The relation between salivary IgA and caries in renal transplant patients

Objective. The purpose of this study was to evaluate the effect of immunosuppressive drugs on the level of salivary immunoglobulin A (IgA) in patients who have received kidney transplants and the relation between the levels of salivary IgA and dental caries incidence. Study design. Patients who had undergone renal transplantation (n = 28. aged 18-54) were divided into 3 groups according to postsurgical period (0-6 months [G(1)], 6-12 months [G(2)], and >12 months [G(3)]). A healthy control group (n = 10, aged 17-49) was also included in this study. Saliva samples were collected from all patients by the spitting method. After collection, the samples were frozen immediately at -40 degrees C until analysis by the single radial immunodiffusion method, All fissure caries were examined clinically, and proximal caries were examined clinically and radiographically; caries status was determined according to the decay surface index. The findings were evaluated statistically by means of correlation analysis, the Kolmogorov-Smirnov test, and the 1-way Kruskal Wallis analysis of variance method. Results. Salivary IgA levels of the patients who had undergone renal transplantation were found to be significantly lower than those of the control patients (G(1) = 6.76 mg/dL, G(2) = 6.80 mg/dL, G(3) = 7.84 mg/dL, and control group = 10.84 mg/dL, P < .001). However, the caries status of the patients who had undergone renal transplantation was not different from that of the control subjects for the first year after the transplant operation. The salivary IgA values of the 3 groups of patients who had undergone transplantation were not significantly different from each other. Thus, it was observed that a decrease in the level of salivary IgA does not result in an increase in caries incidence within 12 months after renal transplantation. The caries rate in the third group of patients who had undergone renal transplantation was found to be significantly different from those in the first and second groups. Conclusion. Low salivary IgA levels caused by immunosuppression are not correlated or associated with higher levels of dental caries within the first 12 months after renal transplantation. However, the incidence of dental caries was higher for patients who had undergone renal transplantation than for control subjects 12 months after renal transplantation. Because of the diagnostic processes used, dental caries may not become evident until after 12 months.