Tomas Slavik

Activated intestinal macrophages in patients with cirrhosis release NO and IL- 6 that may disrupt intestinal barrier function

BACKGROUND & AIMS Bacterial infections commonly occur in decompensated cirrhosis resulting from bacterial translocation from the intestine. We studied the role of intestinal macrophages and the epithelial barrier in cirrhosis. METHODS Forty-four patients with NASH/ASH cirrhosis (decompensated n=29, compensated n=15) and nineteen controls undergoing endoscopy were recruited. Serum was obtained and LPS and LBP levels determined. Intestinal macrophages were characterized by flow cytometry, immunohistochemistry, and nitric oxide (NO) production measured in supernatant of cultured duodenal samples. Quantitative RT-PCR was performed on duodenal biopsies assessing 84 inflammatory genes. Protein levels of cytokines/chemokines were assessed in serum and supernatant. The duodenal wall was assessed by electron microscopy, tight junction protein expression determined by RT-PCR, immunohistochemistry, and Western blot and, functional analysis performed by transepithelial resistance measurement and permeability studies. RESULTS Increased plasma LPS, LBP levels and higher numbers of duodenal CD33(+)/CD14(+)/Trem-1(+) macrophages, synthesizing iNOS and secreting NO were present in decompensated cirrhosis. Upregulation of IL-8, CCL2, CCL13 at the transcriptional level, and increased IL-8, and IL-6 were detected in supernatant and serum in cirrhosis. IL-6 and IL-8 co-localised with iNOS(+) and CD68(+), but not with CD11c(+) cells. Electron microscopy demonstrated an intact epithelial barrier. Increased Claudin-2 was detected by Western blot and immunohistochemistry, while decreased transepithelial resistance and increased duodenal permeability were detected in decompensated cirrhosis. CONCLUSIONS Our study shows the presence of activated CD14(+)Trem-1(+)iNOS(+) intestinal macrophages, releasing IL-6, NO, and increased intestinal permeability in patients with cirrhosis, suggesting that these cells may produce factors capable of enhancing permeability to bacterial products.

Absence of Helicobacter pylori within the Oral Cavities of Members of a Healthy South African Community

ABSTRACT Our study aimed to evaluate the oral cavity as a reservoir from where Helicobacter pylori may be transmitted. Histology and PCR amplification were performed. Eighty-four percent of the stomach biopsies tested positive; however, H. pylori was not detected in dental samples, indicating the absence of H. pylori within the oral cavity.

Incidence of Helicobacter felis and the Effect of Coinfection with Helicobacter pylori on the Gastric Mucosa in the African Population

ABSTRACT Helicobacter pylori and Helicobacter felis are two of the Helicobacter spp. that infect humans. H. pylori has been linked to significant gastric pathology. Coinfection with Helicobacter spp. may influence infectious burden, pathogenesis, and antibiotic resistance; however, this has not been studied. The aims of this study were to identify the incidence of H. felis and to analyze the effects of coinfection with both organisms on gastric pathology in a well-characterized South African population. Biopsy samples from the gastric corpora and antra of volunteers (n = 90) were subjected to histological examination and PCR for the identification of H. pylori and H. felis. We further investigated the effect of global strain type on the occurrence of precursor lesions by assigning nucleotide sequences derived from PCR amplification of three genes to global groupings (ancestral Africa1, ancestral Africa2, ancestral Europe, ancestral Asia, and mixed). H. pylori was detected in 75 (83.3%), H. felis in 23 (25.6%), and coinfection in 21 (23.3%) of the volunteers by PCR. H. felis was randomly distributed among adults and children but clustered within families, suggesting intrafamilial transmission. Analysis of histopathology scores revealed no differences in atrophy, activity, and helicobacter density between H. felis-positive and H. felis-negative volunteers. H. pylori substrains common to southern Africa showed no differences in inflammation or atrophy scores. The incidences of H. felis and coinfection with H. pylori in the African population are high. H. felis infection, however, does not influence specific gastric pathology in this population.

Cronkhite–Canada syndrome six decades on: the many faces of an enigmatic disease

Cronkhite–Canada syndrome is a rare gastro-entero-colopathy of uncertain aetiology first described almost 60 years ago. It is characterised by diffuse gastrointestinal polyposis sparing only the oesophagus, ectodermal abnormalities and an unpredictable but often fatal clinical course. The disease may demonstrate extremely diverse clinical and endoscopic features, which often leads to a delay in diagnosis. A high index of suspicion and recognition of the characteristic histological findings frequently facilitate a correct diagnosis, but the distribution of the gastrointestinal pathology and its microscopic features may be atypical. The pathologist thus requires a thorough knowledge of both the typical and many atypical faces of this disease, for which various documented therapies often still prove ineffective. Close correlation with clinical findings, including any pertinent ectodermal abnormalities, and careful examination of biopsies derived from polypoid and endoscopically spared mucosa will ensure a timely and correct diagnosis in patients with this enigmatic syndrome.

Impaired CD4+ T-Cell Restoration in the Small Versus Large Intestine of HIV-1–Positive South Africans Receiving Combination Antiretroviral Therapy

BACKGROUND Human immunodeficiency virus type 1 (HIV-1) infection is associated with a massive depletion of intestinal CD4(+) T cells that is only partially reversed by combination antiretroviral therapy (cART). Here, we assessed the ability of nucleoside reverse-transcriptase inhibitor/nonnucleoside reverse-transcriptase inhibitor treatment to restore the CD4(+) T-cell populations in the intestine of South African patients with AIDS. METHODS Thirty-eight patients with advanced HIV-1 infection who had chronic diarrhea (duration, >4 weeks) and/or unintentional weight loss (>10% decrease from baseline) of uncertain etiology were enrolled. Blood specimens were collected monthly, and gastrointestinal tract biopsy specimens were collected before cART initiation (from the duodenum, jejunum, ileum, and colon), 3 months after cART initiation (from the duodenum), and 6 months after cART initiation (from the duodenum and colon). CD4(+), CD8(+), and CD38(+)CD8(+) T cells were quantified by flow cytometry and immunohistochemistry analyses, and the HIV-1 RNA load was determined by the Nuclisens assay. RESULTS CD4(+) T-cell and HIV-1 RNA levels were significantly lower, whereas CD8(+) T-cell levels, including activated CD38(+)CD8(+) T cell levels, were higher in the duodenum and jejunum, compared with the colon. After 6 months of cART, a significant but incomplete recovery of CD4(+) T cells was detected in the colon and peripheral blood but not in the duodenum. Failed restoration of the CD4(+) T-cell count in the duodenum was associated with nonspecific enteritis and CD8(+) T-cell activation. CONCLUSIONS Strategies that target inflammation and immune activation in the small intestine may be required to expedite CD4(+) T-cell recovery and improve therapeutic outcomes.

CD14 + macrophages that accumulate in the colon of African AIDS patients express pro-inflammatory cytokines and are responsive to lipopolysaccharide

BackgroundIntestinal macrophages are key regulators of inflammatory responses to the gut microbiome and play a central role in maintaining tissue homeostasis and epithelial integrity. However, little is known about the role of these cells in HIV infection, a disease fuelled by intestinal inflammation, a loss of epithelial barrier function and increased microbial translocation (MT).MethodsPhenotypic and functional characterization of intestinal macrophages was performed for 23 African AIDS patients with chronic diarrhea and/or weight loss and 11 HIV-negative Africans with and without inflammatory bowel disease (IBD). AIDS patients were treated with cotrimoxazole for the prevention of opportunistic infections (OIs). Macrophage phenotype was assessed by flow cytometry and immuno-histochemistry (IHC); production of proinflammatory mediators by IHC and Qiagen PCR Arrays; in vitro secretion of cytokines by the Bio-Plex Suspension Array System. Statistical analyses were performed using Spearman’s correlation and Wilcoxon matched-pair tests. Results between groups were analyzed using the Kruskal-Wallis with Dunn’s post-test and the Mann–Whitney U tests.ResultsNone of the study participants had evidence of enteric co-infections as assessed by stool analysis and histology. Compared to healthy HIV-negative controls, the colon of AIDS patients was highly inflamed with increased infiltration of inflammatory cells and increased mRNA expression of proinflammatory cytokine (tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IFN-γ, and IL-18), chemokines (chemokine (C-C motif) ligand (CCL)2 and chemokine (C-X-C) motif ligand (CXCL)10) and transcription factors (TNF receptor-associated factor (TRAF)6 and T-box (TXB)21). IHC revealed significant co-localization of TNF-α and IL-1β with CD68+ cells. As in IBD, HIV was associated with a marked increase in macrophages expressing innate response receptors including CD14, the co-receptor for lipopolysaccharide (LPS). The frequency of CD14+ macrophages correlated positively with plasma LPS, a marker of MT. Total unfractionated mucosal mononuclear cells (MMC) isolated from the colon of AIDS patients, but not MMC depleted of CD14+ cells, secreted increased levels of proinflammatory cytokines ex vivo in response to LPS.ConclusionsIntestinal macrophages, in the absence of overt OIs, play an important role in driving persistent inflammation in HIV patients with late-stage disease and diarrhea. These results suggest intensified treatment strategies that target inflammatory processes in intestinal macrophages may be highly beneficial in restoring the epithelial barrier and limiting MT in HIV-infected patients.

Diagnosis and Predictive Molecular Analysis of Non–Small-Cell Lung Cancer in the Africa-Middle East Region: Challenges and Strategies for Improvement

The identification of tumor biomarkers provides information on the prognosis and guides the implementation of appropriate treatment in patients with many different cancer types. In non-small cell lung cancer (NSCLC), targeted treatment plans based on biomarker identification have already been used in the clinic. However, such predictive molecular testing is not currently a universally used practice. This is the case, in particular, in developing countries where lung cancer is increasingly prevalent. In September 2012 and November 2013, a committee of 16 lung cancer experts from Africa and the Middle East met to discuss key issues related to diagnosis and biomarker testing in NSCLC and the implementation of personalized medicine in the region. The committee identified current challenges for effective diagnosis and predictive analysis in Africa and the Middle East. Moreover, strategies to encourage the implementation of biomarker testing were discussed. A practical approach for the effective diagnosis and predictive molecular testing of NSCLC in these regions was derived. We present the key issues and recommendations arising from the meetings.

Toothy craniopharyngioma: a literature review and case report of craniopharyngioma with extensive odontogenic differentiation and tooth formation

A young child presenting with a craniopharyngioma (pituitary adamantinoma) demonstrated the rare phenomenon of pronounced odontogenic elements/tooth formation on imaging. The origin of the craniopharyngioma from primitive stomatodeum theoretically facilitates odontogenesis [1]. Theories of the genesis of this tumour include remnants of the craniopharyngeal duct, squamous metaplasia of anterior pituitary cells and misplaced tissue of the embryonic enamel organ [2]. A literature review documents six cases of craniopharyngioma with tooth formation although none appear to be as extensive as the case presented. Craniopharyngioma should be added to teratoma in the differential diagnosis of suprasellar odontogenic elements demonstrated by imaging studies.

POLYMERASE CHAIN REACTION AMPLIFYING MYCOBACTERIAL DNA FROM ASPIRATES OBTAINED BY ENDOSCOPIC ULTRASOUND ALLOWS ACCURATE DIAGNOSIS OF MYCOBACTERIAL DISEASE IN HIV-POSITIVE PATIENTS WITH ABDOMINAL LYMPHADENOPATHY

Abdominal lymphadenopathy in human immunodeficiency virus (HIV) infection remains a diagnostic challenge. We performed a prospective cohort study by recruiting 31 symptomatic HIV + patients with abdominal lymphadenopathy and assessing the diagnostic yield of endoscopic ultrasound fine-needle aspiration (EUS-FNA). Mean age was 38 years; 52% were female; and mean CD4 count and viral load were 124 cells/μL and 4 log, respectively. EUS confirmed additional mediastinal nodes in 26%. The porta hepatis was the most common abdominal site. Aspirates obtained by EUS-FNA were subjected to cytology, culture and polymerase chain reaction (PCR) analysis. Mycobacterial infections were confirmed in 67.7%, and 31% had reactive lymphadenopathy. Cytology and culture had low sensitivity, whereas PCR identified 90% of mycobacterial infections. By combining the appearance of aspirates obtained by EUS-FNA and cytologic specimens, we developed a diagnostic algorithm to indicate when analysis with PCR would be useful. PCR performed on material obtained by EUS-FNA was highly accurate in confirming mycobacterial disease and determining genotypic drug resistance.

Plasmablastic lymphoma versus diffuse large B cell lymphoma with plasmablastic differentiation: proposal for a novel diagnostic scoring system

High-grade non-Hodgkin’s lymphomas with plasmablastic differentiation are frequently encountered in HIV-positive patients. Differentiating between diffuse large B cell lymphoma (DLBCL) with plasmablastic differentiation and true cases of plasmablastic lymphoma (PBL) is sometimes challenging, particularly as a substantial overlap in immunphenotype exists between late-stage B cell neoplasms and PBL. This study sought to develop an immunohistochemical panel to more reliably distinguishing between PBL and DLBCL with plasmablastic differentiation. Thirty-nine CD20-negative, ALK-negative, HHV8-negative non-Hodgkin’s lymphomas with plasmablastic differentiation defined by their morphological features, high proliferation index and positivity for MUM1/IRF4 and PRDM/Blimp1 protein expression were compared regarding their protein expression profiles, viral status and c-MYC-gene aberrations. These lymphomas were subsequently divided in two groups utilising CD10 and Pax5. Tumours without reactivity for either of these markers exhibited higher expression of CD138 and CD117 frequently used as the plasma cell (PC) markers, whilst tumours with reactivity for one or both markers showed a significantly higher expression of CD38 and MYC-gene aberrations. A novel diagnostic scoring system which includes the immunohistochemical expression of CD10 and Pax5 is proposed to differentiate between DLBCL with plasmablastic differentiation and true cases of PBL.