Zinc and multivitamin supplementation have contrasting effects on infant iron status: a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND/OBJECTIVES: Zinc (Zn) supplementation adversely affects iron status in animal and adult human studies, but few trials have included young infants. The objective of this study was to determine the effects of Zn and multivitamin (MV) supplementation on infant hematologic and iron status. SUBJECTS/METHODS: In a double-blind RCT, Tanzanian infants were randomized to daily, oral Zn, MV, Zn and MV or placebo treatment arms at the age of 6 weeks of life. Hemoglobin concentration (Hb) and red blood cell indices were measured at baseline and at 6, 12 and 18 months of age. Plasma samples from 589 infants were examined for iron deficiency (ID) at 6 months. RESULTS: In logistic regression models, Zn treatment was associated with greater odds of ID (odds ratio (OR) 1.8 (95% confidence interval (CI) 1.0-3.3)) and MV treatment was associated with lower odds (OR 0.49 (95% CI 0.3-0.9)). In Cox models, MV was associated with a 28% reduction in risk of severe anemia (hazard ratio (HR)=0.72 (95% CI 0.56-0.94)) and a 26% reduction in the risk of severe microcytic anemia (HR=0.74 (0.56-0.96)) through 18 months. No effects of Zn on risk of anemia were seen. Infants treated with MV alone had higher mean Hb (9.9 g/dl (95% CI 9.7-10.1)) than those given placebo (9.6 g/dl (9.4-9.8)) or Zn alone (9.6 g/dl (9.4-9.7)). CONCLUSIONS: MV treatment improved iron status in infancy, whereas Zn worsened iron status but without an associated increase in risk for anemia. Infants in long-term Zn supplementation programs at risk for ID may benefit from screening and/or the addition of a MV supplement.

Detecting virological failure in HIV-infected Tanzanian children.

BACKGROUND: The performance of clinical and immunological criteria to predict virological failure in HIV-infected children receiving antiretroviral therapy (ART) is not well documented. OBJECTIVE: To determine the validity of clinical and immunological monitoring in detecting virological failure in children on ART. METHODS: A total of 218 children were included in the study. All were from care and treatment clinics in Dar es Salaam, Tanzania. Their mean age was 10.6 years, 122 (56.0%) were males, and the mean time on ART was 40.9 months. The study was conducted from August 2011 to March 2012. Data on sociodemographic and clinical characteristics and immunological and virological failure were based on World Health Organization definitions. Blood samples were collected for CD4+ T-cell count and viral load tests. RESULTS: Of 217 children with available viral load results, 124 (57.1%) had virological failure (>400 copies/mL), 25.0% immunological failure and 11.5% clinical failure. The sensitivity, specificity, positive predictive value and negative predictive value of clinical criteria were 12.9%, 90.3%, 64.0% and 43.8%, respectively, those for immunological criteria 22.6%, 73.1%, 53.3% and 41.4%, and those for the combination of clinical and immunological monitoring 25.8%, 69.9%, 53.3% and 41.4%. Children who received nevirapine (NVP)-based regimens were two times more likely (odds ratio 2.0; 95% confidence interval 1.20 - 3.64) to have virological failure than those on efavirenz and protease inhibitor-based regimens. CONCLUSIONS: The study demonstrated poor performance of currently recommended clinical and immunological criteria for monitoring HIV-infected children on ART. Moreover, children on NVP-based regimens had a higher risk of developing virological failure than those on other regimens.

Clinical malaria diagnosis in pregnancy in relation to early perinatal mother-to-child transmission of HIV: a prospective cohort study.

OBJECTIVES: We prospectively investigated fever symptoms and maternal diagnosis of malaria in pregnancy (MIP) in relation to child HIV infection among 2368 pregnant HIV-positive women and their infants, followed up from pregnancy until 6 weeks post-delivery in Tanzania. METHODS: Doctors clinically diagnosed and treated MIP and fever symptoms during prenatal health care. Child HIV status was determined via DNA polymerase chain reaction (PCR). Multivariable logistic regression models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for HIV mother-to-child transmission (MTCT) by the 6th week of life. RESULTS: Mean gestational age at enrolment was 22.2 weeks. During follow-up, 16.6% of mothers had at least one MIP diagnosis, 15.9% reported fever symptoms and 8.7% had both fever and MIP diagnosis. Eleven per cent of HIV-exposed infants were HIV-positive by 6 weeks. The RR of HIV MTCT was statistically similar for infants whose mothers were ever vs. never clinically diagnosed with MIP (RR 1.24; 95% CI 0.94-1.64), were diagnosed with one vs. no clinical MIP episodes (RR 1.07; 95% CI 0.77-1.48) and had ever vs. never reported fever symptoms (RR 1.04; 95% CI 0.78-1.38) in pregnancy. However, the HIV MTCT risk increased by 29% (95% CI 4-58%) per MIP episode. Infants of women with at least two vs. no MIP diagnoses were 2.1 times more likely to be HIV infected by 6 weeks old (95% CI 1.31-3.45). CONCLUSIONS: Clinical MIP diagnosis, but not fevers, in HIV-positive pregnant women was associated with an elevated risk of early HIV MTCT, suggesting that malaria prevention and treatment in pregnant HIV-positive women may enhance the effectiveness of HIV prevention in MTCT programmes in this setting. Future studies using a laboratory-confirmed diagnosis of malaria are needed to confirm this association.

Predictors of stunting, wasting and underweight among Tanzanian children born to HIV-infected women.

BACKGROUND/OBJECTIVES: Children born to human immunodeficiency virus (HIV)-infected women are susceptible to undernutrition, but modifiable risk factors and the time course of the development of undernutrition have not been well characterized. The objective of this study was to identify maternal, socioeconomic and child characteristics that are associated with stunting, wasting and underweight among Tanzanian children born to HIV-infected mothers, followed from 6 weeks of age for 24 months. SUBJECTS/METHODS: Maternal and socioeconomic characteristics were recorded during pregnancy, data pertaining to the infant's birth were collected immediately after delivery, morbidity histories and anthropometric measurements were performed monthly. Multivariate Cox proportional hazards methods were used to assess the association between potential predictors and the time to first episode of stunting, wasting and underweight. RESULTS: A total of 2387 infants (54.0% male) were enrolled and followed for a median duration of 21.2 months. The respective prevalence of prematurity (<37 weeks) and low birth weight (<2500 g) was 15.2% and 7.0%; 11.3% of infants were HIV-positive at 6 weeks. Median time to first episode of stunting, wasting and underweight was 8.7, 7.2 and 7.0 months, respectively. Low maternal education, few household possessions, low infant birth weight, child HIV infection and male sex were all independent predictors of stunting, wasting and underweight. In addition, preterm infants were more likely to become wasted and underweight, whereas those with a low Apgar score at birth were more likely to become stunted. CONCLUSIONS: Interventions to improve maternal education and nutritional status, reduce mother-to-child transmission of HIV, and increase birth weight may lower the risk of undernutrition among children born to HIV-infected women.

Neonatal hypothermia on admission to a special care unit in Dar-es-Salaam, Tanzania: a cause for concern.

OBJECTIVE: To determine the prevalence and risk factors for hypothermia among neonates on admission to the Neonatal Care Unit. Hypothermia in newborn babies is a problem in tropical countries despite warm environmental conditions and it contributes to a high neonatal morbidity and mortality. METHODOLOGY: A study was undertaken to determine the prevalence of hypothermia and its association with early neonatal outcome among neonates admitted to the Neonatal Care Unit of Muhimbili Medical Centre. At admission all neonates were examined and axillary temperature recorded using a low-reading thermometer. Six-hourly temperature was taken in all infants. Those with a temperature below 36.5 degrees C were recruited as cases and those with normal temperature served as controls. These neonates were followed up for early neonatal outcome. RESULTS: Hypothermia on admission was found in 366 out of 1,632 babies (22.4%). In none of these was hypothermia recorded or reported as a reason for admission. Thirteen percent of the hypothermic neonates had severe hypothermia, with body temperature below 32 degrees C on admission. Hypothermia was significantly associated with deliveries from outside hospitals and with those who had operative or instrumental delivery in the same hospital. It was also associated with prematurity, low birth weight babies, time taken to transfer the baby and inadequate clothing after delivery. It was found that hypothermic infants had a three fold higher mortality and morbidity. These infants had a longer stay in the unit and had a higher post natal weight loss. There was no low-reading thermometer in the unit. CONCLUSION: It is concluded that there is cause for concern about hypothermia in the neonates at Muhimbili Medical Centre. Efforts should be made to sensitize and educate all levels of staff dealing with neonates, and low-reading thermometers should be part of the essential kit in the unit.

The reconstitution of CD45RBhiCD4+ naive T cells is inversely correlated with donor age in murine allogeneic haematopoietic stem cell transplantation.

A high incidence of opportunistic infections after unrelated bone marrow transplantation has been reported. Delayed lymphocyte recovery may be associated with opportunistic infections. Immune reconstitution is influenced by recipient age and graft-vs-host disease (GVHD). In fact, children develop GVHD less frequently than adults. However, the role of donor age is largely unknown. We examined the effect of donor age on lymphocyte reconstitution after transplant. Three-month-old BALB/c recipient mice were lethally irradiated and transplanted with allogeneic haematopoietic stem cells from A/J donor mice of different ages, ranging from 0 d to 12 months. The recovery of absolute lymphocyte counts and those of CD3+ T cells, CD4+ T cells and CD45RBhi CD4+ naive T cells in the early post-transplant period correlated inversely with donor age. Recipient mice transplanted with haematopoietic stem cells from younger donors showed significantly higher survival rates and mitogenic responses than adult donors. As T cells, especially CD4+ naive T cells, play an important role in host defence, faster recovery of CD4+ naive T cells in younger donors may contribute to reduced mortality in the early post-transplant period. The results suggest that it could be better to choose a younger donor if sufficient cell dose is available.

Activation-induced T cell death occurs at G1A phase of the cell cycle.

Peripheral negative selection of cycling T cells after TCR engagement and deletion of activated T cells after an immune response occur by an apoptotic process termed activation-induced cell death (AICD). The cross-linking of TCR-CD3 complex with anti-CD3 monoclonal antibody led to significant apoptotic cell death in peripheral blood T cells. To further define cell cycle restriction points for triggering AICD in T cells, we evaluated the association between cell cycle progression and death signal transduction. Simultaneous DNA / RNA quantification analysis revealed that T cells entering G1A phase of the cell cycle may acquire sensitivity to AICD. The activation of caspase-3 was induced when T cells entered G1A phase. Up-regulation of cyclin-dependent kinases (Cdk4 and Cdk6) and cyclin D3 was initiated in TCR-stimulated T cells entering G1A phase and expression of these markers steadily increased as T cells progressed from G1A into G1B phase. Interestingly, caspase-3 inhibitors could inhibit the up-regulation of these G1 cell cycle regulators and induce G0 / G1A arrest as well as the inhibition of AICD. On the basis of these results, AICD signals are most likely transduced into TCR-stimulated T cells entering G1A phase. T cells that fail to progress from G1A into G1B phase undergo AICD.