Anti-Toxoplasma gondii antibodies in patients with beta-hemoglobinopathies: the first report in the Americas

Abstract\ud \ud Background\ud In Brazil, there have been no previous studies of Toxoplasma gondii infection in sickle cell anemia patients and carriers of severe forms of beta-thalassemia. This study evaluated T. gondii infection in patients with beta-hemoglobinopathies.\ud \ud \ud Methods\ud A total of 158 samples, 77 (48.7%) men and 81 (51.3%) women, were evaluated. Three groups were formed: G1 (85 patients with sickle cell disease); G2 (11 patients with homozygous beta-thalassemia; G3 (62 patients with heterozygous beta-thalassemia). ELISA was employed to identify anti-T. gondii IgM and IgG antibodies, and molecular analysis was performed to determine beta-hemoglobin mutations. Fisher’s exact test was used to compare frequencies of anti-T. gondii IgM and IgG antibodies in respect to gender and age.\ud \ud \ud Results\ud Anti-T. gondii IgG antibodies were found in 43.5% of individuals in G1, 18.1% in G2 and 50% in G3. All samples from G1 and G2 were seronegative for anti-T. gondii IgM antibodies, but 3.2% from G3 were seropositive. Considering anti-T. gondii IgG antibodies, no statistical significant differences were found between these groups nor in seroprevalence between genders within each group. Despite this, comparisons of the mean ages between G1, G2 and G3 were statistically significant (G2 vs. G1: p value = 0.0001; G3 vs. G1: p-value <0.0001; G3 vs. G2: p-value = 0.0001).\ud \ud \ud Conclusion\ud A comparison by age of patients with sickle cell anemia showed a trend of lower risk of infection among younger individuals. Therefore, this study demonstrates that T. gondii infection occurs in patients with beta-thalassemia and sickle cell anemia in Brazil as seen by the presence of anti-T. gondii IgM and IgG antibodies.This study was supported by grants from the FAPERP (Fundação de Apoio\ud à Pesquisa e Extensão de São José do Rio Preto) to CCBM and to MNF\ud and by FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo,\ud Brazil) 2011/15570-1 to GCSC; 2012/07716-9 to LCM; 2014/01706-7 to MNF;\ud 2015/04677-0 to CCBM). The opinions, assumptions, and conclusions or\ud recommendations expressed in this material are responsibility of the authors\ud and do not necessarily refect the views of FAPESP. The funders had no role in\ud study design, data collection and analysis, decision to publish, or preparation\ud of the manuscript