecutively between March 2013 and April 2016. Clinical and epidemiological data were obtained from electronic medical records and interviews. Classification of CD clinical forms followed the Brazilian Consensus on CD. The ID-Gel Card technology from Bio-Rad (Diamed/Bio-Rad Latin America, MG, Brazil) was used to analyze the blood group antigens.

Results: A total of 619 adult patients (56.9% women, mean age 60±12 y) were included. Patients' clinical forms of CD were classified as follows: indeterminate 29.1%, cardiac 55.4%, digestive 5.5% and mixed 10.0%. Logistic regression analysis adjusted for age, comorbidities and time away from an endemic area revealed that the S+s- allele of the MNS blood type was associated with a lower odds of cardiac disease and that the B blood group type was associated with a higher odds of digestive disease. All other blood types did not have an association with CD clinical form.

Conclusions: Blood group systems ABO and MNS were associated with chronic CD clinical forms.