Non-specific immunity of BCG vaccine: A perspective of BCG immunotherapy

AbstractBCG is a widely used vaccine worldwide for neonates including Pakistan. BCG has more than 90% coverage through the EPI program which was introduced in 1965 in Pakistan. BCG has limited efficacy against the transmissible form of pulmonary tuberculosis in high TB endemic countries. However, BCG vaccination continues in these countries because BCG confers protection against the disseminated form of TB in children. BCG has also shown some protection against leprosy and certain forms of cancers. One reason for such nonspecific protection may be that BCG activates APCs via PAMPS that interacts with TLRs (2, 4 & 8), which initiate the inflammatory cascade thereby recruiting inflammatory cells to the site of infection and providing maturation signals for neutrophils, macrophages and dendritic cells. Such activation may be crucial for restricting the infection at the initial site. Furthermore, activation of the pro-inflammatory cascade also results in expression of adhesion molecules, co-stimulatory molecules as well as MHC class II molecule. MHC class II molecules engage CD4+ cells via the TCR receptor while the adhesion and costimulatory molecules bind to their respective receptors on CD4+ T cells for additional high affinity binding for T cell activation. Although activation of the innate arm may not provide subsequent memory, activation of T cells may introduce a certain level of memory response and therefore, may form a rational basis for BCG immunotherapy. This review, therefore, focuses on the immune activation related to both the innate and adaptive arm of the immune response that has been reported and further explores the utility of BCG immunotherapy related to non TB conditions

FSH/LH ratio in females and intracytoplasmic sperm injection

Objective: To observe the effect of follicle stimulating hormone-luteinizing hormone ratio on oocyte parameters, quality of embryo, implantation and clinical pregnancy rate after intracytoplasmic sperm injection.Methods: The retrospective study was conducted at a fertility clinic in Islamabad, Pakistan, and comprised data of primary infertile females who underwent intracytoplasmic sperm injection from June 2011 to March 2013. All subjects had duration of infertility more than two years, and age range was 20-40 years. Follicle stimulating hormone and luteinizing hormone were estimated by enzyme-linked immunosorbent assay on day 3 of the cycle and the ratio was calculated. Groups were stratified on the basis of median ratio into groups I 1.26. SPSS 20 was used for data analysis.Results: Of the 282 females, 143(51%) were in group I and 139(49%) in group II. Pregnancy was acquired by 79(55%) and 22(16%) females in group I and II respectively. The number of retrieved, metaphase, fertilised oocytes, cleaved embryos and endometrial thickness was significantly larger in group I (p\u3c 0.0001).Conclusions: Follicle stimulating hormone-luteinizing hormone ratio less than 1.26 was associated with good oocyte parameters, top quality embryo and implantation after intracytoplasmic sperm injection

Role of oxidative stress and altered thyroid hormones in unexplained infertility

Objective: To explore the link between altered thyroid profile and oxidative stress marker in females with unexplained infertility.Methods: The cross-sectional case-control study was carried out at the Islamabad Clinic Serving Infertile Couples, Islamabad, Pakistan, from June 2016 to August 2017, and comprised women aged 18-40 years regardless of ethnic background who were divided into two groups; those with unexplained infertility were the cases, while fertile women acted as the controls. Serum was analysed for triiodothyronine, thyroxine and thyroid stimulating hormone as well as for oxidative stress markers including manganese superoxide dismutase, glutathione reductase and adrenaline using enzymelinked immunosorbent assay. Data was analysed using SPSS 19.Results: Of the 88 subjects, there were 44(50%) in each of the two groups. There was no significant difference in terms of thyroids markers except thyroxine and thyroid stimulating hormone (p\u3c0.05). There were significant differences in terms of oxidative stress markers between the groups (p\u3c0.05). A significant positive correlation of thyroid stimulating hormone was observed with manganese superoxide dismutase and adrenaline (p\u3c0.05) with a weak non significant association of glutathione reductase (p\u3e0.05).Conclusions: Increased thyroxine levels in females with unexplained infertility was associated with decrease in the serum levels of antioxidants

Interplay of chemo attractant peptides (cathelicidin and chemerin) with vitamin-D in patients with pulmonary tuberculosis

Aim: Both Cathelicidin and Chemerin are chemoattractant proteins and possess antimicrobial activity.Sufficient level of Vitamin D is important for optimum response of Cathelicidin for its antimycobacterial activity. Studies on the role of these antimicrobial peptides and their relationship withVitamin D level are limited in tuberculosis. The aim of this study was to investigate an associationof Vitamin D with antimicrobial peptide (Cathelicidin) and an adipokine (Chemerin) in patients with pulmonary tuberculosis (TB). Methods: In a case control study we estimated level of Vitamin D, Chemerin, Cathelicidin and TNFα in pulmonary TB patients (n=22) and healthy endemic controls (n=17) using sandwich ELISA methodology. The study was conducted at Aga Khan University Karachi during 2011. Results: TB group had higher proportion of subjects above median level of Cathelicidin (median test; p=0.034) and fewer number of subjects with Chemerin (median test; p=0.001).Pairwise comparison also showed significant differences between average ranks of Vitamin D vs.Cathelicidin (p\u3c0.0001), Chemerin vs. Cathelicidin (p=0.04) and Vitamin D vs.TNFα(p\u3c0.0001). Cathelicidin was identified as most discriminatory marker between TB disease and healthy group(ROC,AUC 0.780; p=0.007). Conclusion: Our results highlight the role of Cathelicidin as a potential biomarker of active TB disease. The role of Cathelicidin and Chemerin as plausible biomarkers requires further studies in both inflammatory and non inflammatory condition

Mucosal genomics implicate lymphocyte activation and lipid metabolism in refractory environmental enteric dysfunction

Background & aims: Environmental enteric dysfunction (EED) limits the Sustainable Development Goals of improved childhood growth and survival. We applied mucosal genomics to advance our understanding of EED.Methods: The Study of Environmental Enteropathy and Malnutrition (SEEM) followed 416 children from birth to 24 months in a rural district in Pakistan. Biomarkers were measured at 9 months and tested for association with growth at 24 months. The duodenal methylome and transcriptome was determined in 52 undernourished SEEM participants and 42 North American controls and celiac disease patients.Results: After accounting for growth at study entry, circulating IGF-1 and ferritin predicted linear growth, whereas leptin correlated with future weight gain. The EED transcriptome exhibited suppression of antioxidant, detoxification, and lipid metabolism genes, and induction of anti-microbial response, interferon, and lymphocyte activation genes. Relative to celiac disease, suppression of antioxidant and detoxification genes and induction of anti-microbial response genes were EED-specific. At the epigenetic level, EED showed hyper-methylation of epithelial metabolism and barrier function genes, and hypo-methylation of immune response and cell proliferation genes. Duodenal co-expression modules showed association between lymphocyte proliferation and epithelial metabolic genes and histologic severity, fecal energy loss, and wasting (weight-for-length/height Z\u3c-2.0). Leptin was associated with expression of epithelial carbohydrate metabolism and stem cell renewal genes. Immune response genes were attenuated by giardia colonization.Conclusions: Children with reduced circulating IGF-1 are more likely to experience stunting. Leptin and a gene signature for lymphocyte activation and dysregulated lipid metabolism are implicated in wasting, suggesting new approaches for EED refractory to nutritional intervention

Comparing growth velocity of HIV exposed and non-exposed infants: An observational study of infants enrolled in a randomized control trial in Zambia

Background: Impaired growth among infants remains one of the leading nutrition problems globally. In this study, we aimed to compare the growth trajectory rate and evaluate growth trajectory characteristics among children, who are HIV exposed uninfected (HEU) and HIV unexposed uninfected (HUU), under two years in Zambia.Method: Our study used data from the ROVAS II study (PACTR201804003096919), an open-label randomized control trial of two verses three doses of live, attenuated, oral RotarixTM administered 6 &10 weeks or at 6 &10 weeks plus an additional dose at 9 months of age, conducted at George clinic in Lusaka, Zambia. Anthropometric measurements (height and weight) were collected on all scheduled and unscheduled visits. We defined linear growth velocity as the rate of change in height and estimated linear growth velocity as the first derivative of the mixed effect model with fractional polynomial transformations and, thereafter, used the second derivative test to determine the peak height and age at peak heigh.Results: We included 212 infants in this study with median age 6 (IQR: 6-6) weeks of age. Of these 97 (45.3%) were female, 35 (16.4%) were stunted, and 59 (27.6%) were exposed to HIV at baseline. Growth velocity was consistently below the 3rd percentile of the WHO linear growth standard for HEU and HUU children. The peak height and age at peak height among HEU children were 74.7 cm (95% CI = 73.9-75.5) and 15.5 months (95% CI = 14.7-16.3) respectively and those for HUU were 73 cm (95% CI = 72.1-74.0) and 15.6 months (95% CI = 14.5-16.6) respectively.Conclusion: We found no difference in growth trajectories between infants who are HEU and HUU. However, the data suggests that poor linear growth is universal and profound in this cohort and may have already occurred in utero

Performance of machine learning classifiers in classifying stunting among under-five children in Zambia

Stunting is a global public health issue. We sought to train and evaluate machine learning (ML) classification algorithms on the Zambia Demographic Health Survey (ZDHS) dataset to predict stunting among children under the age of five in Zambia. We applied Logistic regression (LR), Random Forest (RF), SV classification (SVC), XG Boost (XgB) and Naïve Bayes (NB) algorithms to predict the probability of stunting among children under five years of age, on the 2018 ZDHS dataset. We calibrated predicted probabilities and plotted the calibration curves to compare model performance. We computed accuracy, recall, precision and F1 for each machine learning algorithm. About 2327 (34.2%) children were stunted. Thirteen of fifty-eight features were selected for inclusion in the model using random forest. Calibrating the predicted probabilities improved the performance of machine learning algorithms when evaluated using calibration curves. RF was the most accurate algorithm, with an accuracy score of 79% in the testing and 61.6% in the training data while Naïve Bayesian was the worst performing algorithm for predicting stunting among children under five in Zambia using the 2018 ZDHS dataset. ML models aids quick diagnosis of stunting and the timely development of interventions aimed at preventing stunting

Study of environmental enteropathy and malnutrition (SEEM) in Pakistan: protocols for biopsy based biomarker discovery and validation

Background: Environmental Enteropathy (EE), characterized by alterations in intestinal structure, function, and immune activation, is believed to be an important contributor to childhood undernutrition and its associated morbidities, including stunting. Half of all global deaths in children \u3c 5 years are attributable to under-nutrition, making the study of EE an area of critical priority. Methods: Community based intervention study, divided into two sub-studies, 1) Longitudinal analyses and 2) Biopsy studies for identification of EE features via omics analyses. Birth cohorts in Matiari, Pakistan established: moderately or severely malnourished (weight for height Z score (WHZ) \u3c − 2) children, and well-nourished (WHZ \u3e 0) children. Blood, urine, and fecal samples, for evaluation of potential biomarkers, will be collected at various time points from all participants (longitudinal analyses). Participants will receive appropriate educational and nutritional interventions; non-responders will undergo further evaluation to determine eligibility for further workup, including upper gastrointestinal endoscopy. Histopathological changes in duodenal biopsies will be compared with duodenal biopsies obtained from USA controls who have celiac disease, Crohn’s disease, or who were found to have normal histopathology. RNA-Seq will be employed to characterize mucosal gene expression across groups. Duodenal biopsies, luminal aspirates from the duodenum, and fecal samples will be analyzed to define microbial community composition (omic analyses). The relationship between histopathology, mucosal gene expression, and community configuration will be assessed using a variety of bioinformatic tools to gain better understanding of disease pathogenesis and to identify mechanism-based biomarkers. Ethical review committees at all collaborating institutions have approved this study. All results will be made available to the scientific community. Discussion: Operational and ethical constraints for safely obtaining intestinal biopsies from children in resource-poor settings have led to a paucity of human tissue-based investigations to understand and reverse EE in vulnerable populations. Furthermore, EE biomarkers have rarely been correlated with gold standard histopathological confirmation. The Study of Environmental Enteropathy and Malnutrition (SEEM) is designed to better understand the pathophysiology, predictors, biomarkers, and potential management strategies of EE to inform strategies to eradicate this debilitating pathology and accelerate progress towards the 2030 Sustainable Development Goals. Trial registration: Retrospectively registered; clinicaltrials.gov ID NCT03588013

Use of quantitative molecular diagnostic methods to investigate the effect of enteropathogen infections on linear growth in children in low-resource settings: Longitudinal analysis of results from the MAL-ED cohort study

Background: Enteropathogen infections in early childhood not only cause diarrhoea but contribute to poor growth. We used molecular diagnostics to assess whether particular enteropathogens were associated with linear growth across seven low-resource settings.Methods: We used quantitative PCR to detect 29 enteropathogens in diarrhoeal and non-diarrhoeal stools collected from children in the first 2 years of life obtained during the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) multisite cohort study. Length was measured monthly. We estimated associations between aetiology-specific diarrhoea and subclinical enteropathogen infection and quantity and attained length in 3 month intervals, at age 2 and 5 years, and used a longitudinal model to account for temporality and time-dependent confounding. Findings: Among 1469 children who completed 2 year follow-up, 35622 stool samples were tested and yielded valid results. Diarrhoeal episodes attributed to bacteria and parasites, but not viruses, were associated with small decreases in length after 3 months and at age 2 years. Substantial decrements in length at 2 years were associated with subclinical, non-diarrhoeal, infection with Shigella (length-for-age Z score [LAZ] reduction –0·14, 95% CI –0·27 to –0·01), enteroaggregative Escherichia coli (–0·21, –0·37 to –0·05), Campylobacter (–0·17, –0·32 to –0·01), and Giardia (–0·17, –0·30 to –0·05). Norovirus, Cryptosporidium, typical enteropathogenic E coli, and Enterocytozoon bieneusi were also associated with small decrements in LAZ. Shigella and E bieneusi were associated with the largest decreases in LAZ per log increase in quantity per g of stool (–0·13 LAZ, 95% CI –0·22 to –0·03 for Shigella; –0·14, –0·26 to –0·02 for E bieneusi). Based on these models, interventions that successfully decrease exposure to Shigella, enteroaggregative E coli, Campylobacter, and Giardia could increase mean length of children by 0·12–0·37 LAZ (0·4–1·2 cm) at the MAL-ED sites.Interpretation: Subclinical infection and quantity of pathogens, particularly Shigella, enteroaggregative E coli, Campylobacter, and Giardia, had a substantial negative association with linear growth, which was sustained during the first 2 years of life, and in some cases, to 5 years. Successfully reducing exposure to certain pathogens might reduce global stunting

Bile acid profiling reveals distinct signatures in undernourished children with environmental enteric dysfunction

Background: Intestinal inflammation and malabsorption in environmental enteric dysfunction (EED) are associated with early childhood growth faltering in impoverished settings worldwide.Objectives: The goal of this study was to identify candidate biomarkers associated with inflammation, EED histology, and as predictors of later growth outcomes by focusing on the liver-gut axis by investigating the bile acid metabolome.Methods: Undernourished rural Pakistani infants (n = 365) with weight-for-height Z score (WHZ) \u3c -2 were followed up to the age of 24 mo and monitored for growth, infections, and EED. Well-nourished local children (n = 51) were controls, based on consistent WHZ \u3e 0 and height-for-age Z score (HAZ) \u3e -1 on 2 consecutive visits at 3 and 6 mo. Serum bile acid (sBA) profiles were measured by tandem MS at the ages of 3-6 and 9 mo and before nutritional intervention. Biopsies and duodenal aspirates were obtained following upper gastrointestinal endoscopy from a subset of children (n = 63) that responded poorly to nutritional intervention. BA composition in paired plasma and duodenal aspirates was compared based on the severity of EED histopathological scores and correlated to clinical and growth outcomes.Results: Remarkably, \u3e70% of undernourished Pakistani infants displayed elevated sBA concentrations consistent with subclinical cholestasis. Serum glycocholic acid (GCA) correlated with linear growth faltering (HAZ, r = -0.252 and -0.295 at the age of 3-6 and 9 mo, respectively, P Conclusions: Dysregulated bile acid metabolism is associated with growth faltering and EED severity in undernourished children. Restoration of intestinal BA homeostasis may offer a novel therapeutic target for undernutrition in children with EED. This trial was registered at clinicaltrials.gov as NCT03588013