[The value of the immunoglobulin G avidity test for the serologic diagnosis of brucellosis].
Authors: Kutlu SS,Celikbaş A,Ergönül O,Kutlu M,Aksaray S,Güvener E,Dokuzoğuz B,
Address: Ankara Numune Eğitim ve Araştirma Hastanesi, Birinci Infeksiyon Hastaliklari ve Klinik Mikrobiyoloji Kliniği, Ankara.
Journal: Mikrobiyol Bul.
Publication: 2003 Oct;37(4):261-7.
In order to investigate the value of immunoglobulin G (IgG) avidity test for the serological diagnosis of Brucella infections, a total of 118 patients (74 male, 44 female; mean age: 43 +/- 18.7 years) were included into the present study. The patients have been diagnosed with the characteristic clinical findings, > or = 1/160 antibody titers in standard tube agglutination (STA) test and/or blood culture positivities. Brucella spp. have been grown in blood cultures of 78 patients, and STA test results were found positive (> or = 1/160 titers) in 117 patients. The diagnosis of a patient with 1/80 STA titer was based on the blood culture positivity. By enzyme immunoassay (ELISA), 3 patients (2.5%) were found positive for IgM, 14 (11.9%) were positive for IgG, and 101 (85.6%) were positive for both IgM and IgG. The patients who were found IgG positive have been grouped according to their duration of complaints. Group 1 included 99 patients with the history of brucellosis < or = 6 months, and group 2 included 16 patients with the history of brucellosis > 6 months. IgG avidity test was performed by ELISA in 115 IgG positive serum samples, with the denaturation substance (8 M urea). The cut-off value for IgG avidity index (AI) was accepted as 40%, and the avidity maturation period was defined as 6 months. As a result, the rates of patients who had low IgG AI in group 1 and 2 were found as 91.9% and 43.7%, respectively, while these rates were 8.1% and 56.3% for the presence of high IgG AI, respectively. The rate of low AI in group 1 was an expected result, while the rate was more than expected in group 2, indicating that Brucella antibodies with low avidity indices would not be helpful for the diagnosis of a recent infection, while Brucella antibodies with high avidity indices would be useful for the elimination of a recent infection.
The contents within traveldoctoronline are presented only for informational purposes and cannot substitute for professional health care or any other medical treatment.All users of this website with health problems should be oblige always to consult their medical doctor before starting any treatment.