Relationship Between Anemia and Systemic Inflammation in People Living With HIV and Tuberculosis: A Sub-Analysis of the CADIRIS Clinical Trial

Prevalence and factors associated with moderate-to-severe anaemia among virally suppressed people with HIV at a tertiary hospital in Zambia

OBJECTIVE

Anaemia is associated with an increased risk of disease progression and all-cause mortality among HIV-infected individuals, regardless of the type of anaemia, but the magnitude of the risk is greater with more severe forms of anaemia. Although anaemia PLWH has been extensively studied, the focus has primarily been on its prevalence and association with disease progression in untreated or poorly controlled HIV cases. This study aimed to investigate the prevalence, and factors associated with moderate-to-severe anaemia among virally suppressed HIV patients at a tertiary hospital in Zambia.

METHODS

We conducted a cross-sectional study of ART-treated PLWH for at least 6 months at Livingstone University Teaching Hospital (LUTH). Sociodemographic, clinical, and laboratory were the data collected. The primary outcome moderate to severe anaemia was defined as follows; moderate anemia as haemaoglobin levels between 8.0-10.9 g/ and severe anemia as haemoglobin levels less than 8.0 g/dL according to the WHO classification. Logistic regression was performed to identify factors associated with moderate-to-severe anaemia.

RESULTS

Among 823 participants with viral suppression, the overall prevalence of anaemia and moderate-to-severe anaemia was 29.4% (n = 242; 95% confidence interval (CI): 26.3-32.6) and 14.2% (n = 117, 95% CI: 11.7-18), respectively. In the adjusted logistic regression analysis, women had higher odds of moderate to severe anaemia compared to men (AOR 2.618, 95% CI 1.182-5.799). Lymphocyte count (AOR 0.525, 95% CI 0.31-0.90) and higher BMI (AOR 1.0671, 95% CI 1.01-1.13) were also significant factors. Microcytosis (AOR 49.79, 95% CI 12.95-191.49) and normocytosis (AOR 4.38, 95% CI 1.22-15.75) were strongly associated with higher odds compared to macrocytosis. NNRTI treatment was associated with higher odds of anaemia compared to INSTI treatment (AOR 5.231, 95% CI 1.04-26.33). Traditional risk factors for anaemia like CD4+ count and tuberculosis infection were not significant.

CONCLUSION

We found a higher prevalence of anaemia and moderate-to-severe anaemia in virally suppressed PLWH, suggesting factors beyond HIV contribute to the persistence of anaemia in this cohort. Women, lower lymphocyte count, higher BMI, low mean corpuscular volume (microcytosis) indicative of microcytic anaemia, and NNRTI-based ART regimens were independently associated with moderate-to-severe anaemia. Further research is warranted to explain the underlying mechanisms and optimize clinical management to improve outcomes among virally suppressed PLWH.

Mechanisms and Cardiorenal Complications of Chronic Anemia in People with HIV

Chronic anemia is more prevalent in people living with HIV (PLWH) compared to the general population. The mechanisms that drive chronic anemia in HIV are multifaceted and include functional impairment of hematopoietic stem cells, dysregulation of erythropoietin production, and persistent immune activation. Chronic inflammation from HIV infection adversely affects erythropoiesis, erythrocyte lifespan, and erythropoietin response, leading to a heightened risk of co-infections such as tuberculosis, persistent severe anemia, and increased mortality. Additionally, chronic anemia exacerbates the progression of HIV-associated nephrotoxicity and contributes to cardiovascular risk through immune activation and inflammation. This review highlights the cardinal role of chronic inflammation as a link connecting persistent anemia and cardiovascular complications in PLWH, emphasizing the need for a universal understanding of these interconnected pathways for targeted interventions.

Effect of the relationship between anaemia and systemic inflammation on the risk of incident tuberculosis and death in people with advanced HIV: a sub-analysis of the REMEMBER trial

Background

Tuberculosis (TB) is an infectious morbidity that commonly occurs in people living with HIV (PWH) and increases the progression of HIV disease, as well as the risk of death. Simple markers of progression are much needed to identify those at highest risk for poor outcome. This study aimed to assess how baseline severity of anaemia and associated inflammatory profiles impact death and the incidence of TB in a cohort of PWH who received TB preventive therapy (TPT).

Methods

This study is a secondary posthoc analysis of the AIDS Clinical Trials Group A5274 REMEMBER clinical trial (NCT0138008), an open-label randomised clinical trial of antiretroviral-naïve PWH with CD4 <50 cells/μL, performed from October 31, 2011 to June 9, 2014, from 18 outpatient research clinics in 10 low- and middle-income countries (Malawi, South Africa, Haiti, Kenya, Zambia, India, Brazil, Zimbabwe, Peru, and Uganda) who initiated antiretroviral therapy and either isoniazid TPT or 4-drug empiric TB therapy. Plasma concentrations of several soluble inflammatory biomarkers were measured prior to the commencement of antiretroviral and anti-TB therapies, and participants were followed up for at least 48 weeks. Incident TB or death during this period were primary outcomes. We performed multidimensional analyses, logistic regression analyses, survival curves, and Bayesian network analyses to delineate associations between anaemia, laboratory parameters, and clinical outcomes.

Findings

Of all 269 participants, 76.2% (n = 205) were anaemic, and 31.2% (n = 84) had severe anaemia. PWH with moderate/severe anaemia exhibited a pronounced systemic pro-inflammatory profile compared to those with mild or without anaemia, hallmarked by a substantial increase in IL-6 plasma concentrations. Moderate/severe anaemia was also associated with incident TB incidence (aOR: 3.59, 95% CI: 1.32-9.76, p = 0.012) and death (aOR: 3.63, 95% CI: 1.07-12.33, p = 0.039).

Interpretation

Our findings suggest that PWH with moderate/severe anaemia display a distinct pro-inflammatory profile. The presence of moderate/severe anaemia pre-ART was independently associated with the development of TB and death. PWH with anaemia should be monitored closely to minimise the occurrence of unfavourable outcomes.

Funding

National Institutes of Health.