Higher levels of TNF and IL-4 cytokines and low miR-182 expression in visceral leishmaniasis-HIV co-infected patients

Insights to the HIV-associated visceral leishmaniasis clinical outcome: lessons learned about immune mediated disorders

Most cases of visceral leishmaniasis (VL) and human immunodeficiency virus (HIV) co-infection (VL/HIV) in the Americas occur in Brazil, and the prevalence of VL/HIV has been increasing since 2019, reaching 19% in 2023. This association presents a challenge for the management of VL, since both VL and HIV infection share immunopathogenic characteristics that can reciprocally affect co-infected patients. Thus, VL may contribute to the immunosuppression and other immunological disturbances associated with the rapid progression to acquired immunodeficiency syndrome (AIDS), whereas HIV infection accelerates the development of active VL and reduces the probability of a successful response to anti-Leishmania therapy, resulting in an increase in the relapse and lethality rates of VL. In this synergistic impairment, one of the most critical hallmarks of VL/HIV co-infection is the enhancement of immunosuppression and intense chronic immune activation, caused not only by each infection per se, but also by the cytokine storm and translocation of microbial products. Thus, co-infected patients present with an impaired effector immune response that may result in inefficient parasitic control. In addition, the chronic activation environment in VL/HIV patients may favor progression to early immunosenescence and exhaustion, worsening the patients' clinical condition and increasing the frequency of disease relapse. Herein, we review the immunological parameters associated with the immunopathogenesis of VL/HIV co-infection that could serve as good biomarkers of clinical prognosis in terms of relapse and severity of VL.

Evaluation of Chemokines MIG and IP-10 as Immunological Biomarkers of Human Visceral Leishmaniasis: A Systematic Review

Visceral leishmaniasis (VL) is a neglected tropical disease that is potentially fatal when untreated. Current diagnostic methods have limitations that contribute to ongoing transmission and poor prognosis. Thus, new tests are needed to provide quick, accurate diagnoses and evaluate clinical progression and treatment efficacy. The monokine induced by interferon-gamma (MIG) and interferon-gamma-inducible protein 10 (IP-10) has been associated with the host susceptibility to VL with potential diagnostic and prognostic purposes. We performed a systematic review using four search databases (Scopus, PubMed, Web of Science, and MEDLINE) to identify studies assessing MIG and IP-10 as potential biomarkers in patients with VL across various clinical conditions. A total of 13 studies were potentially eligible and included in this review. The articles, in general, reveal that the chemokines MIG and IP-10 are elevated in response to infection by Leishmania spp., acting on the host's resistance to the development of the disease. They are associated with asymptomatic conditions and after VL treatment, and this relationship can be observed in both immunocompetent and immunocompromised individuals. Consequently, these chemokines hold relevance in the diagnoses and appropriate management of individuals with VL.

Evaluation of Proinflammatory Chemokines in HIV Patients with Asymptomatic Leishmania Infantum Infection

Asymptomatic Leishmania infantum, when associated with HIV, can become severe and potentially fatal. In this co-infection, the worst prognosis may be influenced by the host's immunological aspects, which are crucial in determining susceptibility. Chemokines play an important role in this process by influencing the cellular composition at affected sites and impacting the disease's outcome. Therefore, the aim of this study was to evaluate proinflammatory chemokines in HIV patients with the asymptomatic L. infantum infection. In this cross-sectional study, the levels of CCL2, CCL5, CXCL8, MIG, and IP-10 were measured in 160 serum samples from co-infected patients (n = 53), patients with HIV (n = 90), and negative controls (n = 17). Quantification was determined by flow cytometry. The obtained data were statistically analyzed using the Kruskal-Wallis test, followed by the Dunn's post-test and the Spearman's correlation coefficient. Significance was set at p < 0.05. The chemokines CCL2, CCL5, MIG, and IP-10 exhibited higher levels in the HIV group compared to co-infection. However, the elevated levels of all these chemokines and their increased connectivity in co-infected patients appear to be important in identifying proinflammatory immune responses associated with the asymptomatic condition. Furthermore, a weak negative correlation was observed between higher levels of CXCL8 and lower viral loads in co-infected patients.

Visceral leishmaniasis and HIV coinfection in Brazil: epidemiological profile and spatial patterns

BACKGROUND

Geographical overlap of human visceral leishmaniasis (HVL) and HIV infection favors occurrences of HVL/HIV coinfection. The increasing numbers of cases of HVL/HIV coinfection are a worldwide concern and knowledge of the factors involved can help in developing preventive measures.

METHODS

We aimed to identify spatial patterns and describe the epidemiological profile of HVL/HIV coinfection in Brazil from 2007 to 2015. This was an ecological study, in which thematic maps were created through geoprocessing tools, based on secondary data obtained from open-access platforms, to identify priority areas for interventions for controlling HLV/HIV coinfection, using the TerraView 4.2.2 software.

RESULTS

We found spatial autocorrelations between the HVL/HIV rates of neighboring municipalities according to the global Moran index (0.10; p<0.01). The highest HVL/HIV rate was in the central-western region. Among the epidemiological characteristics according to the regions, an increasing trend in the annual variation rate was observed, with positive values over the years and statistical significance (p<0.05) in the North with 1.62 (95% CI 0.57 to 2.69; p=0.02) and Northeast with 6.41 (95% CI 2.60 to 10.37; p=0.006). Similarly, increasing trends were observed in the states of Maranhão with 21.34 (95% CI 13.99 to 9.16; p<0.001) and Sergipe with 5.44 (95% CI 0.61 to 10.50; p=0.04).

CONCLUSIONS

Our results showed spatial overlap between occurrences of HVL and HIV with spatial patterns of HVL/HIV coinfection, thus revealing that the numbers of cases reported are increasing. Identifying areas with higher coinfection indices contributes to applying interventions and control measures among targeted populations, to prevent new cases.

The cytokine/chemokine response in Leishmania/HIV infection and co-infection

HIV infection progressively weakens the immune system by infecting and destroying cells involved in host defense. Viral infection symptoms are generated and aggravated as immunosuppression progresses, triggered by the presence of opportunistic infections: among these is leishmaniasis, a disease caused by the intracellular parasite Leishmania. The incidence of this co-infection is growing progressively due to the geographic distribution overlap. Both pathogens infect monocytes/macrophages and dendritic cells, although they can also modulate the activity of other cells without co-infecting, such as T and B lymphocytes. Leishmania/HIV co-infection could be described as a system comprising modulations of cell surface molecule expression, production of soluble factors, and intracellular death activities, leading ultimately to the potentiation of infectivity, replication, and spread of both pathogens. This review describes the cytokine/chemokine response in Leishmania/HIV infection and co-infection, discussing how these molecules modulate the course of the disease and analyzing the therapeutic potential of targeting this network.

Non-coding RNA-based regulation of inflammation

Inflammation is a multifactorial process and various biological mechanisms and pathways participate in its development. The presence of inflammation is involved in pathogenesis of different diseases such as diabetes mellitus, cardiovascular diseases and even, cancer. Non-coding RNAs (ncRNAs) comprise large part of transcribed genome and their critical function in physiological and pathological conditions has been confirmed. The present review focuses on miRNAs, lncRNAs and circRNAs as ncRNAs and their potential functions in inflammation regulation and resolution. Pro-inflammatory and anti-inflammatory factors are regulated by miRNAs via binding to 3'-UTR or indirectly via affecting other pathways such as SIRT1 and NF-κB. LncRNAs display a similar function and they can also affect miRNAs via sponging in regulating levels of cytokines. CircRNAs mainly affect miRNAs and reduce their expression in regulating cytokine levels. Notably, exosomal ncRNAs have shown capacity in inflammation resolution. In addition to pre-clinical studies, clinical trials have examined role of ncRNAs in inflammation-mediated disease pathogenesis and cytokine regulation. The therapeutic targeting of ncRNAs using drugs and nucleic acids have been analyzed to reduce inflammation in disease therapy. Therefore, ncRNAs can serve as diagnostic, prognostic and therapeutic targets in inflammation-related diseases in pre-clinical and clinical backgrounds.

The Comparison of the IFN-ɤ, TNF-α and IL-10 Cytokines in Healing and Non-healing Cutaneous Leishmaniasis

Background:

Leishmaniasis is one of the main vectors borne and neglected tropical parasitic diseases. T cell cytokine responses are highly important in the presentations of disease such as control or progression, and understanding of the host immunological response is valuable in diagnosis, follow-up, and vaccine designs. In the current study, the profile of IFN-ɤ, TNF-α, and IL-10 cytokines was investigated through the ELISA technique in PBMCs isolated from antimony resistance and susceptible patients.

Methods:

In this experimental study, 54 patients with healing (n=27) or non-healing (n=27) CL were recruited. Lesion samples were collected to determine the genotype of Leishmania spp. and peripheral blood mononuclear cells (PBMCs) were obtained to evaluate the cytokines profiles using soluble Leishmania antigen (SLA) and phytohaemagglutinin (PHA) mitogen. Cytokines were assessed by the ELISA technique

Results:

The IFN-ɤ and TNF-α cytokines were significantly increased in the healing group treated with both SLA antigen and PHA mitogen (P<0.001). The level of IL-10 was significantly increased in non-healing and significantly declined in healing groups (P<0.001).

Conclusion:

The profile of IFN-ɤ, TNF-α, and IL-10 cytokines are crucially associated with the response of treatment.