The relation between salivary IgA and caries in renal transplant patients

Objective. The purpose of this study was to evaluate the effect of immunosu ppressive drugs on the level of salivary immunoglobulin A (IgA) in patients who have received kidney transplants and the relation between the levels o f salivary IgA and dental caries incidence. Study design. Patients who had undergone renal transplantation (n = 28. age d 18-54) were divided into 3 groups according to postsurgical period (0-6 m onths [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 cli nically, and proximal caries were examined clinically and radiographically; caries status was determined according to the decay surface index. The fin dings were evaluated statistically by means of correlation analysis, the Ko lmogorov-Smirnov test, and the 1-way Kruskal Wallis analysis of variance me thod. Results. Salivary IgA levels of the patients who had undergone renal transp lantation were found to be significantly lower than those of the control pa tients (G(1) = 6.76 mg/dL, G(2) = 6.80 mg/dL, G(3) = 7.84 mg/dL, and contro l group = 10.84 mg/dL, P < .001). However, the caries status of the patient s who had undergone renal transplantation was not different from that of th e control subjects for the first year after the transplant operation. The s alivary IgA values of the 3 groups of patients who had undergone transplant ation were not significantly different from each other. Thus, it was observ ed that a decrease in the level of salivary IgA does not result in an incre ase in caries incidence within 12 months after renal transplantation. The c aries rate in the third group of patients who had undergone renal transplan tation was found to be significantly different from those in the first and second groups. Conclusion. Low salivary IgA levels caused by immunosuppression are not cor related or associated with higher levels of dental caries within the first 12 months after renal transplantation. However, the incidence of dental car ies was higher for patients who had undergone renal transplantation than fo r control subjects 12 months after renal transplantation. Because of the di agnostic processes used, dental caries may not become evident until after 1 2 months.