RNA-seq analysis reveals prenatal alcohol exposure is associated with placental inflammatory cells and gene expression

BACKGROUND

Fetal alcohol spectrum disorders (FASD) are the most common preventable cause of birth defects and neurodevelopmental disorders worldwide. The placenta is the crucial interface between mother and fetus. Prenatal alcohol exposure (PAE) has been shown to alter placental structure and expression of genes in bulk placental tissue samples, but prior studies have not examined effects on placental cell-type composition or taken cell-type into consideration in transcriptome analyses.

METHODS

We leveraged an existent placenta single-cell RNA-seq dataset to perform cell-type deconvolution of bulk placental RNA-seq data from 35 heavy drinking pregnant women and 33 controls in a prospective birth cohort in Cape Town, South Africa. We used bivariate analyses and multivariable adjusted linear regression models to assess the relation of PAE on inferred placental cell-type proportions. We also examined differential expression of inflammatory response genes and PAE, using multivariable adjusted linear models.

RESULTS

Deconvolution analyses showed heterogeneous placenta cell-type composition in which stromal (27 %), endothelial (26 %) and cytotrophoblasts (18 %) were the predominant cell-types. PAE around conception was associated with a higher proportion of Hofbauer cells (B = 0.51, p = 0.035) in linear models adjusted for maternal age, infant sex, and gestational age. Among the 652 inflammatory genes examined, 35 were differential expressed in alcohol exposed placentas (FDR p < 0.05).

CONCLUSIONS

Our findings suggest that heavy alcohol exposure during pregnancy can influence the proportion of fetal placental villi macrophages (Hofbauer cells) and increased expression of inflammatory genes. Future studies are needed to further characterize these effects and to assess the potential functional roles of placental inflammation in FASD.

Prenatal alcohol exposure is associated with changes in placental gene co-expression networks

Alcohol consumption during pregnancy can result in a range of adverse postnatal outcomes among exposed children. However, identifying at-risk children is challenging given the difficulty to confirm prenatal alcohol exposure and the lack of early diagnostic tools. Placental surveys present an important opportunity to uncover early biomarkers to identify those at risk. Here, we report the first transcriptome-wide evaluation to comprehensively evaluate human placental pathways altered by fetal alcohol exposure. In a prospective longitudinal birth cohort in Cape Town, South Africa, we performed bulk tissue RNAseq in placenta samples from 32 women reporting heavy drinking during pregnancy and 30 abstainers/light drinkers. Weighted gene co-expression network analysis (WGCNA) and differential gene expression analysis were performed to assess associations between fetal alcohol exposure and placental gene expression patterns at a network-wide and single gene level, respectively. The results revealed altered expression in genes related to erythropoiesis and angiogenesis, which are implicated in established postnatal phenotypes related to alcohol exposure, including disruptions in iron homeostasis, growth, and neurodevelopment. The reported findings provide insights into the molecular pathways affected by prenatal alcohol exposure and highlight the potential of placental biomarkers for detecting and understanding the effects of alcohol on fetal development.

Rationale and design of the African Cardiomyopathy and Myocarditis Registry Program: The IMHOTEP study

BACKGROUND

Heart failure (HF), the dominant form of cardiovascular disease in Africans, is mainly due to hypertension, rheumatic heart disease and cardiomyopathy. Cardiomyopathies pose a great challenge because of poor prognosis and high prevalence in low- and middle-income countries (LMICs). Little is known about the etiology and outcome of cardiomyopathy in Africa. Specifically, the role of myocarditis and the genetic causes of cardiomyopathy are largely unidentified in Africans.

METHOD

The African Cardiomyopathy and Myocarditis Registry Program (the IMHOTEP study) is a pan-African multi-centre, hospital-based cohort study, designed with the primary aim of describing the clinical characteristics, genetic causes, prevalence, management and outcome of cardiomyopathy and myocarditis in children and adults. The secondary aim is to identify barriers to the implementation of evidence-based care and provide a platform for trials and other intervention studies to reduce morbidity and mortality in cardiomyopathy. The registry consists of a prospective cohort of newly diagnosed (i.e., incident) cases and a retrospective (i.e., prevalent) cohort of existing cases from participating centres. Patients with cardiomyopathy and myocarditis will be subjected to a standardized 3-stage diagnostic process. To date, 750 patients have been recruited into the multi-centre pilot phase of the study.

CONCLUSION

The IMHOTEP study will provide comprehensive and novel data on clinical features, genetic causes, prevalence and outcome of African children and adults with all forms of cardiomyopathy and myocarditis in Africa. Based on these findings, appropriate strategies for management and prevention of the cardiomyopathies in LMICs are likely to emerge.

Effects of Plasma Choline Concentrations on Placental Development and Fetal Growth, With Potential Mechanistic Roles of Imprinted Genes

Objectives

Imprinted genes are epigenetically regulated and play critical roles in placental development and fetal growth. We aimed to examine (1) the impact of maternal one-carbon (methyl donor) nutrition on placental imprinted gene expression, placental development, and fetal growth; (2) whether imprinted gene expression alterations mediate effects of one-carbon nutrition on placental development and fetal growth; (3) interaction effects between one-carbon nutrients and imprinted genes in placental development and fetal growth.

Methods

Histopathology and expression of 109 imprinted genes (Nanostring) were assessed in placentas from 101 women recruited at initiation of antenatal care in a prospective cohort study examining developmental effects of prenatal alcohol exposure in South Africa. Women were interviewed prenatally about demographics, alcohol, smoking, and drug use, and erythrocyte folate, serum vitamin B12, and plasma choline concentrations were assayed at recruitment. Infant weight and height were assessed at age 2 wk.

Results

In limma tests, women with plasma choline concentrations below the median had lower placental expression of EPS15, IGF2R, LINC00657, SGCE, ZC3H12C, and ZNF264 than women above the median (p &lt; .05, FDR &lt; .10). In regression models adjusted for potential confounders (maternal age, gravidity, education, alcohol and drug use), plasma choline (μM) was associated with larger placental weight (g) (B = 14.0(1.9, 26.2)) and reduced maternal vascular underperfusion (MVU) prevalence (B = −.07(−.12, −.02). In causal inference analyses, there were trends for mediation of the relation between choline and MVU by decreased LINC00657, ZC3H12C, and ZNF264 expression. In regression models examining plasma choline X imprinted gene expression interaction effects, choline modified relations of EPS15, ZC3H12C, and ZNF264 to placental weight and fetal growth.

Conclusions

Maternal plasma choline was associated with decreased placental expression of 6 imprinted genes, 3 of which may mediate effects of choline on placental development. Choline modified effects of 3 genes on placental and fetal growth. These findings suggest maternal choline status may impact placental and fetal development, with imprinted genes playing mechanistic roles.

Funding Sources

NIH/NIAAA; Lycaki-Young Fund.

Prenatal alcohol-related alterations in maternal, placental, neonatal, and infant iron homeostasis

BACKGROUND

Prenatal alcohol exposure (PAE) is associated with postnatal iron deficiency (ID), which has been shown to exacerbate deficits in growth, cognition, and behavior seen in fetal alcohol spectrum disorders. However, the mechanisms underlying PAE-related ID remain unknown.

OBJECTIVES

We aimed to examine biochemical measures of iron homeostasis in the mother, placenta, neonate, and 6.5-month-old infant.

METHODS

In a prenatally recruited, prospective longitudinal birth cohort in South Africa, 206 gravidas (126 heavy drinkers and 80 controls) were interviewed regarding alcohol, cigarette, and drug use and diet at 3 prenatal visits. Hemoglobin, ferritin, and soluble transferrin receptor (sTfR) were assayed twice during pregnancy and urinary hepcidin:creatinine was assayed once. Infant ferritin and hemoglobin were measured at 2 weeks and 6.5 months and sTfR was measured at 6.5 months. Histopathological examinations were conducted on 125 placentas and iron transport assays (iron regulatory protein-2, transferrin receptor-1, divalent metal transporter-1, ferroportin-1, and iron concentrations) were conducted on 63.

RESULTS

In multivariable regression models, prenatal drinking frequency (days/week) was related to higher maternal hepcidin and to sequestration of iron into storage at the expense of erythropoiesis in mothers and neonates, as evidenced by a lower hemoglobin (g/dL)-to-log(ferritin) (ug/L) ratio [mothers: raw regression coefficient (β) = -0.21 (95% CI: -0.35 to -0.07); neonates: β = -0.15 (95% CI: -0.24 to -0.06)]. Drinking frequency was also related to decreased placental ferroportin-1:transferrin receptor-1 (β = -0.57 for logged values; 95% CI: -1.03 to -0.10), indicating iron-restricted placental iron transport. At 6.5 months, drinking frequency was associated with lower hemoglobin (β = -0.18; 95% CI: -0.33 to -0.02), and increased prevalences of ID (β = 0.09; 95% CI: 0.02-0.17) and ID anemia (IDA) (β = 0.13; 95% CI: 0.04-0.23). In causal inference analyses, the PAE-related increase in IDA was partially mediated by decreased neonatal hemoglobin:log(ferritin), and the decrease in neonatal hemoglobin:log(ferritin) was partially mediated by decreased maternal hemoglobin:log(ferritin).

CONCLUSIONS

In this study, greater PAE was associated with an unfavorable profile of maternal-fetal iron homeostasis, which may play mechanistic roles in PAE-related ID later in infancy.

Drug-Penetration Gradients Associated with Acquired Drug Resistance in Patients with Tuberculosis

RATIONALE

Acquired resistance is an important driver of multidrug-resistant tuberculosis (TB), even with good treatment adherence. However, exactly what initiates the resistance and how it arises remain poorly understood.

OBJECTIVES

To identify the relationship between drug concentrations and drug susceptibility readouts (minimum inhibitory concentrations [MICs]) in the TB cavity.

METHODS

We recruited patients with medically incurable TB who were undergoing therapeutic lung resection while on treatment with a cocktail of second-line anti-TB drugs. On the day of surgery, antibiotic concentrations were measured in the blood and at seven prespecified biopsy sites within each cavity. Mycobacterium tuberculosis was grown from each biopsy site, MICs of each drug identified, and whole-genome sequencing performed. Spearman correlation coefficients between drug concentration and MIC were calculated.

MEASUREMENTS AND MAIN RESULTS

Fourteen patients treated for a median of 13 months (range, 5-31 mo) were recruited. MICs and drug resistance-associated single-nucleotide variants differed between the different geospatial locations within each cavity, and with pretreatment and serial sputum isolates, consistent with ongoing acquisition of resistance. However, pretreatment sputum MIC had an accuracy of only 49.48% in predicting cavitary MICs. There were large concentration-distance gradients for each antibiotic. The location-specific concentrations inversely correlated with MICs (P < 0.05) and therefore acquired resistance. Moreover, pharmacokinetic/pharmacodynamic exposures known to amplify drug-resistant subpopulations were encountered in all positions.

CONCLUSIONS

These data inform interventional strategies relevant to drug delivery, dosing, and diagnostics to prevent the development of acquired resistance. The role of high intracavitary penetration as a biomarker of antibiotic efficacy, when assessing new regimens, requires clarification.

Spatial Network Mapping of Pulmonary Multidrug-Resistant Tuberculosis Cavities Using RNA Sequencing

Rationale: There is poor understanding about protective immunity and the pathogenesis of cavitation in patients with tuberculosis.Objectives: To map pathophysiological pathways at anatomically distinct positions within the human tuberculosis cavity.Methods: Biopsies were obtained from eight predetermined locations within lung cavities of patients with multidrug-resistant tuberculosis undergoing therapeutic surgical resection (n = 14) and healthy lung tissue from control subjects without tuberculosis (n = 10). RNA sequencing, immunohistochemistry, and bacterial load determination were performed at each cavity position. Differentially expressed genes were normalized to control subjects without tuberculosis, and ontologically mapped to identify a spatially compartmentalized pathophysiological map of the cavity. In silico perturbation using a novel distance-dependent dynamical sink model was used to investigate interactions between immune networks and bacterial burden, and to integrate these identified pathways.Measurements and Main Results: The median (range) lung cavity volume on positron emission tomography/computed tomography scans was 50 cm3 (15-389 cm3). RNA sequence reads (31% splice variants) mapped to 19,049 annotated human genes. Multiple proinflammatory pathways were upregulated in the cavity wall, whereas a downregulation "sink" in the central caseum-fluid interface characterized 53% of pathways including neuroendocrine signaling, calcium signaling, triggering receptor expressed on myeloid cells-1, reactive oxygen and nitrogen species production, retinoic acid-mediated apoptosis, and RIG-I-like receptor signaling. The mathematical model demonstrated that neuroendocrine, protein kinase C-θ, and triggering receptor expressed on myeloid cells-1 pathways, and macrophage and neutrophil numbers, had the highest correlation with bacterial burden (r > 0.6), whereas T-helper effector systems did not.Conclusions: These data provide novel insights into host immunity to Mycobacterium tuberculosis-related cavitation. The pathways defined may serve as useful targets for the design of host-directed therapies, and transmission prevention interventions.

Paradoxical respiratory failure due to cryptococcal pneumonia after amphotericin B treatment for HIV-associated cryptococcal meningitis

We present a 27-year-old lady with HIV-1 infection who died due to rapidly worsening respiratory failure one day after commencing amphotericin B deoxycholate therapy for cryptococcal meningitis. Chest x-ray appearances were consistent with pneumocystis pneumonia but post mortem examination showed evidence of severe necrotizing cryptococcal pneumonia. Cryptococcal pneumonia is an underrecognized condition and should be considered in the differential of patients with HIV-1 infection and low CD4 count who develop respiratory symptoms.

Alcohol, Methamphetamine, and Marijuana Exposure Have Distinct Effects on the Human Placenta

BACKGROUND

Animal studies have demonstrated adverse effects of prenatal alcohol exposure on placental development, but few studies have examined these effects in humans. Little is known about effects of prenatal exposure to methamphetamine, marijuana, and cigarette smoking on placental development.

METHODS

Placentas were collected from 103 Cape Coloured (mixed ancestry) pregnant women recruited at their first antenatal clinic visit in Cape Town, South Africa. Sixty-six heavy drinkers and 37 nondrinkers were interviewed about their alcohol, cigarette smoking, and drug use at 3 antenatal visits. A senior pathologist, blinded to exposure status, performed comprehensive pathology examinations on each placenta using a standardized protocol. In multivariable regression models, effects of prenatal exposure were examined on placental size, structure, and presence of infections and meconium.

RESULTS

Drinkers reported a binge pattern of heavy drinking, averaging 8.0 drinks/occasion across pregnancy on 1.4 d/wk. 79.6% smoked cigarettes; 22.3% used marijuana; and 17.5% used methamphetamine. Alcohol exposure was related to decreased placental weight and a smaller placenta-to-birthweight ratio. By contrast, methamphetamine was associated with larger placental weight and a larger placenta-to-birthweight ratio. Marijuana was also associated with larger placental weight. Alcohol exposure was associated with increased risk of placental hemorrhage. Prenatal alcohol, drug, and cigarette use were not associated with chorioamnionitis, villitis, deciduitis, or maternal vascular underperfusion. Alcohol and cigarette smoking were associated with a decreased risk of intrauterine passing of meconium, a sign of acute fetal stress and/or hypoxia; methamphetamine, with an increased risk.

CONCLUSIONS

This is the first human study to show that alcohol, methamphetamine, and marijuana were associated with distinct patterns of pathology, suggesting different mechanisms mediating their effects on placental development. Given the growing body of evidence linking placental abnormalities to neurodevelopmental deficits, these findings may be important in the long-term teratogenic effects of prenatal alcohol and drug exposure.

Relationship Between HIV Coinfection, Interleukin 10 Production, and Mycobacterium tuberculosis in Human Lymph Node Granulomas

BACKGROUND

 Human immunodeficiency virus type 1 (HIV)-infected persons are more susceptible to tuberculosis than HIV-uninfected persons. Low peripheral CD4+ T-cell count is not the sole cause of higher susceptibility, because HIV-infected persons with a high peripheral CD4+ T-cell count and those prescribed successful antiretroviral therapy (ART) remain more prone to active tuberculosis than HIV-uninfected persons. We hypothesized that the increase in susceptibility is caused by the ability of HIV to manipulate Mycobacterium tuberculosis-associated granulomas.

METHODS

 We examined 71 excised cervical lymph nodes (LNs) from persons with HIV and M. tuberculosis coinfection, those with HIV monoinfection, and those with M. tuberculosis monoinfection with a spectrum of peripheral CD4+ T-cell counts and ART statuses. We quantified differences in M. tuberculosis levels, HIV p24 levels, cellular response, and cytokine presence within granulomas.

RESULTS

 HIV increased M. tuberculosis numbers and reduced CD4+ T-cell counts within granulomas. Peripheral CD4+ T-cell depletion correlated with granulomas that contained fewer CD4+ and CD8+ T cells, less interferon γ, more neutrophils, more interleukin 10 (IL-10), and increased M. tuberculosis numbers. M. tuberculosis numbers correlated positively with IL-10 and interferon α levels and fewer CD4+ and CD8+ T cells. ART reduced IL-10 production.

CONCLUSIONS

 Peripheral CD4+ T-cell depletion correlated with increased M. tuberculosis presence, increased IL-10 production, and other phenotypic changes within granulomas, demonstrating the HIV infection progressively changes these granulomas.

Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis

In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for Mycobacterium tuberculosis in the lymph nodes of patients with tuberculosis. In cultured primary human LECs (hLECs), we determined that M. tuberculosis replicates both in the cytosol and within autophagosomes, but the bacteria failed to replicate when the virulence locus RD1 was deleted. Activation by IFN-γ induced a cell-autonomous response in hLECs via autophagy and NO production that restricted M. tuberculosis growth. Thus, depending on the activation status of LECs, autophagy can both promote and restrict replication. Together, these findings reveal a previously unrecognized role for hLECs and autophagy in tuberculosis pathogenesis and suggest that hLECs are a potential niche for M. tuberculosis that allows establishment of persistent infection in lymph nodes.

A clinicopathological cohort study of liver pathology in 301 patients with human immunodeficiency virus/acquired immune deficiency syndrome

Liver disease complicates human immunodeficiency virus (HIV)/acquired immune deficiency syndrome; however, liver pathology data are limited, particularly from high HIV prevalence countries. We investigated the spectrum and clinicopathological correlates of liver pathology in a high HIV burden setting. In a single-center study, all HIV/acquired immune deficiency syndrome patients with complete clinical and demographic data who underwent liver biopsy were analyzed and clinicopathologically assessed by hepatologists and one of two experienced liver pathologists. We evaluated 301 patients, with a median age of 34 (interquartile range 29-40) years. Women (n = 143) were younger than men (n = 158), with a median age of 33 (interquartile range 28-37) versus 35 (interquartile range 31-41) years, P = 0.001. The majority, 76.1%, were black African. Median CD4 at time of biopsy was 127 (52-260) cells/mm(3) . Drug-induced liver injury was the predominant finding (42.2%), followed by granulomatous inflammation (29%), steatosis/steatohepatitis (19.3%), hepatitis B (19%), and hepatitis C coinfection (3.3%), with more than one pathology in 16.2%. With granulomatous inflammation, 52% met the criteria for tuberculosis immune reconstitution syndrome. By univariate analysis, cotrimoxazole and antiretroviral therapy conferred risk for drug injury (odds ratio [OR] = 2.78 [1.72-4.48], P < 0.001; OR = 1.69 [1.06-2.68], P = 0.027). In multivariate analysis, cotrimoxazole was associated with a cholestatic or ductopenic injury (OR = 7.05 [2.50-19.89], P < 0.001; OR = 17.6 [3.26-95.3], P < 0.0001); efavirenz was associated with nonspecific hepatitis or submassive necrosis (OR = 4.3 [1.92-9.83], P < 0.001; OR = 10.46 [2.7-40.5], P < 0.001). Cholestatic injury was associated with female gender and a CD4 of >200 cells/mm(3) , and submassive necrosis was associated with younger age. Hepatitis B demonstrated no association.

CONCLUSION

In a high HIV burden area, drug-induced liver injury due to antiretroviral therapy and cotrimoxazole was a frequent clinicopathological finding; Mycobacterium tuberculosis was the leading opportunistic infection, with more than half of patients fulfilling criteria for tuberculosis immune reconstitution syndrome; liver biopsy remains a useful diagnostic procedure in this setting.

HIV associated Lymphocytic Interstitial Pneumonia: a clinical, histological and radiographic study from an HIV endemic resource-poor setting

Background

There is a paucity of clinical and histopathological data about HIV-associated lymphocytic interstitial pneumonitis (LIP) in adults from HIV endemic settings. The role of Ebstein-Barr virus (EBV) in the pathogenesis remains unclear.

Methods

We reviewed the clinical, radiographic and histopathological features of suspected adult LIP cases at the Groote Schuur Hospital, Cape Town South Africa, over a 6 year period. Archived tissue sections were stained for CD3, CD4, CD8, CD20 and LMP-1 antigen (an EBV marker).

Results

42 cases of suspected LIP(100% HIV-infected) were identified. 75% of patients were empirically treated for TB prior to being referred to the chest service for further investigation. Tissue samples were obtained using trans-bronchial biopsy. 13/42 were classified as definite LIP (lymphocytic infiltrate with no alternative diagnosis), 19/42 probable LIP (lymphocytic infiltrate but evidence of anthracosis or fibrosis) and 10 as non-LIP (alternative histological diagnosis). Those with definite LIP were predominantly young females (85%) with a median CD4 count of 194 (IQR 119–359). Clinical or radiological features had poor predictive value for LIP. Histologically, the lymphocytic infiltrate comprised mainly B cells and CD8 T cells. The frequency of positive EBV LMP-1 antigen staining was similar in definite and non- LIP patients [(2/13 (15%) vs. 3/10 (30%); p = 0.52].

Conclusions

In a HIV endemic setting adult HIV-associated LIP occurs predominantly in young women. The diagnosis can often be made on transbronchial biopsy and is characterized by a predominant CD8 T cell infiltrate. No association with EBV antigen was found.

Autopsy observations in lethal short-rib polydactyly syndromes

The short rib-polydactyly syndromes are a heterogeneous group of lethal autosomal recessive disorders (SRP I-IV), which result from cellular ciliary dysfunction during embryogenesis. Diagnosis is conventionally based on radiographic imaging. Since 1976, postmortem investigations of 5 affected fetuses or stillbirths have been undertaken and the visceral abnormalities have been documented. These anomalies are discussed in the context of prenatal differential diagnosis and prognostication following imaging in pregnancy and at autopsy following miscarriage or stillbirth.

Prevalence of myocarditis and cardiotropic virus infection in Africans with HIV-associated cardiomyopathy, idiopathic dilated cardiomyopathy and heart transplant recipients: a pilot study: cardiovascular topic

Background:

The prevalence of myocarditis and cardiotropic viral infection in human immunodeficiency virus (HIV)-associated cardiomyopathy is unknown in Africa.

Methods

Between April 2002 and December 2007, we compared the prevalence of myocarditis and cardiotropic viral genomes in HIV-associated cardiomyopathy cases with HIV-negative idiopathic dilated cardiomyopathy patients (i.e. negative controls for immunodeficiency) and heart transplant recipients (i.e. positive controls for immunodeficiency) who were seen at Groote Schuur Hospital, Cape Town, South Africa. Myocarditis was sought on endomyocardial biopsy using the imunohistological criteria of the World Heart Federation in 33 patients, 14 of whom had HIV-associated cardiomyopathy, eight with idiopathic dilated cardiomyopathy and 11 heart transplant recipients.

Results

Myocarditis was present in 44% of HIV-associated cardiomyopathy cases, 36% of heart transplant recipients, and 25% of participants with idiopathic dilated cardiomyopathy. While myocarditis was acute in 50% of HIV- and heart transplant-associated myocarditis, it was chronic in all those with idiopathic dilated cardiomyopathy. Cardiotropic viral infection was present in all HIV-associated cardiomyopathy and idiopathic dilated cardiomyopathy cases, and in 90% of heart transplant recipients. Multiple viruses were identified in the majority of cases, with HIV-associated cardiomyopathy, heart transplant recipients and idiopathic dilated cardiomyopathy patients having an average of 2.5, 2.2 and 1.1 viruses per individual, respectively.

Conclusions

Acute myocarditis was present in 21% of cases of HIV-associated cardiomyopathy, compared to none of those with idiopathic dilated cardiomyopathy. Infection with multiple cardiotropic viruses may be ubiquitous in Africans, with a greater burden of infection in acquired immunodeficiency states.

Predictive genetic testing in children: constitutional mismatch repair deficiency cancer predisposing syndrome

Biallelic germline mutations in mismatch repair genes predispose to constitutional mismatch repair deficiency syndrome (CMMR-D). The condition is characterized by a broad spectrum of early-onset tumors, including hematological, brain and bowel and is frequently associated with features of Neurofibromatosis type 1. Few definitive screening recommendations have been suggested and no published reports have described predictive testing. We report on the first case of predictive testing for CMMR-D following the identification of two non-consanguineous parents, with the same heterozygous mutation in MLH1: c.1528C > T. The genetic counseling offered to the family, for their two at-risk daughters, is discussed with a focus on the ethical considerations of testing children for known cancer-causing variants. The challenges that are encountered when reporting on heterozygosity in a child younger than 18 years (disclosure of carrier status and risk for Lynch syndrome), when discovered during testing for homozygosity, are addressed. In addition, the identification of CMMR-D in a three year old, and the recommended clinical surveillance that was proposed for this individual is discussed. Despite predictive testing and presymptomatic screening, the sudden death of the child with CMMR-D syndrome occurred 6 months after her last surveillance MRI. This report further highlights the difficulty of developing guidelines, as a result of the rarity of cases and diversity of presentation.

Characterisation of innate fungal recognition in the lung

The innate recognition of fungi by leukocytes is mediated by pattern recognition receptors (PRR), such as Dectin-1, and is thought to occur at the cell surface triggering intracellular signalling cascades which lead to the induction of protective host responses. In the lung, this recognition is aided by surfactant which also serves to maintain the balance between inflammation and pulmonary function, although the underlying mechanisms are unknown. Here we have explored pulmonary innate recognition of a variety of fungal particles, including zymosan, Candida albicans and Aspergillus fumigatus, and demonstrate that opsonisation with surfactant components can limit inflammation by reducing host-cell fungal interactions. However, we found that this opsonisation does not contribute directly to innate fungal recognition and that this process is mediated through non-opsonic PRRs, including Dectin-1. Moreover, we found that pulmonary inflammatory responses to resting Aspergillus conidia were initiated by these PRRs in acidified phagolysosomes, following the uptake of fungal particles by leukocytes. Our data therefore provides crucial new insights into the mechanisms by which surfactant can maintain pulmonary function in the face of microbial challenge, and defines the phagolysosome as a novel intracellular compartment involved in the innate sensing of extracellular pathogens in the lung.

Atherosclerotic lesions in the thoracic aorta: a South African anatomical and histological mortuary study

BACKGROUND

Worldwide, the prevalence of cardiovascular diseases such as atherosclerosis is on the increase. Younger people may be especially vulnerable owing to their exposure to risk factors such as drug abuse and HIV.

METHODS

The thoracic aortas of 149 South Africans under the age of 50 years were collected at the Salt River Mortuary, Cape Town, and examined macroscopically and microscopically for evidence of anomalies. The sample comprised predominantly males, and included black, coloured and white individuals.

RESULTS

A significantly higher level of macroscopic pathology was found in coloured males, although overall prevalence of pathology in this sample was lower than expected. A positive association was also found between body mass index and vascular pathology in the black and coloured population groups. Microscopic anomalies were common and present at high levels, irrespective of age and racial grouping.

CONCLUSIONS

The widespread prevalence of microscopic anomalies in all groups suggests that these are normal variations that result from haemodynamic forces. The higher prevalence of atherosclerotic lesions in coloured males, however, probably results from specific genetic conditions such as hypercholesterolaemia or lifestyle factors such as diet or tik abuse. The findings suggest that coloured individuals may be at increased risk of developing cardiovascular disease.

Solid pseudopapillary epithelial neoplasm--a rare but curable pancreatic tumour in young women

BACKGROUND

Solid pseudopapillary epithelial neoplasms (SPENs) of the pancreas are rare but curable tumours that have a low-grade malignant potential and occur almost exclusively in young women, with an excellent prognosis after complete resection. This study examines the clinicopathological characteristics of these tumours and evaluates the role of surgery in relation to their size and location.

STUDY DESIGN

We reviewed the pre-, intra- and postoperative data on 21 patients with SPENs who underwent resection during a 30-year period. Data including demographic information, presenting symptoms and signs, extent of operation, histology, tumour markers and postoperative complications were evaluated to establish the optimal surgical management.

RESULTS

All 21 tumours occurred in women (mean age 24.6 years, range 13-51 years). Sixteen patients presented with nonspecific abdominal complaints and a palpable abdominal mass, in 1 patient the tumour was found during emergency laparotomy for a complicated ovarian cyst, 1 patient presented with severe abdominal pain and shock due to a ruptured tumour, and in 3 patients the tumour was detected incidentally during imaging. The correct pre-operative diagnosis of SPEN was made in 10 patients. Incorrect preoperative diagnoses included hydatid cyst (3 patients), mesenteric cyst (2), pancreatic cystadenoma (2), ovarian cysts (1), islet cell tumour of the pancreas (1), and cavernous haemangioma of the liver (1). The mean diameter of the tumours was 12.5 cm (range 8 - 20 cm), and they occurred in the head (8), neck (5), body (2), and tail (6) of the pancreas. All SPENs were resected. Five patients had a pylorus-preserving pancreaticoduodenectomy, 4 a central pancreatectomy with distal pancreaticogastrostomy, 8 a distal pancreatectomy, 3 a local resection and one a total pancreatectomy and portal vein graft. In 1 patient, 2 liver metastases were resected in addition to the pancreatic primary tumour. The patient who presented in shock with tumour rupture and bleeding into the lesser sac later died of multiple organ failure after successful resection. Postoperative complications included a stricture at the hepaticojejunostomy after pancreaticoduodenectomy, which resolved after stenting, and a pancreatic duct fistula after local tumour resection, which required a distal pancreatectomy. Other complications were bleeding (2 patients) requiring re-operation and intraabdominal fluid collections requiring percutaneous drainage (3) or operation (1). Mean postoperative hospital stay was 16 days (range 6 - 40 days). Twenty patients are alive and well without recurrence, including the patient with metastases, with a mean follow-up of 6.6 years (range 6 months-15 years).

CONCLUSIONS

This study demonstrated that SPENs of the pancreas are uncommon, but should be considered in the differential diagnosis of a cystic mass of the pancreas in a young woman. Despite the indolent biological behaviour of SPENs, most patients required major pancreatic resection. Surgery is curative regardless of the size or location of the tumour. Metastases are rare, as is recurrence after complete surgical resection.

Induction of ER stress in macrophages of tuberculosis granulomas

Background

The endoplasmic reticulum (ER) stress pathway known as the Unfolded Protein Response (UPR) is an adaptive survival pathway that protects cells from the buildup of misfolded proteins, but under certain circumstances it can lead to apoptosis. ER stress has been causally associated with macrophage apoptosis in advanced atherosclerosis of mice and humans. Because atherosclerosis shares certain features with tuberculosis (TB) with regard to lesional macrophage accumulation, foam cell formation, and apoptosis, we investigated if the ER stress pathway is activated during TB infection.

Principal Findings

Here we show that ER stress markers such as C/EBP homologous protein (CHOP; also known as GADD153), phosphorylated inositol-requiring enzyme 1 alpha (Ire1α) and eukaryotic initiation factor 2 alpha (eIF2α), and activating transcription factor 3 (ATF3) are expressed in macrophage-rich areas of granulomas in lungs of mice infected with virulent Mycobacterium tuberculosis (Mtb). These areas were also positive for numerous apoptotic cells as assayed by TUNEL. Microarray analysis of human caseous TB granulomas isolated by laser capture microdissection reveal that 73% of genes involved in the UPR are upregulated at the mRNA transcript level. The expression of two ER stress markers, ATF3 and CHOP, were also increased in macrophages of human TB granulomas when assayed by immunohistochemistry. CHOP has been causally associated with ER stress-induced macrophage apoptosis. We found that apoptosis was more abundant in granulomas as compared to non-granulomatous tissue isolated from patients with pulmonary TB, and apoptosis correlated with CHOP expression in areas surrounding the centralized areas of caseation.

Conclusions

In summary, ER stress is induced in macrophages of TB granulomas in areas where apoptotic cells accumulate in mice and humans. Although macrophage apoptosis is generally thought to be beneficial in initially protecting the host from Mtb infection, death of infected macrophages in advanced granulomas might favor dissemination of the bacteria. Therefore future work is needed to determine if ER-stress is causative for apoptosis and plays a role in the host response to infection.

Dyssegmental dysplasia with bone entrapment and visceral ramifications

A stillborn neonate had the typical clinical and radiologic manifestations of dyssegmental dysplasia, an autosomal recessive genetic disorder. The diagnosis was supported by histologic demonstration of the characteristic ballooned chondrocytes in the growth plate and spaces filled with mucoid material in the resting cartilage. Autopsy revealed entrapment of the femoral heads by bone overgrowth in the acetabulum. This notable feature, which has apparently not previously been documented, explained the articular rigidity, which is a significant clinical manifestation. Horizontal grooves on the anterior surface of the spleen were another unusual finding. Our observations further emphasize the importance of comprehensive autopsy in the determination of the pathogenesis of the clinical features and the range of phenotypic expression of an underlying mutation in an unusual genetic disorder.

Tetraphocomelia with the Waardenburg syndrome and multiple malformations

A male infant delivered spontaneously at the 29th week of pregnancy had gross tetraphocomelia and features of the Waardenburg syndrome. There were no relevant factors in the pregnancy nor family history. It is possible that microdeletions or contiguous gene defects are involved in the pathogenesis of these malformations.

Visceral manifestations of hypochondrogenesis

Autopsy of a stillborn neonate with hypochondrogenesis revealed severe cardiac abnormalities and extensive diverticulosis of the proximal region of the small intestine. Visceral ramifications are unusual in hypochondrogenesis; they may reflect heterogeneity of the intramolecular defect in the COL2A1 gene that codes for the achondrogenesis type II-hypochondrogenesis spectrum of disorders.

Stroke in patients with human immunodeficiency virus infection

OBJECTIVE

To report the nature of stroke in patients infected with human immunodeficiency virus (HIV) in a region with high HIV seroprevalence and describe HIV associated vasculopathy.

METHODS

Patients with first ever stroke, infected with HIV and prospectively included in the stroke register of the Groote Schuur Hospital/University of Cape Town stroke unit were identified and reviewed.

RESULTS

Between 2000 and 2006, 67 of the 1087 (6.1%) stroke patients were HIV infected. Of these, 91% (n = 61) were younger than 46 years. Cerebral infarction occurred in 96% (n = 64) of the HIV positive patients and intracerebral haemorrhage in 4% (n = 3). HIV infected young stroke patients did not demonstrate hypertension, diabetes, hyperlipidaemia or smoking as significant risk factors for ischaemic stroke. Infection as a risk factor for stroke was significantly more common in HIV positive patients (p = 0.018, OR 6.4, CI 3.1 to 13.2). In 52 (81%) patients with ischaemic stroke, an aetiology was determined. Primary aetiologies comprised infectious meningitides/vasculitides in 18 (28%) patients, coagulopathy in 12 (19%) patients and cardioembolism in nine (14%) patients. Multiple aetiologies were present in seven (11%) patients with ischaemic stroke. HIV associated vasculopathy was identified in 13 (20%) patients. The HIV associated vasculopathy manifested either extracranially (seven patients) as total or significant carotid occlusion or intracranially (six patients) as medium vessel occlusion, with or without fusiform aneurysmal dilation, stenosis and vessel calibre variation.

CONCLUSION

Investigation of HIV infected patients presenting with stroke will determine an aetiology in the majority of patients. In our cohort, 20% of patients demonstrated evidence of an HIV associated vasculopathy.

Osteogenesis imperfecta and holoprosencephaly

A 17-week female fetus had severe osteogenesis imperfecta and gross holoprosencephaly. This unusual combination has not previously been documented. No obvious environmental or genetic determinants were present.

Poikiloderma, tendon contracture and pulmonary fibrosis: a new autosomal dominant syndrome?

Members of two generations of a South African family have a unique syndrome comprising poikiloderma, tendon contractures and progressive pulmonary fibrosis. The condition is clinically important as the skin changes, which involve the face, have considerable cosmetic impact, while lung involvement is potentially lethal in adulthood. Skin manifestations which facilitate diagnosis include facial telangiectasia, mottled hypo- and hyperpigmentation, papules and epidermal atrophy. The scalp, facial and body hair are fine and scanty. The tendon contractures lead to progressive digital flexion deformities and abnormalities of the ankles and feet, with disturbance of gait. Pulmonary involvement manifests as progressive dyspnoea. Pedigree data are compatible with an autosomal dominant mode of transmission. Poikiloderma of Weary is characterized by linear sclerotic and fibrous bands and not tendon contractures and is not associated with potentially lethal pulmonary fibrosis. Rather than name this disorder a variant of Weary syndrome, it might be prudent to use as an umbrella title one composed by Weary himself: 'hereditary sclerosing poikiloderma' (HSP), under which variants such as HSP Weary type, HSP with cardiac involvement (aortic stenosis described as inconsistently associated with Weary syndrome) and HSP with tendon/pulmonary involvement (current family) may be classified. The manifestations in this family differ from other poikilodermata and, to the best of our knowledge, have not been previously documented.

Hepatic granulomas

Hepatic granulomas were present in 3.7% of liver biopsies from a 6-year Greek study. The majority of cases were due to autoimmune disease (primary biliary cirrhosis), followed by sarcoidosis and idiopathic causes. Infections were infrequent. This profile is similar to series from the USA, Ireland and Scotland. It contrasts dramatically with series from Turkey and Saudi Arabia where infectious aetiologies form the majority of cases, and autoimmune cases are not reported. Tuberculosis and schistosomiasis are the most prevalent infections. The patient sex and age differ strikingly in some series. The series were tabulated for easy comparison.

Stroke Caused by Human Immunodeficiency Virus–Associated Intracranial Large-Vessel Aneurysmal Vasculopathy

BACKGROUND

Intracranial aneurysms related to human immunodeficiency virus (HIV) infection have been well described in pediatric patients but not in adults.

OBJECTIVE

To describe a case of intracranial large-vessel aneurysmal vasculopathy causing stroke in a 27-year-old HIV-infected woman.

DESIGN

Comparison of clinical and histological data with previously published cases.

SETTING

A referral hospital stroke unit. Patient A 27-year-old HIV-infected woman presenting with stroke; neuroimaging demonstrated fusiform aneurysmal dilation of the left internal carotid and the left middle cerebral artery and its branches.

RESULTS

Autopsy showed degeneration of the elastic lamina, myxoid degeneration, and medial atrophy, causing consequent ectasia of the involved intracranial vessels.

CONCLUSION

Aneurysmal dilation of the intracranial arteries occurs in HIV-infected adults, but the pathogenic role of HIV remains unknown.

Four decades of conjoined twins at Red Cross Children's Hospital--lessons learned

Conjoined twins represent a rare but fascinating congenital condition, the aetiology of which remains obscure. Over the past four decades, the paediatric surgeons at Red Cross Children's Hospital have been involved in the management of 46 pairs of conjoined twins, of which 33 have been symmetrical and 12 asymmetrical. Seventeen symmetrical twins have undergone separation with 22 children (65%) surviving; all of the live asymmetrical twins survived separation. We describe the important features of this unique cohort, outline our approach to management and present the results of this approach. We consider some of the ethical and moral dilemmas we have confronted, and discuss the prenatal diagnosis, obstetric implications and postnatal care of these children, including the relevant investigations and anaesthetic and surgical management. Specific aspects related to the cardiovascular system, hepatobiliary and gastrointestinal tracts, urogenital tract, central nervous system and musculoskeletal system are highlighted.

Preterm prelabour rupture of the membranes before 28 weeks: better than feared outcome of expectant management in Africa

OBJECTIVE

To document the prognosis after conservative management of patients with membrane rupture at gestations less than 28 weeks.

STUDY DESIGN

Prospective observational study of 78 women with confirmed membrane rupture at less than 28 weeks gestation, managed conservatively. Antibiotics were given from the time of membrane rupture till delivery. Patients were delivered if clinical infection supervened, there was fetal compromise, spontaneous labour ensued or if the pregnancy continued to 34 completed weeks gestation.

RESULTS

The mean gestational age at membrane rupture was 23.3+/-3.17 weeks (16.5-27.8) and the median 24 weeks. Mean latency period was 24.1+/-29.1 days (1.5-154) with a median of 12.5 days. Eight women (10%) delivered between 24 and 48 h, 25 (32%) within 7 days and 55 (70%) within 1 month. Of note is that 23 patients (30%) had latency periods of greater than 1 month. The mean gestational age at delivery was 26.7+/-3.92 weeks. Overall of the 78 women there were 81 fetuses delivered, of which 35 (43%) survived. Survival was related to latency period, birth weight and gestational age at delivery. Sixteen women (20%) developed chorioamnionitis. There was no increase in the incidence of clinical infection with increasing latency period. Compression limb abnormalities occurred in 17% of neonates and lung hypoplasia in 18%.

CONCLUSION

Conservative management of patients with very preterm prelabour membrane rupture offers a survival rate of at least 40% with no serious complications in a study of 78 women.

Mycobacterium tuberculosis growth at the cavity surface: a microenvironment with failed immunity

Protective immunity against pulmonary tuberculosis (TB) is characterized by the formation in the lungs of granulomas consisting of macrophages and activated T cells producing tumor necrosis factor alpha and gamma interferon, both required for the activation of the phagocytes. In 90% of immunocompetent humans, this response controls the infection. To understand why immunity fails in the other 10%, we studied the lungs of six patients who underwent surgery for incurable TB. Histologic examination of different lung lesions revealed heterogeneous morphology and distribution of acid-fast bacilli; only at the surface of cavities, i.e., in granulomas with a patent connection to the airways, were there numerous bacilli. The mutation profile of the isolates suggested that a single founder strain of Mycobacterium tuberculosis may undergo genetic changes during treatment, leading to acquisition of additional drug resistance independently in discrete physical locales. Additional drug resistance was preferentially observed at the cavity surface. Cytokine gene expression revealed that failure to control the bacilli was not associated with a generalized suppression of cellular immunity, since cytokine mRNA was up regulated in all lesions tested. Rather, a selective absence of CD4(+) and CD8(+) T cells was noted at the luminal surface of the cavity, preventing direct T-cell-macrophage interactions at this site, probably allowing luminal phagocytes to remain permissive for bacillary growth. In contrast, in the perinecrotic zone of the granulomas, the two cell types colocalized and bacillary numbers were substantially lower, suggesting that in this microenvironment an efficient bacteriostatic or bactericidal phagocyte population was generated.

Evaluation of peripheral blood CD4 and CD8 lymphocyte subsets, CD69 expression and histologic rejection grade as diagnostic markers for the presence of cardiac allograft rejection

We investigated the dynamics of the CD4+ and CD8+ lymphocyte subsets, and the expression of activation markers in cardiac transplant recipients. We tested 132 peripheral blood samples from 62 cardiac transplant recipients using fluorescent staining and flow cytometry analysis. The results were correlated with histological rejection grade of concurrently taken biopsies, and 5-year survival of the recipients. A decrease in the total T lymphocyte subset, and in CD4+ lymphocytes was associated with higher rejection grade and lesser survival. An increase (5-11%) of double positive CD4+ CD8+ lymphocytes was observed; these were mostly CD4brightCD8dim. The CD4/CD8 ratio was significantly (P < 0.00) lower in the transplant recipients than in normal individuals. CD69 expression was higher than CD54 and CD154 expression on CD4 and CD8 lymphocytes of cardiac transplant recipients; correlation between these activation markers was excellent (P < 0.001). Fluorescent staining for CD69 was often of low intensity. Multiple regression for % CD8+ CD69+ cells and survival, and for % CD69+ T cells and rejection grade yielded a significant correlation (P < 0.050). Both % CD8+ CD69+ and % CD69+ T cells were significantly higher in samples with severe and moderate rejection grade (grades 3A, 3B and 4) than in samples which showed no, minimal or mild rejection (grades < or = 2); P-values were 0.052 and 0.003, respectively. Preliminary results indicated that false negative results could be contributed to increased immunosuppression. We conclude that CD69 expression on circulating CD4 and CD8 lymphocytes is a useful parameter for the diagnosis of moderate and severe rejection.