Effect of Toxoplasma co-inefected with intestinal helminthes on cell mediated immunity to tuberculosis patients

The effect of intestinal helminthes (IH) and Toxoplasma gondii (Tox) co-infection on anti-mycobacterium tuberculosis (MTB) immunity in patients with active pulmonary tuberculosis was studied in 96 patients of 4 groups. Thirteen patients had TB+IH+Tox (G1), 15 had TB+IH (G2), 21 had TB+Tox (G3) and 47 had TB (G4). The mean diameter of tuberculin and toxoplasmin tests was measured to assess cell mediated immunity. Anti-Toxoplasma IgG1 & IgG4 antibodies were sought in toxoplasmic patients by ELISA for Thelper1 (Th1) and Th2 cytokine responses respectively. All patients were treated by 6 months anti-MTB therapy. Specific anti-IH therapies were given for patients with concomitant IH. Sputum examination for acid fast bacilli was done 2 weeks post-treatment and duration of sputum clearance was recorded. The results showed that IH co-infection had significant negative effect on mean diameter of tuberculin test compared to G4 (5.87 +/- 0.08 vs 8.65 +/- 0.05 mm; P < 0.01). Concurrent Tox with TB significantly increased tuberculin test mean diameter (10.89 +/- 0.11 vs 8.65 +/- 0.05 mm; P < 0.05). Mean level of anti-Tox IgG1 among G3 was significantly higher than in G1 (0.88 +/- 0.05 vs 0.55 +/- 0.02; P < 0.001), but vice versa was with IgG4. Mean tuberculin diameter increased significantly post-treatment in all Gs except G3. Anti-Tox IgGC1 showed significant increase (0.55 +/- 0.02 to 0.82 +/- 0.03; P < 0.001) but IgG4 showed significant decrease (0.62 +/- 0.07 to 0.45 +/- 0.06, P < 0.01) post-treatment in G1, but G3 was insignificantly affected. The duration of sputum clearance was significantly longer in patients with IH co-infection compared to G4 (29 +/- 1 vs 21.8 +/- 4.6 days; P < 0.001).