Clinical and laboratory predictors of antitoxic immunity against diphtheria and tetanus in adults with HIV infection

Antiretroviral therapy has made HIV infection a chronic controlled disease, where aspects of the immunoprophylaxis of infectious diseases have acquired important clinical significance. The goal of the study was to determine the clinical and laboratory predictors of antitoxic immunity against diphtheria and tetanus in HIV-infected adults. The study included 90 HIV-infected patients aged 22 to 60 years (main group). The control group consisted of 49 immunocompetent volunteers of the corresponding age. The levels of anti-diphtheria and anti-tetanus antibodies were determined by ELISA using the diagnostic test systems RIDASCREEN Diphtheria IgG and RIDASCREEN Tetanus IgG (R-Biopharm AG, Germany). Statistical processing was performed using the licensed software product STATISTICA v.6.1. Significant differences were found between the titers of antitoxic antibodies in HIV-infected and immunocompetent adults. According to the correlation analysis, the decrease in the titers of antidiphtheria antibodies was revealed with an increase in the age of the HIV-infected patient (rs=-0.21; p=0.05). The fact of smoking (rs=-0.31; p=0.003), lowered body weight (BMI<18.5 kg/m2) (rs=-0.29; p=0.006), the presence of arterial hypertension (rs=-0.38; p<0.001), a history of bone fractures over the past 5 years (rs=-0.38; p<0.001), anemia (rs=-0.21; p=0.049), thrombocytopenia (rs=-0.44; p<0.001), accelerated ESR (rs=-0.61; p<0.001), the presence of hairy leukoplakia of the tongue (rs=-0.23; p=0.027), frequent infections caused by herpes simplex (rs=-0.52; p=0.003) and varicella zoster virus (rs=-0.34; p=0.013) are associated with low levels of antidiphtheria antibodies. A direct relationship was found between the intensity of anti-diphtheria immunity and patients receiving OST (rs=+0.54; p=0.003) and with a history of injuries with impaired skin integrity (rs=+0.31; p=0.003). Decreased anti-tetanus immunity in HIV-infected patients was also associated with smoking (rs=-0.48; p<0.001), decreased BMI (rs=-0.71; p<0.001), anemia (rs=-0.33; p=0.002), thrombocytopenia (rs=-0.75; p<0.001), a history of bone fractures over the past 5 years (rs=-0.67; p<0.001); the total number of HIV-associated opportunistic diseases (rs=-0.42; p<0.001), including the presence of oropharyngeal candidiasis (rs=-0.23; p=0.032) and hairy leukoplakia of the tongue (rs=-0.57; p<0.001), history of Herpes Zoster in the past (rs=-0.48; p<0.001), with frequent relapses of diseases caused by herpes simplex viruses (rs=-0.78; p<0.001) and repeated episodes of herpes zoster (rs=-0.74; p<0.001), as well as with pathology of the skin (rs=-0.55; p<0.001). Protective predictors of anti-tetanus antitoxic immunity strength were established: male gender (rs=+0.22; p=0.039), parenterally acquired HIV infection (rs=+0.21; p=0.05), HIV-infected patients receiving OST (rs=+0.40; p=0.041). A direct relationship was found with the decreased level of hemoglobin (rs=+0.41; p<0.001), the increase of relative number of lymphocytes in the blood (rs=+0.21; p=0.05), as well as with living in rural areas (rs=+0.40; p<0.001) and the presence of injuries with impairment of skin integrity (rs=+0.84; p<0.001). Clinical and laboratory predictors of strength of antitoxic immunity against diphtheria and tetanus in HIV-infected adults were identified, which allows us to create an individual “vaccination roadmap” for patients in this category.