Impaired Mycobacterium tuberculosis-specific T-cell memory phenotypes and functional profiles among adults with type 2 diabetes mellitus in Uganda.

Background: Efforts to eradicate tuberculosis (TB) are threatened by diabetes mellitus (DM), which confers a 3-fold increase in the risk of TB disease. The changes in the memory phenotypes and functional profiles of Mycobacterium tuberculosis (Mtb)-specific T cells in latent TB infection (LTBI)-DM participants remain poorly characterised. We, therefore, assessed the effect of DM on T-cell phenotype and function in LTBI and DM clinical groups. Methods: We compared the memory phenotypes and function profiles of Mtb-specific CD4+ and CD8+ T cells among participants with LTBI-DM (n=21), LTBI-only (n=17) and DM-only (n=16). Peripheral blood mononuclear cells (PBMCs) were stimulated with early secretory antigenic 6 kDa (ESAT-6) and culture filtrate protein 10 (CFP-10) peptide pools or phytohemagglutinin (PHA). The memory phenotypes (CCR7/CD45RA), and functional profiles (HLA-DR, PD-1, CD107a, IFN-γ, IL-2, TNF, IL-13, IL-17A) of Mtb-specific CD4+ and CD8+ T cells were characterised by flow cytometry. Results: Naïve CD4+ T cells were significantly decreased in the LTBI-DM compared to the LTBI-only participants [0.47 (0.34-0.69) vs 0.91 (0.59-1.05); (p<0.001)]. Similarly, CD8+ HLA-DR expression was significantly decreased in LTBI-DM compared to LTBI-only participants [0.26 (0.19-0.33) vs 0.52 (0.40-0.64); (p<0.0001)], whereas CD4+ and CD8+ PD-1 expression was significantly upregulated in the LTBI-DM compared to the LTBI-only participants [0.61 (0.53-0.77) vs 0.19 (0.10-0.28); (p<0.0001) and 0.41 (0.37-0.56) vs 0.29 (0.17-0.42); (p=0.007)] respectively. CD4+ and CD8+ IFN-γ production was significantly decreased in the LTBI-DM compared to the LTBI-only participants [0.28 (0.19-0.38) vs 0.39 (0.25-0.53); (p=0.030) and 0.36 (0.27-0.49) vs 0.55 (0.41-0.88); (p=0.016)] respectively. CD4+ TNF and CD8+ IL-17A production were significantly decreased in participants with LTBI-DM compared to those with LTBI-only [0.38 (0.33-0.50) vs 0.62 (0.46-0.87); (p=0.004) and 0.29 (0.16-0.42) vs 0.47 (0.29-0.52); (0.017)] respectively. LTBI-DM participants had significantly lower dual-functional (IFN-γ+IL-2+ and IL-2+TNF+) and mono-functional (IFN-γ+ and TNF+) CD4+ responses than LTBI-only participants. LTBI-DM participants had significantly decreased dual-functional (IFN-γ+IL-2+, IFN-γ+ TNF+ and IL-2+TNF+) and mono-functional (IFN-γ+, IL-2+ and TNF+) central and effector memory CD4+ responses compared to LTBI-only participants. Conclusion: Type 2 DM impairs the memory phenotypes and functional profiles of Mtb-specific CD4+ and CD8+ T cells, potentially indicating underlying immunopathology towards increased active TB disease risk.

Immunologic, metabolic and genetic impact of diabetes on tuberculosis susceptibility.

Due to the increasing prevalence of diabetes mellitus (DM) globally, the interaction between DM and major global diseases like tuberculosis (TB) is of great public health significance, with evidence of DM having about a three-fold risk for TB disease. TB defense may be impacted by diabetes-related effects on immunity, metabolism, and gene transcription. An update on the epidemiological aspects of DM and TB, and the recent trends in understanding the DM-associated immunologic, metabolic, and genetic mechanisms of susceptibility to TB will be discussed in this review. This review highlights gaps in the incomplete understanding of the mechanisms that may relate to TB susceptibility in type 2 DM (T2DM). Understanding these three main domains regarding mechanisms of TB susceptibility in T2DM patients can help us build practical treatment plans to lessen the combined burden of the diseases in rampant areas.

Increased Levels of Caspase-1 and IL-1ß Among Adults With Persistent Immune Activation After 12 Years of Suppressive Antiretroviral Therapy in the Infectious Diseases Institute HIV Treatment Cohort.

Background: We sought evidence of activated pyroptosis and the inflammasome pathways among human immunodeficiency virus (HIV)-infected adults after 12 years of suppressive antiretroviral therapy (ART) and persistent immune activation in the Infectious Diseases Institute HIV treatment cohort in Uganda. Methods: In a cross-sectional study, using peripheral blood mononuclear cells of HIV-infected individuals with high and low immune activation (CD4/CD8+CD38+HLA-DR+ cells) relative to HIV-negative reference group, caspase-1 expression was measured using flow cytometry and plasma interleukin 18 and interleukin 1ß (IL-1ß) levels using enzyme-linked immunosorbent assay. Results: There was higher expression of caspase-1 by CD4 T cells of ART-treated individuals with high immune activation relative to those with lower immune activation (P = .04). Similarly, plasma levels of IL-1ß were higher among ART-treated individuals with high immune activation levels relative to those with low immune activation levels (P = .009). We observed a low positive correlation between caspase-1 expression by CD4/CD8 T cells and immune activation levels (r= 0.497 and r= 0.329, respectively). Conclusions: Caspase-1 and IL-1ß were high among individuals with high immune activation despite 12 years of suppressive ART. There is a need to further understand the role of persistent abortive infection and the latent HIV reservoir characteristics as drivers of persistent activation and inflammation and to subsequently intervene to prevent the complications of chronic immune activation during long-term ART.

Effect of COVID-19 pandemic on inpatient service utilization and patient outcomes in Uganda.

COVID-19 has had devastating effects on health systems but reports from sub-Saharan Africa are few. We compared inpatient admissions, diagnostic tests performed, clinical characteristics and inpatient mortality before and during the COVID-19 pandemic at an urban tertiary facility in Uganda. We conducted a retrospective chart review of patients admitted at Kiruddu National Referral Hospital in Uganda between January-July 2019 (before the pandemic) and January-July 2020 (during the pandemic). Of 3749 inpatients, 2014 (53.7%) were female, and 1582 (42.2%) had HIV. There was a 6.1% decline in admissions from 1932 in 2019 to 1817 in 2020. There were significantly fewer diagnostic tests performed in 2020 for malaria, tuberculosis, and diabetes. Overall, 649 (17.3%) patients died. Patients admitted during the COVID-19 pandemic (adjusted odds ratio [aOR] 1.2, 95% confidence interval [CI] 1.04-1.5, p = 0.018), patients aged ≥ 60 years (aOR 1.6, 95% CI 1.2-2.1, p = 0.001), HIV co-infected (aOR 1.5, 95% CI 1.2-1.9, p < 0.001), and those admitted as referrals (aOR 1.5, 95% CI 1.2-1.9, p < 0.001) had higher odds of dying. The COVID-19 pandemic disrupted inpatient service utilization and was associated with inpatient mortality. Policy makers need to build resilience in health systems in Africa to cope with future pandemics.

Mycobacterium tuberculosis infection and cytogenetic abnormalities among people with HIV.

OBJECTIVE: To compare cytogenetic abnormalities among people living with HIV (PLWH) with and without previous exposure to Mycobacterium tuberculosis (Mtb) (both latent tuberculosis infection [LTBI] and active tuberculosis [TB]). METHODS: Adult PLWH (≥18 years) were randomly selected at three HIV clinics in Uganda. Previous active TB was confirmed in the clinics' TB records. LTBI was defined as a positive QuantiFERON-TB Gold Plus assay. Participants' buccal mucosal exfoliated cells were examined (per 2000 cells) using the buccal micronucleus assay for chromosomal aberrations (micronuclei and/or nuclear buds), cytokinetic defects (binucleated cells), proliferative potential (normal differentiated cells and basal cell frequency) and/or cell death (condensed chromatin, karyorrhexis, pyknotic and karyolytic cells). RESULTS: Among 97 PLWH, 42 (43.3%) had exposure to Mtb;16 had previous successfully treated active TB and 26 had LTBI. PLWH with exposure to Mtb had a higher median number of normal differentiated cells (1806.5 [1757.0 - 1842.0] vs. 1784.0 [1732.0 - 1843.0], p = 0.031) and fewer karyorrhectic cells (12.0 [9.0 - 29.0] vs. 18.0 [11.0 - 30.0], p = 0.048) than those without. PLWH with LTBI had fewer karyorrhectic cells than those without (11.5 [8.0 - 29.0] vs. 18.0 [11 - 30], p = 0.006). CONCLUSION: We hypothesized that previous exposure to Mtb is associated with cytogenetic damage among PLWH. We found that exposure to Mtb is associated with more normal differentiated cells and less frequent karyorrhexis (a feature of apoptosis). It is unclear whether this increases the propensity for tumorigenesis.

Burden and associated phenotypic characteristics of tuberculosis infection in adult Africans with diabetes: a systematic review.

Diabetes mellitus (DM) increases the risk of developing tuberculosis infection (TBI). However, the evidence on the burden and phenotypic characteristics of TBI in African patients with DM is limited. This study aimed to determine the prevalence and characterisation of TBI in native African patients living with DM. We searched PubMed, EMBASE, and African Journals Online for original studies reporting information on the prevalence and characteristics of TBI in adult Africans with DM. A forest plot was used to describe the pooled prevalence estimate of TBI and the corresponding 95% confidence intervals (CI). Six studies conducted in four African countries involving 721 participants with DM were included in this systematic review. The pooled prevalence estimate of TBI was 40% (95% CI 20-60%, I2 = 98.52%, p < 0.001). Age ≥ 40 years and glycated haemoglobin levels independently predicted TBI positivity in patients with DM in three studies. Africans with DM have a high prevalence of TBI, especially those who are older or with poorly controlled diabetes. This justifies the need for studies to explore how to screen and manage TBI to avert the progression to active TB disease.

HIV, tuberculosis, diabetes mellitus and hypertension admissions and premature mortality among adults in Uganda from 2011 to 2019: is the tide turning?

BACKGROUND: The growing burden of diabetes mellitus (DM) and hypertension (HTN) on the background of endemic Human Immuno-deficiency Virus (HIV) and tuberculosis (TB) is a concern in low- and middle-income countries. We aimed to describe annual trends in admissions, mortality rates and premature mortality (years of potential life lost-YPLLs) due to HIV, tuberculosis (TB), diabetes mellitus (DM) and hypertension (HTN) in Uganda. METHODS: We conducted a retrospective cohort study, retrieving electronic records of adults admitted to Mulago and Kiruddu national referral hospitals medical wards between 1st January 2011 and 31st December 2019. We used STATA BE 17.0 and GraphPad Prism 8.0.2 to compute total admissions, inpatient crude mortality rates, and YPLLs; and demonstrate trends using Mann-Kendall test. RESULTS: Of 108,357 admissions, 55,620 (51.3%) were female, 15,300 (14.1%) were recorded in 2012, and 22,997 (21.2%) were aged 21-30 years. HIV, TB, DM and HTN accounted for 26,021 (24.0%); 9537 (8.8%); 13,708 (12.7) and 13,252 (12.2%) of all admissions, respectively. Overall inpatient mortality was 16.7% (18,099/108,357), 53.5% (9674/18,099) were male, 21.5% (3898) were aged 31-40 years and 2597 (14.4%) were registered in 2013. HIV, TB, DM and HTN accounted for 35.6% (6444), 14.6% (2646), 9.1% (1648) and 11.8% (2142) of all deaths, respectively. Total admissions (Kendall's tau-B = - 0.833, p < 0.001) and deaths declined (Kendall's tau-B = - 0.611, p = 0.029). A total of 355,514 (mean = 20.8 years, SD 30.0) YPLLs were recorded, of which 54.6% (191,869) were in males; 36.2% (128,755) were among those aged 21-30 years and were recorded in 2012 (54,717; 15.4%). HIV, TB, DM and HTN accounted for 46.5% (165,352); 19.5% (69,347); 4.8% (16,991) and 4.5% (16,167) of YPLLs, respectively. Proportionate contribution of HIV to deaths and YPLLs declined, remained stagnant for TB; and increased for both DM and HTN. CONCLUSION: TB and HIV account for higher though declining, while DM and HTN account for lower albeit rising morbidity and premature mortality among adult medical patients in Uganda. TB prevention and treatment; and DM/HTN service integration in HIV care should be optimized and scaled up.

Indicators of optimal diabetes care and burden of diabetes complications in Africa: a systematic review and meta-analysis.

OBJECTIVE: Contemporary data on the attainment of optimal diabetes treatment goals and the burden of diabetes complications in adult populations with type 2 diabetes in Africa are lacking. We aimed to document the current status of attainment of three key indicators of optimal diabetes care and the prevalence of five diabetes complications in adult African populations with type 2 diabetes. METHODS: We systematically searched Embase, PubMed and the Cochrane library for published studies from January 2000 to December 2020. Included studies reported any information on the proportion of attainment of optimal glycated haemoglobin (HbA1c), blood pressure (BP) and low-density lipoprotein cholesterol (LDLC) goals and/or prevalence of five diabetes complications (diabetic peripheral neuropathy, retinopathy, nephropathy, foot ulcers and peripheral arterial disease). Random effect model meta-analysis was performed to determine the pooled proportion of attainment of the three treatment goals and the prevalence of five diabetes complications. RESULTS: In total, 109 studies with a total of 63 890 participants (53.3% being females) were included in the meta-analysis. Most of the studies were conducted in Eastern African countries (n=44, 40.4%). The pooled proportion of attainment of an optimal HbA1c, BP and LDLC goal was 27% (95% CI 24 to 30, I2=94.7%), 38% (95% CI 30 to 46, I2=98.7%) and 42% (95% CI 32 to 52, I2=97.4%), respectively. The pooled prevalence of diabetic peripheral neuropathy, retinopathy, diabetic nephropathy, peripheral arterial disease and foot ulcers was 38% (95% CI 31 to 45, I2=98.2%), 32% (95% CI 28 to 36, I2=98%), 31% (95% CI 22 to 41, I2=99.3%), 19% (95% CI 12 to 25, I2=98.1%) and 11% (95% CI 9 to 14, I2=97.4%), respectively. CONCLUSION: Attainment of optimal diabetes treatment goals, especially HbA1c, in adult patients with type 2 diabetes in Africa remains a challenge. Diabetes complications, especially diabetic peripheral neuropathy and retinopathy, are highly prevalent in adult populations with type 2 diabetes in Africa.

Anemia in Ugandan pregnant women: a cross-sectional, systematic review and meta-analysis study.

BACKGROUND: Anemia in pregnancy represents a global public health concern due to wide ranging maternal and neonatal adverse outcomes in all peripartum periods. We estimated the prevalence and factors associated with anemia in pregnancy at a national obstetrics and gynecology referral hospital in Uganda and in addition performed a systematic review and meta-analysis of the overall burden of anemia in pregnancy in Uganda. METHODS: We conducted a cross-sectional study among 263 pregnant women attending the antenatal care clinic of Kawempe National Referral Hospital, Kampala, Uganda, in September 2020. Anemia in pregnancy was defined as a hemoglobin level of < 11.0 g/dl and microcytosis as a mean corpuscular volume (MCV) of < 76 fL. We also performed a systematic review (PROSPERO Registration ID: CRD42020213001) and meta-analysis of studies indexed on MEDLINE, Embase, African Journal Online, ClinicalTrials.gov , ICTRP, and the Cochrane Library of systematic review between 1 January 2000 and 31 September 2020 reporting on the prevalence of anemia in pregnancy in Uganda. RESULTS: The prevalence of anemia was 14.1% (n= 37) (95%CI 10.4-18.8), of whom 21 (56.8%) had microcytic anemia. All cases of anemia occurred in the second or third trimester of pregnancy and none were severe. However, women with anemia had significantly lower MCV (75.1 vs. 80.2 fL, p<0.0001) and anthropometric measurements, such as weight (63.3 vs. 68.9kg; p=0.008), body mass index (25.2 vs. 27.3, p=0.013), hip (98.5 vs. 103.8 cm, p=0.002), and waist (91.1 vs. 95.1 cm, p=0.027) circumferences and mean systolic blood pressure (BP) (118 vs 125 mmHg, p=0.014). Additionally, most had BP within the normal range (59.5% vs. 34.1%, p=0.023). The comparison meta-analysis of pooled data from 17 published studies of anemia in pregnancy in Uganda, which had a total of 14,410 pregnant mothers, revealed a prevalence of 30% (95% CI 23-37). CONCLUSIONS: Despite our study having a lower prevalence compared to other studies in Uganda, these findings further confirm that anemia in pregnancy is still of public health significance and is likely to have nutritional causes, requiring targeted interventions. A larger study would be necessary to demonstrate potential use of basic clinical parameters such as weight or blood pressure as screening predictors for anemia in pregnancy.

Optimizing diabetes mellitus care to improve COVID-19 outcomes in resource-limited settings in Africa.

Diabetes mellitus (DM) is an important risk factor for both severe disease and death due to coronavirus-2019 (COVID-19). About 19 million of the 463 million persons living with DM (PLWD) globally are found in sub-Saharan Africa (SSA). The dual burden of DM and poverty in SSA, coupled with the rising number of cases of COVID-19 in this region, predisposes PLWD to inadequate care and poor glycemic controls due to the disruption to the economy and the healthcare system. The risk of acquisition of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) among PLWD is the same as those in the general population. Therefore, the standard preventive measures outlined by the World Health Organization must be strictly adhered to. In addition, maintaining adequate glycemic control is associated with better outcomes in DM patients with COVID-19. In SSA, adequate supply of DM medication while patients stay at home is crucial to minimize routine hospital visits since DM clinics are usually overcrowded and have longer waiting times, which may maximize risk of SARS-CoV-2 transmission to PLWD across the region. Psychosocial support to improve adherence to anti-hyperglycemic medications may improve COVID-19 outcomes. Trained healthcare professionals should diagnose and evaluate severity comprehensively as well as evaluate the need for in-patient care for PLWD with COVID-19 irrespective of disease severity. Due to the increased risk of severe disease, a multi-disciplinary approach to the management of COVID-19 in PLWD should preferably be in a setting where close monitoring is available, typically a health facility, even for mild disease that may require home management according to local guidelines. In conclusion, DM complicates COVID-19 outcomes and the on-going COVID-19 pandemic adversely affects DM care at individual and global public health levels. PLWD should be prioritized as COVID-19 vaccines are being rolled out.

Cryptococcosis complicating diabetes mellitus: a scoping review.

BACKGROUND: A better understanding of the epidemiology of cryptococcal infection in HIV-negative individuals is an international research interest. Immune dysfunction in diabetes mellitus (DM) significantly increases the risk of acquiring and reactivation of infection due to Cryptococcus neoformans. Risk factors and outcomes of cryptococcosis in DM are not well documented. OBJECTIVE: The objective of this study was to determine the clinical characteristics and outcomes of cryptococcal infections in persons living with DM. METHODS: MEDLINE (via PubMed), EMBASE, and the Cochrane Library databases were searched in November 2020. The searches covered the period between 1980 and 2020.We included studies that reported confirmed cryptococcosis in patients with DM. Reference lists of included articles were also searched, and additional studies were included if appropriate. No language restriction was applied. Single case reports, case series and original articles were included whereas review articles were excluded. RESULTS: A total of 28 studies (24 single case reports, 4 retrospectives) were included involving 47 unique patients from Asia (17 cases), North America (six cases), South America (three cases) and Africa (two cases). Men constituted 75% (n = 18) of the cases. Median age was 60.5 (range: 27-79) years. The majority of the patients had cryptococcal meningitis (68.1%, n = 32) followed by disseminated cryptococcosis (6.4%, n = 7), and others (isolated cutaneous disease one, peritonitis one, pleural one, thyroid one, adrenal one). Diagnosis was achieved through either culture and microscopy (38/47), cryptococcal antigen tests (9/47) or histopathology (9/47) singly or in a combination. All-cause mortality was 38.3% (n = 18). Among those with meningitis mortality was 36.2%. CONCLUSION: A wide spectrum of cryptococcal infections with varying severity occurs in DM. Mortality remains unacceptably high. There is a need for more studies to characterize better cryptococcal disease in DM.

Type 2 Diabetes Mellitus and Latent Tuberculosis Infection Moderately Influence Innate Lymphoid Cell Immune Responses in Uganda.

Background: Type 2 diabetes mellitus (T2DM) is a major risk factor for the acquisition of latent tuberculosis (TB) infection (LTBI) and development of active tuberculosis (ATB), although the immunological basis for this susceptibility remains poorly characterised. Innate lymphoid cells (ILCs) immune responses to TB infection in T2DM comorbidity is anticipated to be reduced. We compared ILC responses (frequency and cytokine production) among adult patients with LTBI and T2DM to patients (13) with LTBI only (14), T2DM only (10) and healthy controls (11). Methods: Using flow cytometry, ILC phenotypes were categorised based on (Lin-CD127+CD161+) markers into three types: ILC1 (Lin-CD127+CD161+CRTH2-CD117-); ILC2 (Lin-CD127+CD161+CRTH2+) and ILC3 (Lin-CD127+CD161+CRTH2-NKp44+/-CD117+). ILC responses were determined using cytokine production by measuring percentage expression of interferon-gamma (IFN-γ) for ILC1, interleukin (IL)-13 for ILC2, and IL-22 for ILC3. Glycaemic control among T2DM patients was measured using glycated haemoglobin (HbA1c) levels. Data were analysed using FlowJo version 10.7.1, and GraphPad Prism version 8.3. Results: Compared to healthy controls, patients with LTBI and T2DM had reduced frequencies of ILC2 and ILC3 respectively (median (IQR): 0.01 (0.005-0.04) and 0.002 (IQR; 0.002-0.007) and not ILC1 (0.04 (0.02-0.09) as expected. They also had increased production of IFN-γ [median (IQR): 17.1 (5.6-24.9)], but decreased production of IL-13 [19.6 (12.3-35.1)]. We however found that patients with T2DM had lower ILC cytokine responses in general but more marked for IL-22 production (median (IQR): IFN-γ 9.3 (4.8-22.6); IL-13 22.2 (14.7-39.7); IL-22 0.7 (IQR; 0.1-2.1) p-value 0.02), which highlights the immune suppression status of T2DM. We also found that poor glycaemic control altered ILC immune responses. Conclusion: This study demonstrates that LTBI and T2DM, and T2DM were associated with slight alterations of ILC immune responses. Poor T2DM control also slightly altered these ILC immune responses. Further studies are required to assess if these responses recover after treatment of either TB or T2DM.

Latent Tuberculosis Infection Status of Pregnant Women in Uganda Determined Using QuantiFERON TB Gold-Plus.

BACKGROUND: The risk of progression of latent tuberculosis infection (LTBI) to active disease increases with pregnancy. This study determined the prevalence and risk factors associated with LTBI among pregnant women in Uganda. METHODS: We enrolled 261 pregnant women, irrespective of gestational age. Participants who had known or suspected active tuberculosis (TB) on the basis of clinical evaluation or who had recently received treatment for TB were excluded. LTBI was defined as an interferon-γ concentration ≥0.35 IU/mL (calculated as either TB1 [eliciting CD4+ T-cell responses] or TB2 [eliciting CD8+ T-cell responses] antigen minus nil) using QuantiFERON TB Gold-Plus (QFT-plus) assay. RESULTS: LTBI prevalence was 37.9% (n = 99) (95% confidence interval [CI], 32.3-44.0). However, 24 (9.2%) subjects had indeterminate QFT-plus results. Among participants with LTBI, TB1 and TB2 alone were positive in 11 (11.1%) and 18 (18.2%) participants, respectively. In multivariable analysis, human immunodeficiency virus (HIV) infection (adjusted odds ratio [aOR], 4.4 [95% confidence interval {CI}, 1.1-18.0]; P = .04) and age 30-39 years (aOR, 4.0 [95% CI, 1.2-12.7]; P = .02) were independently associated with LTBI. Meanwhile, smoking status, alcohol use, nature of residence, crowding index, and TB contact were not associated with LTBI. CONCLUSIONS: Our findings are in keeping with the evidence that HIV infection and advancing age are important risk factors for LTBI in pregnancy. In our setting, we recommend routine screening for LTBI and TB preventive therapy among eligible pregnant women.