Immunologic risk factors for early mortality after starting antiretroviral therapy in HIV-infected Zambian children

The under reporting of recruitment strategies in research with children with life-threatening illnesses: A systematic review

BACKGROUND

Researchers report difficulties in conducting research with children and young people with life-limiting conditions or life-threatening illnesses and their families. Recruitment is challenged by barriers including ethical, logistical and clinical considerations.

AIM

To explore how children and young people (aged 0-25 years) with life-limiting conditions or life-threatening illnesses and their families were identified, invited and consented to research published in the last 5 years.

DESIGN

Systematic review.

DATA SOURCES

MEDLINE, PsycINFO, Web of Science, Sciences Citation Index and SCOPUS were searched for original English language research published between 2009 and 2014, recruiting children and young people with life-limiting conditions or life-threatening illness and their families.

RESULTS

A total of 215 studies - 152 qualitative, 54 quantitative and 9 mixed methods - were included. Limited recruitment information but a range of strategies and difficulties were provided. The proportion of eligible participants from those screened could not be calculated in 80% of studies. Recruitment rates could not be calculated in 77%. A total of 31% of studies recruited less than 50% of eligible participants. Reasons given for non-invitation included missing clinical or contact data, or clinician judgements of participant unsuitability. Reasons for non-participation included lack of interest and participants' perceptions of potential burdens.

CONCLUSION

All stages of recruitment were under reported. Transparency in reporting of participant identification, invitation and consent is needed to enable researchers to understand research implications, bias risk and to whom results apply. Research is needed to explore why consenting participants decide to take part or not and their experiences of research recruitment.

Predictors of mortality among HIV-infected children receiving highly active antiretroviral therapy

BACKGROUND AND OBJECTIVES

The mortality rate of HIV-infected children can be reversed under highly active antiretroviral therapy (HAART). The impact of HAART on the mortality of HIV-infected children in Cameroon has not been extensively documented. We aimed to measure the mortality rate of HIV-infected children under HAART and to identify predictive factors of mortality.

METHODS

Retrospective cohort study of 221 children initiated on HAART from 2005 to 2009 and followed-up until 2013. Survival data was analyzed using Kaplan Meier method and Cox regression model to identify independent predictors of child mortality on HAART.

RESULTS

Overall, 9.9% of children (n=22) died over a follow-up period of 755 child-years (mortality of 2.9 per 100 child-years); 70% of deaths occurred during the first six months of HAART. The probability of survival after four years of treatment was 88.7% (95% CI=[84.2-93.3]). During the multivariate analysis of baseline variables, we observed that the WHO clinical stages III and IV (HR: 3.55 [1.09-13.6] and HR: 7.7 [3.07-31.2]) and age≤1year at HAART initiation were independently associated with death (HR: 2.1 [1.01-5.08]). Neither orphanhood, baseline CD4 count or hemoglobin level nor low nutritional status predicted death in this cohort.

CONCLUSION

The mortality of children receiving HAART was low after five years of follow-up and it was strongly associated with WHO stages III and IV and a younger age at treatment initiation.

Predictors of Mortality and Mortality Rate in a Cohort of Children Living with HIV from India

OBJECTIVES

To study the predictors of mortality and mortality rate in a clinical cohort of Children Living with Human Immunodeficiency Virus infection (CLHIV) from India.

METHODS

This retrospective cohort analysis of CLHIV aged between 2 mo and 18 y registered during January 2004 through December 2014 at Pediatric Centre of Excellence (PCOE), Indira Gandhi Institute of Child Health (IGICH), was conducted using standard data collection sheet. Demographic and clinical characteristics of all eligible children were analyzed. The primary outcome measured was mortality. The authors also analyzed the cause of death and baseline parameters associated with death to study the predictors of mortality.

RESULTS

Out of 1289 CLHIV registered in the PCOE during the study period, 834 (64.7 %) CLHIV, with or without antiretroviral therapy (ART) care, were included. The total time contributed by the study participants was 2872.8 child-years. The mortality rate in these children was 4.9/100 child-years. A significantly higher mortality rate of 28.2 % was found in children < 5 y, 38.6 % in children with advanced WHO clinical staging, 35.2 % among severely immunosuppressed children and 22.3 % in severely malnourished children. Tuberculosis accounted for 28 % of deaths. Univariate Cox regression analysis showed treatment status, age <5 y, baseline WHO clinical stage 3 and 4, severe immune suppression and severe malnutrition were strongly associated with mortality.

CONCLUSIONS

The mortality rate in the index study cohort was 4.9/100 child-years and tuberculosis was the major cause of death. Younger age, baseline advanced clinical and immunological staging were predictors of mortality. Even though mortality was significantly higher in Pre-ART children, treatment status was not found to be an independent predictor of mortality.

T cell subset profile in healthy Zambian adults at the University Teaching Hospital

Introduction

Symptom-free human immunodeficiency virus antibody-negative Zambian adults (51 subjects, aged 20 to 62 years, 33.3% women and 66.7% men) were studied to establish T cell subset reference ranges.

Methods

We carried out across sectional study at the University Teaching Hospital, Lusaka. Blood samples were collected from healthy donor volunteers from hospital health care staff, between February and March 2015. Immunopheno typing was undertaken to characterize Tcell subsets using the markers CD3, CD4, CD8, α4β7, Ki67, CD25, CCR7, CD54RA, CD57, CD28, CD27 and HLA-DR.

Results

Among 51 volunteers, Women had significantly higher absolute CD4 count (median 1042; IQR 864, 1270) than in men (671; 545, 899) (p=0.003). Women also had more CD4 cells expressing homing, naïve, effector and effector memory T cell subsets compared to men. However, in the CD8 population, only the effector cells were significantly different with women expressing more than the males.

Conclusion

We provide early reference range for T cell subsets in Zambian adults and conclude that among the African women some T cell subsets are higher than men.

T-Cell Subsets Predict Mortality in Malnourished Zambian Adults Initiating Antiretroviral Therapy

OBJECTIVE

To estimate the prognostic value of T-cell subsets in Zambian patients initiating antiretroviral therapy (ART), and to assess the impact of a nutritional intervention on T-cell subsets.

METHODS

This was a sub-study of a randomised clinical trial of a nutritional intervention for malnourished adults initiating ART. Participants in a randomised controlled trial (NUSTART trial) were enrolled between April and December 2012. Participants received lipid-based nutritional supplement either with or without additional vitamins and minerals. Immunophenotyping was undertaken at baseline and, in survivors, after 12 weeks of ART to characterize T-cell subsets using the markers CD3, CD4, CD8, CD45RA, CCR7, CD28, CD57, CD31, α4β7, Ki67, CD25 and HLA-DR. Univariate and multivariate survival analysis was performed, and responses to treatment were analysed using the Wicoxon rank-sum test.

RESULTS

Among 181 adults, 36 (20%) died by 12 weeks after starting ART. In univariate analysis, patients who died had fewer proliferating, more naïve and fewer gut homing CD4+ T-cells compared to survivors; and more senescent and fewer proliferating CD8+ T-cells. In a multivariate Cox regression model high naïve CD4+, low proliferating CD4+, high senescent CD8+ and low proliferating CD8+ subsets were independently associated with increased risk of death. Recent CD4+ thymic emigrants increased less between recruitment and 12 weeks of ART in the intervention group compared to the control group.

CONCLUSIONS

Specific CD4+ T-cell subsets are of considerable prognostic significance for patients initiating ART in Zambia, but only thymic output responded to this nutritional intervention.

Changes in cellular immune activation and memory T-cell subsets in HIV-infected Zambian children receiving HAART

BACKGROUND

Increased exposure to a broad array of pathogens in children residing in sub-Saharan Africa may lead to heightened immune activation and increased proportions of memory T cells. Changes in the size of these cellular subsets have implications for restoration of normal immune function after treatment with highly active antiretroviral therapy (HAART) and are not well characterized in young sub-Saharan African children.

METHODS

CD4⁺ and CD8⁺ T-cell subsets were measured by flow cytometry in 157 HIV-infected Zambian children before and at 3-month intervals during HAART for up to 30 months and in 34 control children at a single study visit.

RESULTS

Before HAART, HIV-infected children had higher levels of activated and effector memory (EM) CD4⁺ and CD8⁺ T cells, and lower levels of naive T cells and CD8⁺ T cells expressing IL-7Rα, compared with control children. The median duration of follow-up was 14.9 months (interquartile range, 6.4-23.2) among 120 HIV-infected children with at least 1 study follow-up visit. Levels of immune activation and EM CD4⁺ T cells declined within 6 months of HAART, but the percentages of EM CD4 T cells and effector CD8⁺ T cells remained elevated through 30 months of HAART. IL-7Rα-expressing CD8⁺ T cells increased with HAART, suggesting expansion of memory capacity.

CONCLUSIONS

HAART significantly reduced levels of immune activation and EM CD4⁺ T cells, and promoted reconstitution of naive T cells and IL-7Rα-expressing CD8⁺ T cells. However, persistently high levels of EM CD4⁺ T cells in HIV-infected children may reflect chronic perturbations in T-cell subset composition.

Antiretroviral therapy restores age-dependent loss of resting memory B cells in young HIV-infected Zambian children

BACKGROUND

Antiretroviral therapy (ART) is associated with incomplete restoration of resting memory B (RMB) cell percentages in adults infected with HIV, but the effects on RMB cells in children are less well defined, in part because changes in RMB cell percentages are confounded by the development and maturation of the RMB cell pool. The objective of this study was to assess the effect of age at ART initiation on RMB cell percentages over time in HIV-infected Zambian children.

METHODS

RMB cell percentages (CD19CD21CD27) were measured by flow cytometry in 146 HIV-infected Zambian children (9-120 months old) at baseline and at 3-month intervals after ART initiation and in 34 control children at a single study visit.

RESULTS

RMB cell percentages among untreated HIV-infected children younger than 24 months did not differ from those of control children (P = 0.97). Among HIV-infected children older than 24 months of age, however, each 12-month increase in age at ART initiation was associated with a 1.8% decrease in RMB cell percentage. In contrast, RMB cell percentages in control children up to 48 months increased 4.4% with each 12-month increase in age. After 12 months of ART, children aged 24-60 months had a significant increase in RMB cell percentages that no longer differed from those of control children.

CONCLUSIONS

Initiation of ART in 2- to 5-year-old HIV-infected children resulted in reconstitution of RMB cell percentages to levels similar to control children and may help restore normal development and maintenance of B-cell immunity.