Interaction of Clostridioides difficile infection with frailty and cognition in the elderly: a narrative review

PURPOSE

Clostridioides difficile infection (CDI) is the leading cause of antibiotic-related diarrhea and healthcare-associated infections, affecting in particular elderly patients and their global health. This review updates the understanding of this infection, with focus on cognitive impairment and frailty as both risk factors and consequence of CDI, summarizing recent knowledge and potential mechanisms to this interplay.

METHODS

A literature search was conducted including terms that would incorporate cognitive and functional impairment, aging, quality of life, morbidity and mortality with CDI, microbiome and the gut-brain axis.

RESULTS

Advanced age remains a critical risk for severe disease, recurrence, and mortality in CDI. Observational and quality of life studies show evidence of functional loss in older people after acute CDI. In turn, frailty and cognitive impairment are independent predictors of death following CDI. CDI has long-term impact in the elderly, leading to increased risk of readmissions and mortality even months after the acute event. Immune senescence and the aging microbiota are key in susceptibility to CDI, with factors including inflammation and exposure to luminal microbial products playing a role in the gut-brain axis.

CONCLUSIONS

Frailty and poor health status are risk factors for CDI in the elderly. CDI affects quality of life, cognition and functionality, contributing to a decline in patient health over time and leading to early and late mortality. Narrative synthesis of the evidence suggests a framework for viewing the cycle of functional and cognitive decline in the elderly with CDI, impacting the gut-brain and gut-muscle axes.

Interleukin-12 enhancement of antigen-specific lymphocyte proliferation correlates with stage of human immunodeficiency virus infection

The effect of interleukin (IL)-12 on T lymphocyte function was assessed in 47 human immunodeficiency virus (HIV)-infected persons of different disease stages and 16 seronegative controls. Lymphoproliferative responses (LPR) were measured to various HIV and non-HIV antigens and mitogens using peripheral blood mononuclear cells cultured with or without IL-12. Without exogenous IL-12, 96% of HIV-seropositive persons responded to mitogens, 77% to >=1 non-HIV antigen, and 11% to >=1 HIV antigen. Supplementation with IL-12 augmented LPR of HIV-seropositive persons to non-HIV antigens; however, the effect was greatest for those with higher CD4 cells (40% vs. 9% for those with >200 vs. <=200 CD4 cells/mm3). Addition of IL-12 also enhanced LPR to HIV antigens in 30% of subjects. This effect was most pronounced for those with>500 CD4 cells/mm3 (56% [P<. 05]). These findings suggest that impaired T lymphocyte recognition of foreign antigen, including HIV, can be reconstituted in part for selected HIV-seropositive persons.

Zygomycosis (mucormycosis) and HIV infection: report of three cases and review

We report three cases of zygomycosis (mucormycosis) occurring in three individuals infected with the human immunodeficiency virus (HIV) and review 12 other published cases. We present the only two case reports of disseminated zygomycosis in AIDS patients, and the only AIDS patient with renal zygomycosis to survive without nephrectomy, receiving intravenous (i.v.) amphotericin alone. Coinfection with zygomycosis and HIV is rare, occurs primarily in patients with low CD4+ lymphocyte counts, does not always require the usual predisposing conditions for zygomycosis, and may be the presenting opportunistic infection among HIV-infected persons. Transient episodes of neutropenia occurring within 4 months before presentation may be a risk factor for this disease. Zygomycosis may arise in multiple sites including the basal ganglia, cutaneous tissue, kidney, respiratory tract, and may be disseminated. Occurring more commonly in, but not restricted to, injection drug users, it is significantly associated with sites other than basal ganglia in those patients with advanced HIV disease or AIDS. The presenting symptoms are related to the site of involvement, and the illness may develop insidiously or progress rapidly to a fulminant course. Successful therapy usually consists of surgical debridement and intravenous amphotericin B. Overall mortality in this review is 40%, and is significantly associated with sites of disease inaccessible to surgical debridement.