Seroprevalence of Diphtheria Immunity Among Hiv-Infected Adults

Abstract

Introduction. At present, HIV-infected persons have a sufficient life expectancy that is close to the life expectancy of immunocompetent people due to antiretroviral therapy (ART). Availability of effective ART permitted to turn HIV infection from an acute and often fatal disease into a chronic latent infection, albeit rather complicated, but this gives doctors the opportunity to pay more attention to the needs of primary care for aging HIV-infected population [1,2,3].The immunosuppressed status due to HIV infection is a risk factor for morbidity and mortality caused by a number of infectious diseases, including those preventable by vaccination. Diphtheria is the clearest example of the constant threat to health around the world. In this disease there is no long-term protection [4,5,6].Studies of antitoxic immunity against diphtheria in HIV-infected adults in the world are very limited, and in Ukraine are conducted for the first time, which determines the relevance of the chosen topic.The aim of the study was to assess the intensity of immunity against diphtheria in HIV-infected adults.Materials and methods. The study was attended by 90 people living with HIV infection at the age of 22 to 60 years. The mean age was (M±m) 40.1±0.9 years (SD=8.8 years). Observations of HIV-infected patients were carried out on the basis of the "Dnipropetrovsk prof. Y.G. Popkova City Clinical Hospital No. 21. "DRC", City Center for Prevention and Control of HIV/AIDS in the city of Dnipro.Laboratory study of the levels of antidiphtheria antibodies in the observation group was carried out at the Diagnostic Center of SI "Dnipropetrovsk Medical Academy, MOH of Ukraine". Diagnostic test systems RIDASCREEN Diphtheria IgG (R-Biopharm AG, Germany) was used to estimate the immunity strength to diphtheria by means of immunoassay (ELISA). The examination was carried out in compliance with the manufacturer's instructions. The immunity status against diphtheria was estimated by determining the concentration of antibodies in IU/ml. The assessment of the anti-diphtheria immunity strengths was carried out according to the following criteria: up to 0.1 IU/mlprotection absent; 0.1-0.9 IU/mlminimum level of protection; 1.0-1.4 IU/mlmoderate level of protection; 1.5 IU/ml and above is a high level of protection. The control group involved 49 healthy immunocompetent volunteers from the corresponding age group (mean age 39.0±1.2 years) (p=0.44 by t-test).Statistical processing of the results was performed using STATISTICA v.6.1 licensed software (Statsoft Inc., USA, Serial No. AGAR909E415822FA). The critical level of statistical significance (p) was taken to be <0.05.Results of the research. This study identified significant differences between the titres of anti-toxic anti-diphtheria antibodies in HIV-infected and immunocompetent adults. It was established that the median of anti-diphtheria