Helminth species-specific effects on IFN-γ producing T cells during active and latent tuberculosis.

BACKGROUND: Interferon-γ (IFN-γ) is a key cytokine inducing protective immune responses during tuberculosis (TB) infection. Helminth-induced immune responses may affect IFN-γ production by T cells, although its connection with disease severity and immune recovery during treatment is unexplored. We investigated the species-specific effect of helminths on the IFN-γ production by T cells in relation to disease severity during active and latent TB infection (LTBI). METHODS: In this study, 69 active pulmonary TB patients (PTB), 28 with LTBI and 66 healthy controls were included. Active TB was diagnosed using GenXpert MTB/RIF while QuantiFERON test (QFT) was used for the screening of healthy community controls (CCs) and for the diagnosis of LTBI. Helminth infection was identified by routine diagnosis whereas clinical disease severity was evaluated by the TB score. Intracellular IFN-γ production of T cells in stimulated peripheral blood mononuclear cells (PBMCs) was analyzed by flow cytometry using TB antigens (PPD), the polyclonal T cell activator staphylococcal enterotoxin B (SEB), or medium as unstimulated control. RESULTS: Helminth infected CCs and LTBI subjects showed a significant reduction of IFN-γ+ CD4+ T cells by PPD-stimulation compared to non-helminth infected control groups. The significant reduction in the frequency of IFN-γ+ T cells in both latent and active PTB patients following SEB stimulation was mostly attributed to Schistosoma mansoni infection, whereas Ascaris lumbricoides, Schistosoma mansoni, and hookworm infection contributed equally in CCs. Following anti-helminthic and anti-TB treatment for 2 months, the frequency of IFN-γ+ CD4 T cells in helminth coinfected PTB was restored to levels of helminth negative PTB before treatment. Helminth coinfected PTB patients with an intermediate and severe clinical course had reduced capacity for production of IFN-γ+ T cells compared to the corresponding non-helminth infected PTB. CONCLUSION: We found a reduction in IFN-γ producing T cells by helminth coinfection which was restored following anti-helminthic treatment. This reduction was helminth species-dependent in an exploratory sub-analysis and correlated to increased disease severity.

Accuracy of monocyte to lymphocyte ratio for tuberculosis diagnosis and its role in monitoring anti-tuberculosis treatment: Systematic review and meta-analysis.

BACKGROUND: High monocyte to lymphocyte ratio (MLR) values may be associated with the risk of active tuberculosis (TB) infection in adults, infants, and postpartum women with HIV infection. It may also serve as an indicator of the effectiveness of anti-TB treatment. Thus, the main aim of this study is to ascertain the accuracy of MLR for the diagnosis of TB and its role in monitoring the effectiveness of anti-TB therapy. METHODS: This systematic review and meta-analysis followed the preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. All statistical analyses were performed using STATA 11 and Meta-DiSc software. The Quality assessment of Diagnostic Accuracy Studies tool was used to evaluate the methodological quality of the included studies. The area under the hierarchical summary receiver-operating characteristic hierarchical summary ROC curve [(HSROC) curve (AUC)] was also calculated as an indicator of diagnostic accuracy. RESULTS: A total of 15 articles were included in this study. Accordingly, the result showed that elevated MLR is associated with increased risks of TB disease [odd ratio = 3.11 (95% CI: 1.40-6.93)]. The pooled sensitivity and specificity of MLR for identifying TB were 79.5% (95% CI: 68.5-87.3) and 80.2% (95% CI: 67.3-88.9), respectively. The AUC of HSROC was 0.88 (95% CI: 0.857-0.903), indicating the excellent diagnostic performance of MLR for TB. This study also showed that there is a significant reduction in the MLR value after anti-TB treatment in TB patients (standardized mean difference  = 0.68; 95% CI: 0.007, 1.43). CONCLUSIONS: Generally, MLR can be considered as a crucial biomarker to identify TB and monitor the effectiveness of anti-TB therapy.

Seroprevalence of HBV and HCV Among Diabetes Mellitus Patients Attending University of Gondar Hospital, Northwest Ethiopia.

BACKGROUND: Hepatitis B and hepatitis C viruses are common infections and main causative agents of chronic liver diseases, cirrhosis, and hepatocellular carcinoma. The liver is the major site of hormone and glucose metabolism which have deep interconnection with diabetes. Hepatitis-B and hepatitis-C virus infection and diabetes are prevalent diseases worldwide associated with increased morbidity and mortality. High prevalence of DM, HCV, and HBV showed that there is a higher chance of coexisting in an individual. Therefore, our study tried to assess the coexistence of hepatitis viruses and diabetes mellitus among DM patients at the University of Gondar comprehensive specialized hospital. METHODS: The hospital-based, cross-sectional study was conducted from November 01 to December 30, 2019 to as-sess the prevalence and associated factors of HBV and HCV among diabetes patients attending at University of Gondar referral hospital. Sociodemographic data was collected using a semi-structured questionnaire. Four milliliters of blood were collected using an anticoagulant free test tube for measurement of biochemical parameters and detection of hepatitis viruses. HBsAg and anti-HCV antibody detection was performed using One Step Cassette Style HBsAg Rapid Test and EUGENE® anti-HCV rapid test, respectively. Binary and multivariable logistic regression models were used to evaluate associated risk factors for the outcome variable. A p-value of < 0.05 was considered statistically significant. RESULTS: A total of 288 diabetes patients were included in this study and the prevalence of HBV and HCV was 7 (2.43%) and 18 (6.25%), respectively. Hepatitis B virus showed similar prevalence for type 1 and type 2 diabetes at 2.6% and 2.3%, respectively, but HCV showed a wide variation with 17.5% and 4.3% prevalence, respectively, for both diabetes types. In a multivariable logistic regression model compared with younger age (≤ 24 years), older age ≥ 65 years (AOR: 19.545, 95% CI: 2.577 - 22.827) age groups and poor glycemic control (AOR: 18.84, 95% CI: 17.83 - 20.39) showed significant association with HBV. CONCLUSIONS: A considerably large number of diabetes patients tested positive for anti-HCV antibody as a marker of Hepatitis C virus infection. None of the variables showed significant association with active Hepatitis B virus infection whereas older ages (≥ 65 years) and diabetes patients with poor glycemic control showed significant association with anti-HCV antibody positivity.

Helminth species dependent effects on Th1 and Th17 cytokines in active tuberculosis patients and healthy community controls.

Despite that the impact of different helminth species is not well explored, the current dogma states that helminths affect the Th1/Th2 balance which in turn affects the risk of tuberculosis (TB) reactivation and severity of disease. We investigated the influence of helminth species on cytokine profiles including IL-17A in TB patients and healthy community controls (CCs). In total, 104 newly diagnosed pulmonary TB patients and 70 HIV negative and QuantiFERON negative CCs in Gondar, Ethiopia were included following helminth screening by stool microscopy. Plasma samples and ex vivo stimulation of peripheral blood mononuclear cells (PBMCs) with purified protein derivative (PPD) and Staphylococcus enterotoxin B (SEB) was used to determine cytokine profiles by cytometric bead array. In CCs, Ascaris lumbricoides or Schistosoma mansoni infections were associated with an impaired Th1-type response (IFN-gamma, IL-6 and TNF-alpha) in PBMCs mainly with SEB stimulations, whereas in TB patients only hookworm infection showed a similar pattern. Among CCs, the IL-17A response in PBMCs stimulated with SEB was higher only for S. mansoni, whereas in TB patients, the elevated systemic IL-17A plasma level was significantly suppressed in hookworm infected TB patients compared to patients without helminth coinfection. Following treatment of TB and helminth infection there was a general decrease in ex vivio IL-10 and TNF-alpha production in unstimulated, PPD or SEB stimulated PBMCs that was the most pronounced and significant in TB patients infected with S. mansoni, whereas the follow-up levels of IFN-gamma and IL-17A was significantly increased only in TB patients without helminth coinfection from PBMCs stimulated mainly with SEB. In summary, in addition to confirming helminth specific effects on the Th1/Th2 response before and after TB treatment, our novel finding is that IL-17A was impaired in helminth infected TB patients especially for hookworm, indicating a helminth species-specific immunoregulatory effect on IL-17A which needs to be further investigated.

Aetiologies of acute undifferentiated febrile illness at the emergency ward of the University of Gondar Hospital, Ethiopia.

OBJECTIVE: Causes of acute febrile illness (AFI) often remain undetermined in developing countries, due to overlap of symptoms and limited available diagnostics. We aimed to assess the aetiology of AFI in adults in a referral hospital in northwest Ethiopia. METHODS: While all participants were tested for malaria by rapid diagnostic test (RDT), microscopy was only done on physician's request. Dengue virus (DENV) infections were detected using an RDT and ELISAs and dengue, yellow fever and chikungunya cases were identified by PCR. Bacterial aetiologies were investigated using blood culture and PCR. RESULTS: The aetiology of acute infection was identified for 20.5% of 200 patients enrolled. Eleven percent tested positive for Plasmodium, while microscopy was only requested for half of the identified malaria cases. For 4.0% of the Plasmodium-infected patients, an acute or past DENV (co-)infection was detected. We found 7.5% acute and 13.0% past DENV - all serotype 3 - infections. Bacterial infections were observed in 4.5% of the patients. CONCLUSION: Malaria is still a considerable aetiology of AFI and dengue is underrecognised. There are areas where both diseases occur concomitantly, and the DENV-3 serotype presumably spreads from Sudan to northern Ethiopia. As only 20.5% of the aetiologies were identified, a broader testing platform is required.

Differential effects of asymptomatic Ascaris lumbricoides, Schistosoma mansoni or hook worm infection on the frequency and TGF-beta-producing capacity of regulatory T cells during active tuberculosis.

Helminth induced expansion of regulatory T cells (Tregs) may take part in suppressing protective host responses during tuberculosis (TB), although Tregs functionality and link to TB disease severity remains unexplored. We investigated the species-specific effect of helminths on frequency and TGF-ß producing capacity of Tregs, and possible connection to TB disease severity. 89 pulmonary TB patients (PTB) and 69 community controls (CCs) from Gondar, Ethiopia, were included. Clinical disease severity was graded by TB score, and flow cytometry used to characterize Treg frequency and functionality measured as their TGF-ß-producing capacity. In helminth positive PTB patients (Helminth+PTB+) compared to helminth negative PTB or CCs, TGF-ß+ Tregs were significantly increased mainly in hookworm coinfection whereas S. mansoni increased TGF-ß+ Tregs in CCs. Treatment of TB and helminths decreased TGF-ß+ Tregs in Helminth+PTB+ at 2 months follow-up. There were no overall differences in the frequency of Tregs in CCs or PTB unless stratification on TB disease severity was performed. At inclusion Helminth+PTB+ had increased frequency of Tregs already at low disease severity, and TGF-ß+ Tregs correlated to intermediate-to-high disease severity. In conclusion, helminth specific increase of TGF-ß+ Tregs in PTB patients was correlated to TB disease severity and was restored following anti-helminth treatment.

Helminth species specific expansion and increased TNF-alpha production of non-classical monocytes during active tuberculosis.

Both Mycobacterium tuberculosis infection and helminths may affect innate immune mechanisms such as differential effects on monocytes towards the non-classical and intermediate subsets that favor bacterial persistence. Our aim, was to investigate helminth species specific effects on the frequency and functional activity of monocyte subsets in patients with active tuberculosis and healthy subjects. HIV-negative patients with active pulmonary tuberculosis (PTB) and community controls (CCs) in Gondar, Ethiopia were screened for helminth infection by stool microscopy. Flow cytometric analysis of peripheral blood mononuclear cells (PBMCs) and ex vivo stimulation with purified protein derivative (PPD) and helminth antigens were used to characterize the distribution of monocyte subsets and their function. A total of 74 PTB patients and 57 CCs with and without helminth infection were included. Non-classical monocytes were increased in PTB patients with Ascaris and hookworm infection but not in Schistosoma-infected patients. Ascaris had the strongest effect in increasing the frequency of non-classical monocytes in both PTB patients and CCs, whereas PTB without helminth infection did not affect the frequency of monocyte subsets. There was a helminth specific increase in the frequency of TNF-α producing non-classical monocytes in hookworm infected PTB patients, both with and without PPD-stimulation. Low-to-intermediate TB disease severity associated with increased frequency of non-classical monocytes only for helminth-positive PTB patients, and the frequency of TNF-α producing monocytes were significantly higher in intermediate and non-classical monocytes of helminth positive PTB patients with an intermediate disease score. Helminth infection affected the frequency of monocyte subsets and function both in TB patients and controls which was helminth species dependent in TB patients. The clinical role of this potential immunomodulatory effect needs further study and may affect the response and protection to tuberculosis in areas where helminth infections are endemic.

Evaluation of C-reactive protein and myxovirus resistance protein A to guide the rational use of antibiotics among acute febrile adult patients in Northwest Ethiopia.

OBJECTIVES: In low-resource settings, treatment is often given empirically without knowledge of the aetiology due to a lack of diagnostics. In the search for reliable rapid tests to guide treatment work-up, this study was performed to determine whether two biomarkers could differentiate bacterial from non-bacterial infections in acute febrile patients. METHODS: Adults with acute fever were recruited at a referral hospital in Ethiopia. The QuikRead Go test was used to quantify C-reactive protein (qCRP) and the FebriDx test was used for combined qualitative detection of the bacterial CRP marker with myxovirus resistance protein A (MxA), a viral biomarker. RESULTS: Of the 200 patients included in this study, most presented with 2-3 days of fever, headache, and joint pain. Antibiotics were prescribed for 83.5% and antimalarials for 36.5%, while a bacterial infection was only confirmed in 5% and malaria in 11%. The median qCRP level for confirmed bacterial infections was 128 mg/l. The FebriDx and QuikRead Go test had an overall agreement of 72.0%. CONCLUSIONS: An over-prescription of antibiotics for febrile patients was observed, even for those with low CRP levels and without a confirmed bacterial infection. The added value of the FebriDx was limited, while the combined use of rapid tests for qCRP and malaria should be considered for the management of acute febrile illness and antibiotic stewardship.

Latent tuberculosis infection and associated risk factors among people living with HIV and apparently healthy blood donors at the University of Gondar referral hospital, Northwest Ethiopia.

OBJECTIVE: Immuno-compromised individuals with latent tuberculosis infection (LTBI) are at an increased risk for tuberculosis reactivation compared with the general population. The aim of this study was to determine the prevalence of latent tuberculosis infection among people living with human immunodeficiency virus (PLWH) and apparently healthy blood donors. Human Immunodeficiency Virus positive individuals and for the purpose of comparison apparently healthy blood donors were enrolled. Blood sample was collected and tested for LTBI using QuantiFeron-TB Gold In-Tube assay (QFT-GIT) and CD4+ T cell count was determined by using BD FACS count. RESULTS: The overall prevalence of LTBI regardless of HIV status was 46%. The prevalence of LTBI among PLWH was 44% and that of blood donors 48%. ART naïve HIV positive patients were three times more likely to have LTBI than patients under ART treatment (P = 0.04). Data also showed statistically significant negative association between previous or current preventive INH therapy and LTBI among HIV positive cases (P = 0.005). The proportion of LTBI was slightly lower among HIV positive individuals than apparently healthy blood donors. Nevertheless, HIV positive individuals should be screened for LTBI and take INH prophylaxis.