Treatment of toxoplasmic lymphadenitis with co-trimoxazole: double-blind, randomized clinical trial

Abstract

Background: Lymphadenitis is one of the presenting signs of toxoplasmosis. Co-trimoxazole (CTM) has a good therapeutic effect on ocular and cerebral infections caused by Toxoplasma gondii. Since this infection is endemic in Ahvaz and because of the lack of investigations into the therapeutic effects of CTM in toxoplasmic lymphadenitis (TL), this study was performed from 2005 to 2007 to determine the therapeutic effects of CTM on TL in Ahvaz.

Methods: Forty-six patients with TL were enrolled in this randomized, double-blind, placebo-controlled trial study. Diagnosis was based on clinical examination, serological tests (chemiluminescent), and histopathological examinations. Palpable lymph nodes, IgM >8IU, and follicular hyperplasia were defined as positive findings. Patients were randomly assigned to the comparison groups (23 patients in each group). The CTM patients were treated with 48 mg/kg/day CTM divided into two doses, for 1 month. The placebo patients were treated with placebo for 1 month. The primary endpoint for treatment response was 1 month. Follow-up with physical and serological examinations occurred at 6 months. The secondary endpoint was at 6 months. Clinical response was defined as no palpable lymph nodes and serological response as IgM <6IU; a patient was cured if the lymph nodes were no longer palpable and IgM was <6IU. Results were analyzed using SPSS software and the Chi-square test.

Results: At the end of treatment, a clinical response was observed in 15 (65.2%) in the CTM group and five (21.7%) in the placebo group. A serological response was seen in 65.2% of the CTM group and 13.0% of the placebo group. The cure rate was 65.2% in the CTM group and 13.1% in the placebo group. There was a significant difference in therapeutic effect between the two groups (52.2%, 95% confidence interval 32.1-72%, p<0.001). There was no difference in the site of infection between the two groups (p>0.05).

Conclusion: CTM has a good therapeutic effect in TL and may be used in selected patients for whom treatment is required.