Concurrent allergy and helminthiasis in underprivileged urban South African adults previously residing in rural areas

Evaluating the Toxocara cati extract as a therapeutic agent for allergic airway inflammation

BACKGROUND

The hygiene hypothesis suggests that early life exposure to helminth infections can reduce hypersensitivity in the immune system.

OBJECTIVE

The present study aims to evaluate the effects of Toxocara cati (T. cati) somatic products on allergic airway inflammation.

METHODS

Between 2018 and 2020, T. cati adult worms were collected from stray cats in Mashhad, Iran (31 out of 186 cats), and their somatic extract was collected. Thirty BALB/c mice were equally divided into three groups, including the OVA group (sensitized and challenged with ovalbumin), the somatic administered group (received somatic extract along with ovalbumin sensitization), and the PBS group (sensitized and challenged with phosphate buffer saline). Bronchoalveolar lavage (BAL) fluid was collected to assess the number of cells, and lung homogenates were prepared for cytokine analysis. Histopathological analysis of the lungs was performed, and inflammatory cells and mucus were detected. Cytokine levels (IL-4, IL-5, IL-10) were measured using enzyme-linked immunosorbent assay (ELISA), and ovalbumin-specific immunoglobulin E (IgE) levels were determined using a capture ELISA.

RESULTS

The somatic group significantly decreased regarding the lung pathological changes, including peribronchiolitis, perivasculitis, and eosinophil influx, compared to the group treated with ovalbumin alone. These changes were accompanied by a decrease in proinflammatory cytokines IL-4 and IL-5 and an increase in the anti-inflammatory cytokine IL-10, indicating a shift toward a more balanced immune response. The number of inflammatory cells in the BAL fluid was also significantly reduced in the somatic group, indicating a decrease in inflammation.

CONCLUSION

These preclinical findings suggest that in experimental models, T. cati somatic extract exhibits promising potential as a therapeutic agent for mitigating allergic airway inflammation. Its observed effects on immune response modulation and reduction of inflammatory cell infiltration warrant further investigation in clinical studies to assess its efficacy and safety in human patients.

Anaemia and Nutritional Status during HIV and Helminth Coinfection among Adults in South Africa

Sub-Saharan Africa is burdened with helminthiasis and HIV/AIDS, and there is a significant overlap between these infections. However, little is known about the extent of anaemia and malnutrition in HIV/AIDS and helminth coinfected adults. The study investigated the anaemia profiles and nutritional status of HIV and helminth coinfected adult South Africans. Stool samples were collected from participants (N = 414) for parasite detection using the Kato−Katz and Mini Parasep® SF techniques. Blood was collected to determine participants’ HIV status, micro- and macronutrients, haematological parameters, and Ascaris lumbricoides-specific IgE and IgG4 levels. Thereafter, participants were stratified into single infection (HIV or helminths), coinfection, and uninfected controls (no HIV and helminth) groups. The majority (74.9%) of participants had CD4 counts of >500 cells/μL, indicating no significant immunosupression. The coinfected group had an overall anaemia prevalence of 16.9%, which was lower than that of the HIV-infected group (44.6%) and higher than helminth infected group (15.4%). Overall helminth prevalence was 33%, with Ascaris lumbricoides being the most prevalent. The coinfected group also had lower vitamin A (p = 0.0107), calcium (p = 0.0002), and albumin (p < 0.0001) levels compared to HIV/helminth uninfected controls. Unexpectedly, the coinfected group had the highest serum iron levels, followed by the helminth-infected and control groups, both of which had similar iron levels, and finally, the HIV-infected group, which had the lowest iron levels (p = 0.04). Coinfected adults may be prone to micronutrient deficiency and anaemia. Further research and intervention programmes are required in this neglected field.

Immunological Interactions between Intestinal Helminth Infections and Tuberculosis

Helminth infections are among the neglected tropical diseases affecting billions of people globally, predominantly in developing countries. Helminths’ effects are augmented by coincident tuberculosis disease, which infects a third of the world’s population. The role of helminth infections on the pathogenesis and pathology of active tuberculosis (T.B.) remains controversial. Parasite-induced suppression of the efficacy of Bacille Calmette-Guerin (BCG) has been widely reported in helminth-endemic areas worldwide. T.B. immune response is predominantly proinflammatory T-helper type 1 (Th1)-dependent. On the other hand, helminth infections induce an opposing anti-inflammatory Th2 and Th3 immune-regulatory response. This review summarizes the literature focusing on host immune response profiles during single-helminth, T.B. and dual infections. It also aims to necessitate investigations into the complexity of immunity in helminth/T.B. coinfected patients since the research data are limited and contradictory. Helminths overlap geographically with T.B., particularly in Sub-Saharan Africa. Each disease elicits a response which may skew the immune responses. However, these effects are helminth species-dependent, where some parasites have no impact on the immune responses to concurrent T.B. The implications for the complex immunological interactions that occur during coinfection are highlighted to inform government treatment policies and encourage the development of high-efficacy T.B. vaccines in areas where helminths are prevalent.