Lymphocyte phenotyping to distinguish septic from nonseptic critical illness

BACKGROUND: Clinical signs and symptoms of sepsis are nonspecific and often indistinguishable from those of nonseptic critical illness. This ambiguity frequently delays the diagnosis of sepsis until culture results can confirm the presence or absence of an infectious organism. Lymphocyte phenotyping can be conducted rapidly and may provide information on the presence of infection before culture results are available. In this study, we hypothesized that lymphocyte phenotype can distinguish between septic and nonseptic critical illness. STUDY DESIGN: C57Bl/6 mice were subjected to either P aeruginosa pneumonia or lipopolysaccharide-induced acute lung injury (ALI). Animals were sacrificed 24 hours postinjury and splenic lymphocytes were harvested. Additionally, 13 patients in a surgical ICU were enrolled in the study. Whole blood was obtained and lymphocytes were isolated by density gradient centrifugation. Lymphocyte phenotype was identified through flow cytometry after labeling lymphocytes for CD3, CD4, CD8, CD20, CD40, CD69, and CD86 with fluorochrome-conjugated antibodies. RESULTS: CD69 expression on B cells and CD8+ splenocytes from septic mice was significantly increased compared with acute lung injury mice (p < 0.001 and p < 0.05, respectively). Similarly, CD4+ and CD8+ lymphocytes from septic patients had a two- to threefold increase in the expression of CD69 compared with nonseptic critically ill patients (p < 0.05). CONCLUSIONS: These data indicated that CD69 expression on lymphocytes may be useful in distinguishing between septic and nonseptic critical illness. Continued investigation into the expression of CD69 during sepsis is warranted.     

Mortality in HIV-infected and uninfected children of HIV-infected and uninfected mothers in rural Uganda

OBJECTIVE: To estimate 2-year mortality rates in HIV-1-infected and uninfected infants born to HIV and HIV mothers. METHODS: Data are from a prospective study in rural Rakai District, Uganda. Infant HIV status (determined by polymerase chain reaction) was evaluated at 1 to 6 weeks postpartum and during breast-feeding, and maternal HIV viral load and CD4 levels were measured at the postpartum visit. Multivariate Cox proportional hazards models and Kaplan-Meier survival analysis were used to assess survival of infants by maternal and infant HIV status and by quartiles of viral load. Log-rank tests were used to test the equality of survival functions. RESULTS: Of the 4604 pregnant women, 16.9% were HIV, and the proportion of children infected was 20.9%. Median survival of HIV-infected infants was 23 months. Two-year child mortality rates were 128 of 1000 children born to HIV mothers, 165.5 of 1000 uninfected children born to HIV mothers, and 540.1 of 1000 HIV-infected children (P < 0.0001). Compared with children of HIV mothers, the hazard of child mortality was 2.04 (P < 0.001) if the mother was HIV and 3.78 (P < 0.001) if the infant was also infected. In the adjusted model, the highest quartiles of log10 HIV viral load in infants and mothers were associated with significantly increased hazard of child mortality (hazard ratio [HR] = 8.54 and HR = 2.50, respectively). Maternal CD4 counts <200 cells/mL were also significant predictors of child mortality (HR = 2.61). A total of 67.6% of HIV-infected children with viral loads above the median died by the age of 2 years and are in need of early antiretroviral therapy (ART). CONCLUSIONS: More than half of HIV-infected infants died at less than 2 years of age. Therefore, ART may need to be initiated earlier in HIV-infected African children.     

Hemicrania Continua Responsive to Intravenous Methyl Prednisolone

Hemicrania continua (HC) is a strictly unilateral, continuous primary headache disorder with periodic exacerbations, usually accompanied by cranial autonomic disturbances. Exquisite and persistent effect of indomethacin is a fundamental property of HC. We report 2 patients of HC in which attacks were successfully eliminated by repeated infusion of methyl prednisolone.     

Calcineurin Inhibitor Withdrawal After Renal Transplantation with Alemtuzumab: Clinical Outcomes and Effect on T-Regulatory Cells

To address the results of calcineurin inhibitor (CNI) withdrawal after alemtuzumab induction relative to CNI continuation, we performed a pilot randomized clinical trial in renal allograft recipients on CNI, a mycophenolic acid derivative and steroids after the first 2 months posttransplantation. Forty patients were randomized to taper off CNI or to maintain it, and followed for at least 1 year. Four patients in the withdrawal group were treated for acute rejection while no patient received antirejection treatment in the control group. Two control patients withdrew CNI due to nephrotoxicity. Estimated GFR was similar in both groups after 1 year. Flow cytometry of CD4⁺CD25⁺CTLA-4⁺FoxP3⁺ regulatory T cells (Treg) demonstrated a significant increase in Treg percentages in the peripheral blood of alemtuzumab-treated patients on CNI early postransplant. Furthermore, the increased Treg percentages in the withdrawal cohort were unchanged at month 6 postenrollment, whereas they decreased significantly in those patients maintained on CNI. Patients withdrawn from CNI after alemtuzumab trend toward a higher rejection rate, but most patients can be weaned from a CNI using this regimen. With the exception of maintaining increased Treg levels, the benefits are not appreciable in this short follow-up, and a larger randomized trial is justified.     

Child mortality associated with reasons for non-breastfeeding and weaning: is breastfeeding best for HIV-positive mothers?

OBJECTIVE: To estimate child mortality associated with reasons for the non-initiation of breastfeeding and weaning caused by preceding morbidity, compared with voluntary weaning as a result of maternal choice. METHODS: Demographic and Health Surveys were analysed from 14 developing countries. Women reported whether they initiated lactation or weaned, and if so, their reasons for non-initiation or stopping breastfeeding were classified as voluntary choice or as a result of preceding maternal/infant illness. Rates of child mortality and survival analyses were estimated, by reasons for non-breastfeeding or weaning. RESULTS: Mortality was highest among never-breastfed children. Child mortality among women who never initiated breastfeeding was significantly higher than among women who weaned. Preceding maternal/infant morbidity was the most common reason for not breastfeeding (63.9%), and the mortality of children never breastfed because of preceding morbidity was higher than in children not breastfed as a result of maternal choice; 326.8 per 1000 versus 34.8 per 1000, respectively. Mortality among breastfed children who were weaned because of preceding morbidity was higher than among those weaned voluntarily; 19.2 per 1000 versus 9.3 per 1000, respectively. Failure to initiate lactation was significantly more frequent among women reporting complications of delivery and with low birthweight infants. CONCLUSION: Child mortality as a result of the voluntary non-initiation of breastfeeding or voluntary weaning was lower than previously estimated, and this should be used as a benchmark when counselling HIV-positive mothers on the risks of non-breastfeeding or weaning to prevent mother-to-child transmission of HIV.     

Polygyny,maternal HIV status and child survival: Rakai,Uganda

The objective of this research was to assess the association of child mortality with polygyny and maternal HIV status through a prospective community-based study in Rakai district, Uganda. We sought to test whether there was an indirect evidence that polygynous households in an HIV prevalent area may divert resources away from the children of HIV-infected mothers in favor of children with better survival prospects. We test this theory using data from a follow-up study which collected detailed behavioral and medical information at 10-month intervals on a cohort of over 4000 pregnant women and their infants (5300 person years of observation). Cox proportional hazards models estimated the mortality hazard (RR) associated with polygyny for children of HIV-negative and HIV-positive mothers. HIV prevalence in the full cohort of mothers was 11.9%, and 23% of mothers lived in polygynous households. Multivariate analysis showed an increased hazard of child mortality if the mother was HIV-positive (RR = 1.75, p<0.001). Maternal education reduced mortality, whereas low birth weight increased mortality risk. Polygyny was associated with an increase in the hazard of child mortality in the full sample (RR = 1.36, p<0.001) and in mothers who were HIV-positive (RR = 2.17, p<0.001), but not in HIV-negative mothers. Being born to an HIV-positive mother increased mortality risk and polygyny accentuated a child's risk of death. Polygyny had no significant effect on the survival of children with HIV-negative mothers. Polygynous households, where not all wives may have HIV, could be diverting resources away from the children of the infected wives.     

A postgenomic approach to identification of Mycobacterium leprae-specific peptides as T-cell reagents

To identify Mycobacterium leprae-specific human T-cell epitopes, which could be used to distinguish exposure to M. leprae from exposure to Mycobacterium tuberculosis or to environmental mycobacteria or from immune responses following Mycobacterium bovis BCG vaccination, 15-mer synthetic peptides were synthesized based on data from the M. leprae genome, each peptide containing three or more predicted HLA-DR binding motifs. Eighty-one peptides from 33 genes were tested for their ability to induce T-cell responses, using peripheral blood mononuclear cells (PBMC) from tuberculoid leprosy patients (n = 59) and healthy leprosy contacts (n = 53) from Brazil, Ethiopia, Nepal, and Pakistan and 20 United Kingdom blood bank donors. Gamma interferon (IFN-gamma) secretion proved more sensitive for detection of PBMC responses to peptides than did lymphocyte proliferation. Many of the peptides giving the strongest responses in leprosy donors compared to subjects from the United Kingdom, where leprosy is not endemic, have identical, or almost identical, sequences in M. leprae and M. tuberculosis and would not be suitable as diagnostic tools. Most of the peptides recognized by United Kingdom donors showed promiscuous recognition by subjects expressing differing HLA-DR types. The majority of the novel T-cell epitopes identified came from proteins not previously recognized as immune targets, many of which are cytosolic enzymes. Fifteen of the tested peptides had > or =5 of 15 amino acid mismatches between the equivalent M. leprae and M. tuberculosis sequences; of these, eight gave specificities of > or =90% (percentage of United Kingdom donors who were nonresponders for IFN-gamma secretion), with sensitivities (percentage of responders) ranging from 19 to 47% for tuberculoid leprosy patients and 21 to 64% for healthy leprosy contacts. A pool of such peptides, formulated as a skin test reagent, could be used to monitor exposure to leprosy or as an aid to early diagnosis.     

Construction of stable LamB-Shiga toxin B subunit hybrids: analysis of expression in Salmonella typhimurium aroA strains and stimulation of B subunit-specific mucosal and serum antibody responses.

The complete Shiga toxin B subunit and two N-terminal segments of the B subunit have been inserted into a cell surface exposed loop of the LamB protein, and expression of the hybrid proteins from three different promoter systems, i.e., (i) an in vitro-inducible tac promoter that provides high-level expression, (ii) the iron-regulated aerobactin promoter presumably induced in vivo under the iron-limiting conditions of the intestinal mucosal environment, and (iii) a synthetic, modified beta-lactamase promoter providing moderate level constitutive expression, has been analyzed in Escherichia coli, Salmonella typhimurium, and attenuated antigen carrier strains of S. typhimurium (aroA mutants). The hybrid vaccine strains were used to immunize mice by the oral and intraperitoneal routes. S. typhimurium aroA mutants apparently have a membrane export defect which prevents the transport of LamB and its derivatives across the cytoplasmic membrane. High-level expression of hybrid proteins through use of the tac promoter proved deleterious to the vaccine strains and prevented the production of viable cells at reasonable cell densities. The lower levels of gene expression observed with the beta-lactamase and aerobactin promoters did not have this effect. Immunization of mice with S. typhimurium aroA strains carrying the hybrid genes expressed from these two promoters resulted in significant B subunit-specific mucosal and serum antibody responses. This suggests that such expression systems may be useful when incorporated into candidate antidysentery live oral vaccines for inducing protection against the effect of Shiga toxin in infections caused by Shigella dysenteriae 1 and other Shiga toxin-or Shiga-like toxin-producing pathogens.     

Multi-Level Socioenvironmental Contributors to Childhood Asthma in New York City: a Cluster Analysis

Childhood asthma exacerbation remains the leading cause of pediatric emergency department visits and hospitalizations and disproportionately affects Latinx and Black children, compared to non-Latinx White children in NYC. Environmental exposures and socioeconomic factors may jointly contribute to childhood asthma exacerbations; however, they are often studied separately. To better investigate the multiple contributors to disparities in childhood asthma, we compiled data on various individual and neighborhood level socioeconomic and environmental factors, including education, race/ethnicity, income disparities, gentrification, housing characteristics, built environment, and structural racism, from the NYC Department of Health’s KIDS 2017 survey and the US Census’ American Community Survey. We applied cluster analysis and logistic regression to first identify the predominant patterns of social and environmental factors experienced by children in NYC and then estimate whether children experiencing specific patterns are more likely to experience asthma exacerbations. We found that housing and built environment characteristics, such as density and age of buildings, were the predominant features to differentiate the socio-environmental patterns observed in New York City. Children living in neighborhoods with greater proportions of rental housing, high-density buildings, and older buildings were more likely to experience asthma exacerbations than other children. These findings add to the literature about childhood asthma in urban environments, and can assist efforts to target actionable policies and practices that promote health equity related to childhood asthma.