The diagnosis of clinically significant oesophageal Candida infections: a reappraisal of clinicopathological findings.

AIMS: Distinguishing true oesophageal Candida infections from oral contaminants is a common diagnostic issue. Historically, histological features believed to indicate true infection included epithelial invasion by pseudohyphae and intraepithelial neutrophils. Whether or not these features correlate with endoscopic lesions, symptoms and response to therapy has never been tested in a large cohort. The aim of this study was to determine whether specific histological features correlate with clinical and endoscopic findings when Candida is found in oesophageal biopsies. METHODS AND RESULTS: We reviewed 271 biopsies in which Candida was detected. Cases were evaluated for the presence of desquamated epithelial cells, location/type of fungal forms, neutrophils, and ulceration. Medical records were reviewed for clinical history, endoscopic lesions, and response to antifungal therapy. Statistical analysis was used to determine whether any histological features significantly correlated with clinical variables. There were 120 males and 151 females with a mean age of 42 years. Fifty-nine per cent had symptoms referable to the oesophagus, particularly dysphagia (36%). Most (73%) patients had abnormal endoscopic findings, with plaques, ulcers, or macroscopic evidence of oesophagitis. Seventy-one per cent of patients with documented antifungal therapy showed symptomatic improvement. Overall, there was no statistically significant correlation between any histological feature and presenting symptoms, endoscopic findings, or response to therapy. Importantly, the lack of pseudohyphae, demonstrable invasion of intact epithelium or neutrophilic infiltrates did not exclude clinically significant infection. CONCLUSIONS: We conclude that detection of Candida in oesophageal biopsies is always potentially clinically significant. Treatment decisions should be made on the basis of an integration of clinical, endoscopic and histological findings.

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

BACKGROUND: Intestinal 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). METHODS: Phenotypic 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. RESULTS: None 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)-1ß, 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-1ß 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. CONCLUSIONS: Intestinal 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.

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.

Esophageal lymphocytosis: exploring the knowns and unknowns of this pattern of esophageal injury.

INTRODUCTION: Lymphocyte-rich inflammation of the esophageal mucosa has gained increased awareness among pathologists and clinicians recently. Patients usually present with symptoms of esophageal dysfunction, including dysphagia and food bolus impaction. Endoscopy may show changes similar to eosinophilic esophagitis but may also be entirely normal ('microscopic esophagitis'). Three morphological subtypes or variant forms have been described which include lymphocytic, lichenoid and lymphocyte-predominant esophagitis. These need to be discriminated against other distinct causes of esophageal lymphocytosis, such as gastro-esophageal reflux disease and Candida infection. AREAS COVERED: This review provides an overview of diagnostic criteria and clinical associations of the disorder and presents an algorithmic approach to diagnosis. A comprehensive literature review was conducted using PubMed, Medline and Google Scholar databases to identify articles related to lymphocyte-rich esophageal inflammation, published up to March 2024. EXPERT OPINION: Lymphocyte-rich inflammation needs to be included in the differential diagnosis and clinical work-up of patients with esophageal dysfunction. There is currently considerable morphological overlap among published subtypes or variant forms. Follow-up studies of affected individuals are needed to formalize diagnostic parameters and identify the clinical course of disease in order to optimize treatment modalities.

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.

Subtyping intestinal metaplasia in patients with chronic atrophic gastritis: an interobserver variability study.

Incomplete gastric intestinal metaplasia (GIM) is associated with an increased risk of gastric cancer. We aimed to examine the interobserver variability of GIM subtyping (incomplete vs complete) in histological diagnosis of patients with chronic atrophic gastritis and to identify factors with potential impact on agreement. Nine international gastrointestinal expert pathologists assessed 46 cases with complete, incomplete or mixed-type GIM on scanned haematoxylin and eosin (H&E)-stained slides. Results were compared with the consensus diagnosis driven by two experts. Interobserver variability was evaluated by kappa statistics. Focusing on the predominant pattern, the agreement between each observer and the consensus diagnosis ranged from 78% to 98%. The level of agreement was moderate to almost perfect (weighted kappa=0.464-0.984). The participating pathologists reached substantial overall agreement (Fleiss' kappa=0.716, 95% confidence interval 0.677-0.755). Misclassification with potential impact on clinical decision making occurred in 5.7% of case ratings. The pattern of GIM (pure GIM versus mixed-type GIM) differed significantly between cases with high and low agreement (p=0.010), while the number of biopsy pieces per sample and the portion of mucosal surface involved by GIM did not. Pathologists who apply subtyping in daily routine performed better than those who do not (p=0.040). In conclusion, subtyping GIM on H&E-stained slides can be achieved satisfactorily with high interobserver agreement. The implementation of GIM subtyping as a risk stratifying tool in current practice guidelines by the European Society of Gastrointestinal Endoscopy (ESGE) and the American Gastroenterological Association (AGA) carries a low rate of misclassification, at least among gastrointestinal expert pathologists.

Interobserver agreement of estimating the extent of intestinal metaplasia in patients with chronic atrophic gastritis.

The extent of gastric intestinal metaplasia (GIM) can be used to determine the risk of gastric cancer. Eleven international gastrointestinal expert pathologists estimated the extent of GIM on haematoxylin and eosin (H&E)- and Alcian blue-Periodic acid Schiff (AB-PAS)-stained slides of 46 antrum biopsies in 5% increments. Interobserver agreement was tested with the intraclass correlation coefficient (ICC). Correlation between standard deviation and extent of GIM was evaluated with the Spearman correlation. The interobserver agreement was very good (ICC = 0.983, 95% confidence interval (CI) 0.975-0.990). The use of AB-PAS did not increase the agreement (ICC = 0.975, 95% CI 0.961-0.985). Cases with a higher amount of metaplastic epithelium demonstrated a higher standard deviation (rs = 0.644; p < 0.01), suggesting lower diagnostic accuracy in cases with extensive GIM. In conclusion, estimating the extent of GIM on H&E-stained slides in patients with chronic atrophic gastritis can be achieved satisfactorily with high interobserver agreement, at least among international expert gastrointestinal pathologists.

A de novo 2.2 Mb recurrent 17q23.1q23.2 deletion unmasks novel putative regulatory non-coding SNVs associated with lethal lung hypoplasia and pulmonary hypertension: a case report.

BACKGROUND: Application of whole genome sequencing (WGS) enables identification of non-coding variants that play a phenotype-modifying role and are undetectable by exome sequencing. Recently, non-coding regulatory single nucleotide variants (SNVs) have been reported in patients with lethal lung developmental disorders (LLDDs) or congenital scoliosis with recurrent copy-number variant (CNV) deletions at 17q23.1q23.2 or 16p11.2, respectively. CASE PRESENTATION: Here, we report a deceased newborn with pulmonary hypertension and pulmonary interstitial emphysema with features suggestive of pulmonary hypoplasia, resulting in respiratory failure and neonatal death soon after birth. Using the array comparative genomic hybridization and WGS, two heterozygous recurrent CNV deletions: ~ 2.2 Mb on 17q23.1q23.2, involving TBX4, and ~ 600 kb on 16p11.2, involving TBX6, that both arose de novo on maternal chromosomes were identified. In the predicted lung-specific enhancer upstream to TBX4, we have detected seven novel putative regulatory non-coding SNVs that were absent in 13 control individuals with the overlapping deletions but without any structural lung anomalies. CONCLUSIONS: Our findings further support a recently reported model of complex compound inheritance of LLDD in which both non-coding and coding heterozygous TBX4 variants contribute to the lung phenotype. In addition, this is the first report of a patient with combined de novo heterozygous recurrent 17q23.1q23.2 and 16p11.2 CNV deletions.

An unusual case of abdominal mycobacterial infection: Case report and literature review.

This article presents a case of an HIV-infected paediatric patient with an unusual Mycobacterium genavense infection with predominantly abdominal organ involvement.

Thymoma-associated multiorgan autoimmunity with exclusive gastrointestinal tract involvement: case report and review of the literature.

Thymoma-associated multiorgan autoimmunity (TAMA) is a recently delineated and rare paraneoplastic syndrome reported in patients with thymoma. The disorder is characterized by graft-versus-host disease-like pathology affecting the skin, gastrointestinal tract (GIT), and liver, and is usually associated with a poor outcome. We document a case of TAMA with exclusive GIT involvement which included the stomach, small and large bowel, presenting in a 66-year-old male patient 5 years after complete resection of a type B2 thymoma. A brief review is provided of this scarce syndrome, the GIT pathology described in the 21 TAMA cases reported to date, and the unique characteristics of patients with exclusive GIT involvement by this acquired autoimmune disorder.

Navigating the jungles of tropical infectious gastrointestinal pathology: a pattern-based approach to the endoscopic biopsy.

International travels and global human migration have had the unforeseen consequence of increasing the exposure of histopathologists in developed countries to the pathology of tropical infectious disease. The gastrointestinal tract (GIT) is often the primary site of infection due to the faecal-oral route of transmission and the high risk of exposure to contaminated water, food or soil when travelling to these regions. Whilst current microbiologic techniques are far more sensitive than histology in detecting infectious pathogens, the histopathologist nonetheless retains a pivotal role in diagnosing tropical GIT disease. This role entails evaluating endoscopic biopsies for any characteristic inflammatory pattern, identifying pathogens which may be present and excluding other look-alike pathologies. Recent advances in commercially available diagnostic modalities, including molecular techniques, have further broadened the scope of the histopathologist's armamentarium. This review outlines a practical pattern-based approach to diagnosing tropical GIT infections in endoscopic material, so as to assist pathologists less familiar with this spectrum of pathology.

Uterine PEComas: A Morphologic, Immunohistochemical, and Molecular Analysis of 32 Tumors.

Uterine perivascular epithelioid cell tumors (PEComas) are rare neoplasms that may show overlapping morphology and immunohistochemistry with uterine smooth muscle tumors. In this study, we evaluated the morphologic, immunohistochemical, and molecular features of 32 PEComas, including 11 with aggressive behavior. Two distinct morphologies were observed: classic (n=30) and those with a lymphangioleiomyomatosis appearance (n=2). In the former, patients ranged from 32 to 77 (mean: 51) years and 13% had tuberous sclerosis. Tumors ranged from 0.2 to 17 (mean: 5.5) cm with 77% arising in the corpus. Epithelioid cells were present in 100% and a spindled component was seen in 37%. Nuclear atypia was low (53%), intermediate (17%), or high (30%). Mitoses ranged from 0 to 36 (mean: 6) and 0 to 133 (mean: 19) per 10 and 50 high-power fields, with atypical mitoses present in 30%. Thin and delicate vessels were noted in 100%, clear/eosinophilic and granular cytoplasm in 93%, stromal hyalinization in 73%, necrosis in 30%, and lymphovascular invasion in 10%. All tumors were positive for HMB-45, cathepsin K, and at least one muscle marker, with most expressing melan-A (77%) and/or MiTF (79%). A PSF-TFE3 fusion was identified in one while another showed a RAD51B-OPHN1 fusion. Follow-up ranged from 2 to 175 (mean: 41) months, with 63% of patients alive and well, 20% dead of disease, 13% alive with disease, and 3% dead from other causes. In the latter group (n=2), patients were 39 and 49 years old, one had tuberous sclerosis, while the other had pulmonary lymphangioleiomyomatosis. Both tumors expressed HMB-45, cathepsin K, and muscle markers, but lacked TFE3 and RAD51B rearrangements. The 2 patients are currently alive and well. Application of gynecologic-specific criteria (≥4 features required for malignancy: size ≥5 cm, high-grade atypia, mitoses >1/50 high-power fields, necrosis, and lymphovascular invasion) for predicting outcome misclassified 36% (4/11) of aggressive tumors; thus, a modified algorithm with a threshold of 3 of these features is recommended to classify a PEComa as malignant.

Effect of rapamycin on hepatic osteodystrophy in rats with portasystemic shunting.

AIM: To study if T-cell activation related to portasystemic shunting causes osteoclast-mediated bone loss through RANKL-dependent pathways. We also investigated if T-cell inhibition using rapamycin would protect against bone loss in rats. METHODS: Portasystemic shunting was performed in male Sprague-Dawley rats and rapamycin 0.1 mg/kg was administered for 15 wk by gavage. Rats received powderized chow and supplemental feeds to prevent the effects of malnutrition on bone composition. Weight gain and growth was restored after surgery in shunted animals. At termination, biochemical parameters of bone turnover and quantitative bone histology were assessed. Markers of T-cell activation, inflammatory cytokine production, and RANKL-dependent pathways were measured. In addition, the roles of IGF-1 and hypogonadism were investigated. RESULTS: Portasystemic shunting caused low turnover osteoporosis that was RANKL independent. Bone resorbing cytokine levels, including IL-1, IL-6 and TNFalpha, were not increased in serum and TNFalpha and RANKL expression were not upregulated in PBMC. Portasystemic shunting increased the circulating CD8+ T-cell population. Rapamycin decreased the circulating CD8+ T-cell population, increased CD8+ CD25+ T-regulatory cell population and improved all parameters of bone turnover. CONCLUSION: Osteoporosis caused by portasystemic shunting may be partially ameliorated by rapamycin in the rat model of hepatic osteodystrophy.

Cronkhite­Canada syndrome six decades on: the many faces of an enigmatic disease.

Cronkhite­Canada syndrome is a rare gastro-enterocolopathy 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.

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.

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.

Human immunodeficiency virus-related gastrointestinal pathology: a southern Africa perspective with review of the literature (part 1: infections).

CONTEXT: Human immunodeficiency virus infection is rife in sub-Saharan Africa and in southern Africa in particular. Despite the increasing availability of antiretroviral therapy in this region, opportunistic infections remain common and frequently involve the gastrointestinal tract. OBJECTIVE: To review the histopathologic findings and distinguishing features of human immunodeficiency virus-associated gastrointestinal infections in southern Africa and relate those findings to the documented international literature. DATA SOURCES: The available literature on this topic was reviewed and supplemented with personal experience in a private histopathology practice in South Africa. CONCLUSIONS: In southern Africa, the range of gastrointestinal, opportunistic infectious pathology in human immunodeficiency virus afflicted patients is diverse and includes viral, bacterial, fungal, and parasitic infections. This infectious pathology is sometimes a manifestation of systemic disease. In profoundly immunocompromised patients, unusual histologic features, involvement of uncommon gastrointestinal tract sites, and more than one pathogen may be seen.

Human immunodeficiency virus-related gastrointestinal pathology: a southern Africa perspective with review of the literature (part 2: neoplasms and noninfectious disorders).

CONTEXT: Human immunodeficiency virus (HIV) infection is rife in sub-Saharan Africa and in southern Africa in particular. Despite the increasing availability of antiretroviral therapy in this region, HIV-associated neoplasms remain common and frequently involve the gastrointestinal tract, which may also demonstrate other noninfectious, HIV-related pathology. OBJECTIVE: To review the histopathologic findings and distinguishing features of neoplastic and noninfectious, HIV-associated gastrointestinal disorders in southern Africa and relate those findings to the documented international literature. DATA SOURCES: The available literature on this topic was reviewed and supplemented with personal experience in a private histopathology practice in South Africa. CONCLUSIONS: In southern Africa, a diverse range of HIV-related neoplasms and noninfectious gastrointestinal disorders is seen, but published data for the region are scarce. The gastrointestinal disorders include drug-associated pathology, gastrointestinal manifestations of the immune reconstitution inflammatory syndrome, idiopathic chronic esophageal ulceration, and the controversial entity of HIV enteropathy.