Seronegative Infection with Toxoplasma gondii in Asymptomatic Human Immunodeficiency Virus Type 1 (HIV-1)-Infected Patients and in Blood Donors

Abstract

Background: Toxoplasmosis is a common opportunistic infection in AIDS patients. The routine diagnostics is based on serologic testing and IgG avidity index, but it may have limited utility in immunodeficient patients; thus, it is recommendable to detect T. gondii DNA in subjects with advanced HIV disease. The results of the studies published so far focused on patients with clinical symptoms of toxoplasmosis. Our study encompassed a group of HIV-infected subjects on cART therapy, without immunological disturbances and clinical symptoms of T. gondii infection. Methods: The study was retrospective, and samples were collected between 2013 and 2016. We evaluate the prevalence of serological (IgM, IgG, and avidity IgG) and molecular (DNA) T. gondii infection markers in asymptomatic HIV-infected patients and the control group using serologic (ELISA) and quantitative (real-time PCR) molecular testing. Results: Of 152 HIV-infected in routine follow-up tested for T. gondii IgM and IgG, 6 (3.9%) and 50 (32.9%) were positive, respectively. Of 168 serum samples from blood donors, 1 (0.6%) and 49 (29.2%) were IgM+ and IgG+ positive, respectively. IgM seroprevalence in HIV-infected patients was significantly higher than in blood donors. T. gondii DNA (genotype II) was identified in 47 (30.9%) HIV-infected patients, with 13 (8.6%) IgM−IgG− samples. In blood donors, T. gondii DNA was present in 15 (8.9%) IgM−IgG−. Conclusions: In both groups, T. gondii DNA was detectable in seronegative subjects, implying the need to supplement the routine serological testing via the molecular method. It can help the accurate monitoring of the reactivation of infection in asymptomatic HIV-infected persons, and the quick introduction of specific therapy, in blood donors, would be of high importance for safe blood donations.

The Medical Relevance of Toxoplasma Infections in Terms of the Safety of Blood Recipients under Immunosuppression—A Meta-Analysis

“…However, it is worth noting that anti- Toxoplasma antibodies persist long and do not necessarily mean an acute infection [ 22 ]. In turn, Pawełczyk et al [ 23 ], in a group of 168 blood donors, observed 1 (0.6%) IgM-positive and 49 (29.2%) IgG-positive subjects. Further research showed that 15 (8.9%) IgM-negative and IgG-negative blood donors had T. gondii DNA present.…”

Seroprevalence of Toxoplasma gondii among HIV Positive Patients under Surveillance in Greek Infectious Disease Units: A Screening Study with Comparative Evaluation of Serological Methods

“…Limited information exists on the incidence of T. gondii infection among HIV+ patients in Europe [14,15], and studies on its seroprevalence are scarce. HIV+ patients are at risk of developing opportunistic infections such as toxoplasmosis, Pneumocystis jirovecii pneumonia, and leishmaniasis due to their compromised immune system.…”

Advances and Challenges in Diagnostics of Toxoplasmosis in HIV-Infected Patients

“…Toxoplasmosis could be a lethal opportunistic infection after allogeneic hematopoietic cell transplantation [ 58 ]. Therefore, using both serologic and molecular methods in blood donors would be highly important for safe blood donations [ 81 ]. To prevent toxoplasmosis, serological screening of donors and recipients before transplantation is of primary importance to identify patients at high risk of toxoplasmosis, i.e., seropositive hematopoietic stem cell transplant recipients and mismatched (seropositive donor/seronegative recipients) solid organ transplant recipients.…”

“…Serological tests may fail to detect the disease in immunocompromised patients because the titers of anti- Toxoplasma antibodies may fail to rise [ 63 ]. Thus, it is recommendable to detect parasite DNA in patients with advanced HIV disease [ 81 ]. It should be emphasized that molecular diagnostics do not depend on the immunological condition of the host.…”