Peripheral-blood cytopenia, an early indicator of inborn errors of immunity.

Inborn errors of immunity (IEI) are inherited monogenic disorders resulting in defective immune response. Non-infectious presentations are increasingly more apparent. Widely available, cost-effective early indicators are needed. Peripheral-blood cytopenia may be a presenting laboratory feature or an observed secondary phenomenon. This retrospective review of the South African Primary Immunodeficiency Registry (SAPIDR) aimed to assess the haematological indices at presentation and their association with the International Union of Immunological Societies (IUIS) 2019 IEI classification and mortality. Of 396 patients on the SAPIDR, 66% (n = 257) had available haematological results. Sixty percent were males and 85% under 18 years. A majority (53%) had predominantly antibody deficiency. At presentation, infection was prominent (86%) followed by cytopenia (62%). Neutropenia was associated with IUIS III [odds ratio (OR) 3.65, confidence interval (CI) 1.44-9.25], thrombocytopenia with IUIS II (OR 14.39, CI 2.89-71.57), lymphopenia with IUIS I (OR 12.16, CI 2.75-53.73) and pancytopenia with IUSI I (OR 12.24, CI 3.82-39.05) and IUIS II (OR 5.99, CI 2.80-12.76). Cytopenia showed shorter overall survival (OR 2.81, CI 1.288-4.16). Cytopenias that are severe, persistent, unusual and/or recurrent should prompt further investigation for IEI. The full blood count and leucocyte differential may facilitate earlier identification and serve as an adjunct to definitive molecular classification.

Phenotypic and immune functional profiling of patients with suspected Mendelian Susceptibility to Mycobacterial Disease in South Africa.

BACKGROUND: Mendelian Susceptibility to Mycobacterial Disease (MSMD) is a primary immunodeficiency (PID) characterised by a predisposition to infection by weakly-pathogenic mycobacteria. In countries with a high prevalence of tuberculosis (TB), individuals with MSMD are also prone to infections by Mycobacterium tuberculosis. Several MSMD-associated genes have been described, all resulting in a disruption of IL-12 and IFN-γ cytokine axis, which is essential for control of mycobacterial infections. An accurate molecular diagnosis, confirmed by phenotypic and functional immune investigations, is essential to ensure that the patient receives optimal treatment and prophylaxis for infections. The aim of this study was to implement a set of functional assays to assess the integrity of the IL-12-IFN-γ cytokine pathways in patients presenting with severe, persistent, unusual and/or recurrent TB, mycobacterial infections or other clinical MSMD-defining infections such as Salmonella. METHODS: Blood was collected for subsequent PBMC isolation from 16 participants with MSMD-like clinical phenotypes. A set of flow cytometry (phenotype and signalling integrity) and ELISA-based (cytokine production) functional assays were implemented to assess the integrity of the IL-12-IFN-γ pathway. RESULTS: The combination of the three assays for the assessment of the integrity of the IL-12-IFN-γ pathway was successful in identifying immune deficits in the IL-12-IFN-γ pathway in all of the participants included in this study. CONCLUSIONS: The data presented here emphasise the importance of investigating PID and TB susceptibility in TB endemic regions such as South Africa as MSMD and other previously described PIDs relating to TB susceptibility may present differently in such regions. It is therefore important to have access to in vitro functional investigations to better understand the immune function of these individuals. Although functional assays alone are unlikely to always provide a clear diagnosis, they do give an overview of the integrity of the IL-12-IFN-γ pathway. It would be beneficial to apply these assays routinely to patients with suspected PID relating to mycobacterial susceptibility. A molecular diagnosis with confirmed functional impairment paves the way for targeted treatment and improved disease management options for these patients.

Clinical Utility of Whole Exome Sequencing and Targeted Panels for the Identification of Inborn Errors of Immunity in a Resource-Constrained Setting.

Primary immunodeficiency disorders (PIDs) are inborn errors of immunity (IEI) that cause immune system impairment. To date, more than 400 single-gene IEI have been well defined. The advent of next generation sequencing (NGS) technologies has improved clinical diagnosis and allowed for discovery of novel genes and variants associated with IEI. Molecular diagnosis provides clear clinical benefits for patients by altering management, enabling access to certain treatments and facilitates genetic counselling. Here we report on an 8-year experience using two different NGS technologies, namely research-based WES and targeted gene panels, in patients with suspected IEI in the South African healthcare system. A total of 52 patients' had WES only, 26 had a targeted gene panel only, and 2 had both panel and WES. Overall, a molecular diagnosis was achieved in 30% (24/80) of patients. Clinical management was significantly altered in 67% of patients following molecular results. All 24 families with a molecular diagnosis received more accurate genetic counselling and family cascade testing. Results highlight the clinical value of expanded genetic testing in IEI and its relevance to understanding the genetic and clinical spectrum of the IEI-related disorders in Africa. Detection rates under 40% illustrate the complexity and heterogeneity of these disorders, especially in an African population, thus highlighting the need for expanded genomic testing and research to further elucidate this.

Biogeography of the Relationship between the Child Gut Microbiome and Innate Immune System.

The gut microbiome is a well-recognized modulator of host immunity, and its compositions differ between geographically separated human populations. Systemic innate immune responses to microbial derivatives also differ between geographically distinct human populations. However, the potential role of the microbiome in mediating geographically varied immune responses is unexplored. We here applied 16S amplicon sequencing to profile the stool microbiome and, in parallel, measured whole-blood innate immune cytokine responses to several pattern recognition receptor (PRR) agonists among 2-year-old children across biogeographically diverse settings. Microbiomes differed mainly between high- and low-resource environments and were not strongly associated with other demographic factors. We found strong correlations between responses to Toll-like receptor 2 (TLR2) and relative abundances of Bacteroides and Prevotella populations, shared among Canadian and Ecuadorean children. Additional correlations between responses to TLR2 and bacterial populations were specific to individual geographic cohorts. As a proof of concept, we gavaged germfree mice with human donor stools and found murine splenocyte responses to TLR stimulation were consistent with responses of the corresponding human donor populations. This study identified differences in immune responses correlating to gut microbiomes across biogeographically diverse settings and evaluated biological plausibility using a mouse model. This insight paves the way to guide optimization of population-specific interventions aimed to improve child health outcomes.IMPORTANCE Both the gut microbiome and innate immunity are known to differ across biogeographically diverse human populations. The gut microbiome has been shown to directly influence systemic immunity in animal models. With this, modulation of the gut microbiome represents an attractive avenue to improve child health outcomes associated with altered immunity using population-specific approaches. However, there are very scarce data available to determine which members of the gut microbiome are associated with specific immune responses and how these differ around the world, creating a substantial barrier to rationally designing such interventions. This study addressed this knowledge gap by identifying relationships between distinct bacterial taxa and cytokine responses to specific microbial agonists across highly diverse settings. Furthermore, we provide evidence that immunomodulatory effects of region-specific stool microbiomes can be partially recapitulated in germfree mice. This is an important contribution toward improving global child health by targeting the gut microbiome.

Human whole genome sequencing in South Africa.

The advent and evolution of next generation sequencing has considerably impacted genomic research. Until recently, South African researchers were unable to access affordable platforms capable of human whole genome sequencing locally and DNA samples had to be exported. Here we report the whole genome sequences of the first six human DNA samples sequenced and analysed at the South African Medical Research Council's Genomics Centre. We demonstrate that the data obtained is of high quality, with an average sequencing depth of 36.41, and that the output is comparable to data generated internationally on a similar platform. The Genomics Centre creates an environment where African researchers are able to access world class facilities, increasing local capacity to sequence whole genomes as well as store and analyse the data.

Innate Immune Responses and Gut Microbiomes Distinguish HIV-Exposed from HIV-Unexposed Children in a Population-Specific Manner.

In both high- and low-income countries, HIV-negative children born to HIV-positive mothers (HIV exposed, uninfected [HEU]) are more susceptible to severe infection than HIV-unexposed, uninfected (HUU) children, with altered innate immunity hypothesized to be a cause. Both the gut microbiome and systemic innate immunity differ across biogeographically distinct settings, and the two are known to influence each other. And although the gut microbiome is influenced by HIV infection and may contribute to altered immunity, the biogeography of immune-microbiome correlations among HEU children have not been investigated. To address this, we compared the innate response and the stool microbiome of 2-y-old HEU and HUU children from Belgium, Canada, and South Africa to test the hypothesis that region-specific immune alterations directly correlate to differences in their stool microbiomes. We did not detect a universal immune or microbiome signature underlying differences between HEU versus HUU that was applicable to all children. But as hypothesized, population-specific differences in stool microbiomes were readily detected and included reduced abundances of short-chain fatty acid-producing bacteria in Canadian HEU children. Furthermore, we did not identify innate immune-microbiome associations that distinguished HEU from HUU children in any population. These findings suggest that maternal HIV infection is independently associated with differences in both innate immunity and the stool microbiome in a biogeographical population-specific way.

Identification of a novel WAS mutation in a South African patient presenting with atypical Wiskott-Aldrich syndrome: a case report.

BACKGROUND: The X-linked recessive primary immunodeficiency disease (PIDD) Wiskott-Aldrich syndrome (WAS) is identified by an extreme susceptibility to infections, eczema and thrombocytopenia with microplatelets. The syndrome, the result of mutations in the WAS gene which encodes the Wiskott-Aldrich protein (WASp), has wide clinical phenotype variation, ranging from classical WAS to X-linked thrombocytopaenia and X-linked neutropaenia. In many cases, the diagnosis of WAS in first affected males is delayed, because patients may not present with the classic signs and symptoms, which may intersect with other thrombocytopenia causes. CASE PRESENTATION: Here, we describe a three-year-old HIV negative boy presenting with recurrent infections, skin rashes, features of autoimmunity and atopy. However, platelets were initially reported as normal in numbers and morphology as were baseline immune investigations. An older male sibling had died in infancy from suspected immunodeficiency. Uncertainty of diagnosis and suspected severe PIDD prompted urgent further molecular investigation. Whole exome sequencing identified c. 397 G > A as a novel hemizygous missense mutation located in exon 4 of WAS. CONCLUSION: With definitive molecular diagnosis, we could target treatment and offer genetic counselling and prenatal diagnostic testing to the family. The identification of novel variants is important to confirm phenotype variations of a syndrome.

Primary immunodeficiency diseases in a tuberculosis endemic region: challenges and opportunities.

While individual primary immunodeficiency diseases (PIDs) are rare, collectively they represent a significant burden of disease. Recent estimates show that about one million people in Africa suffer from a PID. However, data from African PID registries reflect only a small percentage of the estimated prevalence. This disparity is partly due to the lack of PID awareness and the masking of PIDs by the endemic pathogens. Over three million tuberculosis (TB) cases were reported in Africa in 2016, with many of these from southern Africa. Despite concerted efforts to address this high burden of disease, the underlying genetic correlates of susceptibility to TB remain poorly understood. High penetrance mutations in immune system genes can cause PIDs that selectively predispose individuals to TB and other mycobacterial diseases. Additionally, the identification of individuals at a heightened risk of developing TB or of presenting with severe or disseminated TB due to their genetic ancestry is crucial to promote a positive treatment outcome. The screening for and identification of PID mutations in TB-endemic regions by next-generation sequencing (NGS) represents a promising approach to improve the understanding of what constitutes an effective immune response to TB, as well as the range of associated PIDs and phenotypes.

Early Breastfeeding Cessation Among HIV-Infected and HIV-Uninfected Women in Western Cape Province, South Africa.

As part of the Mother-Infant Health Study, we describe infant feeding practices among HIV-infected and HIV-uninfected mothers over a 12-month period when the Western Cape Province prevention of mother-to-child transmission (PMTCT) program was transitioning from a policy of exclusive formula feeding to one of exclusive breastfeeding. Two hundred pairs of mother and HIV-uninfected infant were included in the analysis, among whom 81 women were HIV uninfected and breastfeeding. Of the 119 HIV-infected mothers, 50 (42%) were breastfeeding and 69 (58%) were formula feeding. HIV-infected mothers predominantly breastfed for 8.14 (7.71-15.86) weeks; HIV-uninfected mothers predominantly breastfed for 8.29 (8.0-16.0) weeks; and HIV-infected mothers predominantly formula fed for 50.29 (36.43-51.43) weeks. A woman's HIV status had no influence on the time to stopping predominant breastfeeding (P = 0.20). Our findings suggest suboptimal duration of breastfeeding among both HIV-infected and HIV-uninfected mothers. Providing support for all mothers postdelivery, regardless of their HIV status, may improve breastfeeding practices.

Exome Sequencing Identifies a Novel MAP3K14 Mutation in Recessive Atypical Combined Immunodeficiency.

Primary immunodeficiency disorders (PIDs) render patients vulnerable to infection with a wide range of microorganisms and thus provide good in vivo models for the assessment of immune responses during infectious challenges. Priming of the immune system, especially in infancy, depends on different environmental exposures and medical practices. This may determine the timing and phenotype of clinical appearance of immune deficits as exemplified with early exposure to Bacillus Calmette-Guérin (BCG) vaccination and dissemination in combined immunodeficiencies. Varied phenotype expression poses a challenge to identification of the putative immune deficit. Without the availability of genomic diagnosis and data analysis resources and with limited capacity for functional definition of immune pathways, it is difficult to establish a definitive diagnosis and to decide on appropriate treatment. This study describes the use of exome sequencing to identify a homozygous recessive variant in MAP3K14, NIKVal345Met, in a patient with combined immunodeficiency, disseminated BCG-osis, and paradoxically elevated lymphocytes. Laboratory testing confirmed hypogammaglobulinemia with normal CD19, but failed to confirm a definitive diagnosis for targeted treatment decisions. NIKVal345Met is predicted to be deleterious and pathogenic by two in silico prediction tools and is situated in a gene crucial for effective functioning of the non-canonical nuclear factor-kappa B signaling pathway. Functional analysis of NIKVal345Met- versus NIKWT-transfected human embryonic kidney-293T cells showed that this mutation significantly affects the kinase activity of NIK leading to decreased levels of phosphorylated IkappaB kinase-alpha (IKKα), the target of NIK. BCG-stimulated RAW264.7 cells transfected with NIKVal345Met also presented with reduced levels of phosphorylated IKKα, significantly increased p100 levels and significantly decreased p52 levels compared to cells transfected with NIKWT. Ideally, these experiments would have been conducted in patient-derived immune cells, but we were unable to source these cells from the patient. The functional analysis described in this paper supports previous illustrations of the importance of NIK in human immune responses and demonstrates the involvement of function-altering mutations in MAP3K14 in PIDs. The genomic approach used for this patient demonstrates its value in the diagnosis of an unusual PID and as a tool for detecting rarer mutations to help guide treatment approaches.

Exome sequencing identifies a novel TTC37 mutation in the first reported case of Trichohepatoenteric syndrome (THE-S) in South Africa.

BACKGROUND: Trichohepatoenteric syndrome (THE-S) or phenotypic diarrhoea of infancy is a rare autosomal recessive disorder characterised by severe infantile diarrhoea, facial dysmorphism, immunodeficiency and woolly hair. It was first described in 1982 in two infants with intractable diarrhoea, liver cirrhosis and abnormal hair structure on microscopy. We report on two siblings from a consanguineous family of Somali descent who, despite extensive clinical investigation, remained undiagnosed until their demise. The index patient died of fulminant cytomegalovirus pneumonitis at 3 months of age. METHODS: Whole exome sequencing (WES) was performed on a premortem DNA sample from the index case. Variants in a homozygous recessive state or compound heterozygous state were prioritized as potential candidate variants using TAPER™. Sanger sequencing was done to genotype the parents, unaffected sibling and a deceased sibling for the variant of interest. RESULTS: Exome sequencing identified a novel homozygous mutation (c.4507C > T, rs200067423) in TTC37 which was confirmed by Sanger sequencing in the index case. The identification of this mutation led to the diagnosis of THE-S in the proband and the same homozygous variant was confirmed in a male sibling who died 4 years earlier with severe chronic diarrhoea of infancy. The unaffected parents and sister were heterozygous for the identified variant. CONCLUSIONS: WES permitted definitive genetic diagnosis despite an atypical presentation in the index case and suggests that severe infection, likely secondary to immunodeficiency, may be a presenting feature. In addition definitive molecular diagnosis allows for genetic counseling and future prenatal diagnosis, and demonstrates the value of WES for post-mortem diagnosis of disorders with a non-specific clinical presentation in which a Mendelian cause is suspected.

Placental pathology in HIV infection at term: a comparison with HIV-uninfected women.

OBJECTIVES: To describe and correlate placental characteristics from pregnancies in HIV-infected and HIV-negative women with maternal and infant clinical and immunological data. METHODS: Prospective descriptive study of placentas from term, uncomplicated vaginal births in a cohort of HIV-infected (n = 120) and HIV-negative (n = 103) women in Cape Town, South Africa. Microscopic and macroscopic features were used to determine pathological cluster diagnoses. The majority of HIV-infected women received some form of drug treatment for the prevention of vertical transmission of HIV. Data were analysed using logistic regression. RESULTS: HIV-infected women were older (median [IQR] 27.4 years [24-31] vs. 25.8 [23-30]), more likely to be multiparous (81.7% vs. 71.8%) and had lower CD4 counts (median [IQR] 323.5 cells/ml [235-442] vs. 467 [370-656]). There were no differences in gestational age at first antenatal visit or at delivery. The proportion of specimens with placental lesions was similar in both groups (39.2% vs. 44.7%). Half of all samples were below the tenth percentile expected-weight-for-gestation regardless of HIV status. This was unaffected by adjustment for confounding variables. Maternal vascular malperfusion (MVM) was more frequent in HIV infection (24.2% vs. 12.6%; P = 0.028), an association which strengthened after adjustment (aOR 2.90 [95% confidence interval 1.11-7.57]). Otherwise the frequency of individual diagnoses did not differ between the groups on multivariate analysis. CONCLUSIONS: In this cohort of term, uncomplicated pregnant women, few differences were observed between the HIV-infected and uninfected groups apart from MVM. This lesion may underlie the development of hypertensive disorders of pregnancy, which have been observed at higher rates in some HIV-infected women on ART.

A Prospective Cohort Study of Common Childhood Infections in South African HIV-exposed Uninfected and HIV-unexposed Infants.

BACKGROUND: Much evidence of HIV-exposed uninfected (HEU) infant infectious morbidity predates availability of maternal combination antiretroviral therapy and does not control for universal risk factors (preterm birth, low birth weight, suboptimal breastfeeding and poverty). METHODS: This prospective cohort study identified HIV-infected and HIV-uninfected mothers and their newborns from South African community midwife unit. The primary outcome, infectious cause hospitalization or death before 6 months of age, was compared between HEU and HIV-unexposed (HU) infants and classified for type and severity using validated study-specific case definitions. Adjusted odds ratios (aORs) were calculated by logistic regression including stratified analyses conditioned on breastfeeding. RESULTS: One hundred and seventy-six (94 HEU and 82 HU) mother-infant pairs were analyzed. HIV-infected mothers were older (median, 27.8 vs. 24.7 years; P < 0.01) and HU infants more often breastfed (81/82 vs. 35/94; P < 0.001). Groups were similar for maternal education, antenatal course, household characteristics, birth weight, gestational age and immunizations. The primary outcome occurred in 17 (18%) HEU and 10 (12%) HU infants [aOR, 1.45; 95% confidence interval (CI): 0.44-4.55]. In stratified analysis restricted to breastfed infants, the aOR for hospitalization due to very severe infection or death was 4.2 (95% CI: 1.00-19.2; P = 0.05) for HEU infants. Hospitalization for diarrhea was more common in HEU than HU infants [8/94 (8.5%) vs. 1/82 (1.2%); P = 0.04]. CONCLUSION: The difference between HEU and HU infants in the probability of infectious cause hospitalization or death in the first 6 months of life was not significant. However, among breastfed infants, severe infectious morbidity occurred more often in HEU than HU infants.

The neuromyelitis optica presentation and the aquaporin-4 antibody in HIV-seropositive and seronegative patients in KwaZulu-Natal, South Africa.

BACKGROUND: The association of the anti-aquaporin-4 (AQP-4) water channel antibody with neuromyelitis optica (NMO) syndrome has been described from various parts of the world. There has been no large study describing this association from southern Africa, an HIV endemic area. HIV patients often present with visual disturbance or features of a myelopathy but seldom both either simultaneously or consecutively. We report our experience of NMO in the era of AQP-4 testing in HIV-positive and HIV-negative patients seen in KwaZulu-Natal, South Africa. METHODS: A retrospective chart review was undertaken of NMO cases seen from January 2005 to April 2016 in two neurology units serving a population of 7.1 million adults. The clinical, radiological and relevant laboratory data were extracted from the files and analysed. RESULTS: There were 12 HIV-positive patients (mean age 33 years), 9 (75%) were women and all 12 were black patients. Of the 17 HIV-negative patients (mean age 32 years), 15 (88%) were women and 10 (59%) were black people. The clinical features in the two groups ranged from isolated optic neuritis, isolated longitudinally extensive myelitis or combinations. Recurrent attacks were noted in six HIV-positive patients and six HIV-negative patients. The AQP-4 antibody was positive in 4/10 (40%) HIV-positive patients and 11/13 (85%) HIV-negative patients. The radiological changes ranged from longitudinal hyperintense spinal cord lesions and long segment enhancing lesions of the optic nerves. Three patients, all HIV-positive, had tumefactive lesions with incomplete ring enhancement. CONCLUSION: This study confirms the presence of AQP-4-positive NMO in southern Africa in both HIV-positive and HIV-negative patients. The simultaneous or consecutive occurrence of optic neuritis and myelitis in an HIV-positive patient should alert the clinician to test for the AQP-4 antibody. It is important to recognise this clinical syndrome as specific therapy is available. We further postulate that HIV itself may act as a trigger for an autoimmune process.

Characteristics and outcome of children with juvenile dermatomyositis in Cape Town: a cross-sectional study.

BACKGROUND: Juvenile dermatomyositis (JDM) is a rare idiopathic inflammatory childhood myopathy of uncertain aetiology. The demographic and clinical presentation of JDM may differ by race and geographic regions. Few studies have described the characteristics of JDM patients from Africa. METHODS: We conducted a retrospective observational study to determine clinical characteristics and outcomes of patients satisfying the Bohan and Peter criteria for probable JDM seen between 2004 and 2013 in three hospitals in Cape Town, South Africa. RESULTS: Twenty five cases were identified: 16 female and 9 male; thirteen (52 %) were of indigenous African, eleven (44 %) mixed and one (4 %) European ancestry. The median ages at disease onset and diagnosis were 6.75 (range 2.0-9.7) and 7.9 (range 3.4-9.75) years respectively. Eleven patients had calcinosis while the mortality was 2/25 (8 %). Only 40 % of the patients had clinically inactive disease by PRINTO criteria (modified) at last review. There was no statistically significant difference in racial distribution (p-value = 1), age at disease onset (p-value = 0.87) and disease duration prior to treatment initiation (p-value = 0.75) between patients who had clinically active and inactive disease. CONCLUSION: The demographic characteristics of children with JDM were similar to that from most other regions of the world with female predominance and similar age at onset. Majority of the patients remained with clinically active disease, which put them at risk of further disease complications. Long term follow up and use of appropriate treatment guidelines may be indicated in management of JDM patients for optimum treatment outcomes.

Keeping kids in care: virological failure in a paediatric antiretroviral clinic and suggestions for improving treatment outcomes.

The burden of paediatric HIV in South Africa is extremely high. Antiretrovirals (ARVs) are now widely accessible in the country and the clinical emphasis has shifted from initiation of treatment to retention in care. This study describes the cumulative virological failure rate amongst children on ARVs in a peri-urban clinic, and suggests ways in which clinics and partners could improve treatment outcomes. The study was conducted by the non-profit organisation HOPE Cape Town Association. A retrospective file audit determined the cumulative virological failure rate, that is, the sum of all children with a viral load >1000 copies/ml, children on monotherapy, children who had stopped treatment, children lost to follow-up (LTFU) and children who had died. Interviews were conducted with a purposive sample of 12 staff members and a random sample of 21 caregivers and 4 children attending care. Cumulative virological failure rate was 42%, with most of those children having been LTFU. Both staff and caregivers consistently identified pharmacy queues, ongoing stigma and unpalatable ARVs as barriers to adherence. Staff suggestions included use of adherence aids, and better education and support groups for caregivers. Caregivers also requested support groups, as well as "same day" appointments for caregivers and children, but rejected the idea of home visits. Simple, acceptable and cost-effective strategies exist whereby clinics and their partners could significantly reduce the cumulative virological failure rate in paediatric ARV clinics. These include actively tracing defaulters, improving education, providing support groups, and campaigning for palatable ARV formulations.

Delayed BCG immunization does not alter antibody responses to EPI vaccines in HIV-exposed and -unexposed South African infants.

BACKGROUND: Bacille Calmette-Guérin (BCG) is routinely given at birth in tuberculosis-endemic settings due to its protective effect against disseminated tuberculosis in infants. BCG is however contraindicated in HIV-infected infants. We investigated whether delaying BCG vaccination to 14 weeks of age affected vaccine-induced antibody responses to Haemophilus influenzae type b (Hib)-conjugate, pertussis, tetanus and Hepatitis B (HBV) vaccines, in HIV-exposed uninfected (HEU) and -unexposed uninfected (HUU) infants. METHODS: Infants were randomized to receive BCG at birth or at 14 weeks of age. Blood was taken at 14, 24, and 52 weeks of age and analyzed for Hib, pertussis, tetanus and HBV specific antibodies. RESULTS: BCG was given either at birth (106 infants, 51 HEU) or at 14 weeks of age (74 infants, 50 HEU). The timing of BCG vaccination did not influence the antibody response to any antigen studied. However, in a non-randomized comparison, HEU infants had higher Hib antibody concentrations at weeks 14 and 24 (p=0.001 and <0.001, respectively) and pertussis at week 24 (p=0.003). Conversely, HEU infants had lower antibody concentrations to HBV at 14 and 52 weeks (p=0.032 and p=0.031) with no differences in tetanus titres. CONCLUSIONS: HIV exposure, but not the timing of BCG vaccination, was associated with antibody concentrations to Hib, pertussis, HBV and tetanus primary immunization. CLINICAL TRIAL REGISTRATION: DOH-27-1106-1520.

Feeding practices and nutritional status of HIV-exposed and HIV-unexposed infants in the Western Cape.

BACKGROUND: Optimal infant- and young child-feeding practices are crucial for nutritional status, growth, development, health and, ultimately, survival. Human breast milk is optimal nutrition for all infants. Complementary food introduced at the correct age is part of optimal feeding practices. In South Africa, widespread access to antiretrovirals and a programme to prevent mother-to-child transmission of HIV have reduced HIV infection in infants and increased the number of HIV-exposed uninfected (HEU) infants. However, little is known about the feeding practices and nutritional status of HEU and HIV-unexposed (HU) infants. OBJECTIVE: To assess the feeding practices and nutritional status of HIV-exposed and HIV-unexposed (HU) infants in the Western Cape. DESIGN: Prospective substudy on feeding practices nested in a pilot study investigating the innate immune abnormalities in HEU infants compared to HU infants. The main study commenced at week 2 of life with the nutrition component added from 6 months. Information on children's dietary intake was obtained at each visit from the caregiver, mainly the mother. Head circumference, weight and length were recorded at each visit. Data were obtained from 6-, 12- and 18-month visits. World Health Organization feeding practice indicators and nutrition indicators were utilised. SETTING: Tygerberg Academic Hospital, Western Cape. Mothers were recruited from the postnatal wards. SUBJECTS: Forty-seven mother-infant pairs, 25 HEU and 22 HU infants, participated in this nutritional substudy. Eight (17%) infants, one HU and seven HEU, were lost to follow-up over the next 12 months. The HEU children were mainly Xhosa (76%) and HU were mainly mixed race (77%). RESULTS: The participants were from poor socio-economic backgrounds. In both groups, adherence to breastfeeding recommendations was low with suboptimal dietary diversity. We noted a high rate of sugar- and salt-containing snacks given from a young age. The HU group had poorer anthropometric and nutritional indicators not explained by nutritional factors alone. However, alcohol and tobacco use was much higher amongst the HU mothers. CONCLUSION: Adherence to breastfeeding recommendations was low. Ethnicity and cultural milieu may have influenced feeding choices and growth. Further research is needed to understand possible reasons for the poorer nutritional and anthropometric indicators in the HU group.