Histologic features of allograft livers in patients treated for rejection before biopsy.

Liver biopsy is essential for management in liver transplant patients with clinical features suspicious for acute cellular rejection (ACR). As more patients are transplanted for noninfectious indications, it has become increasingly common for them to receive treatment for presumed ACR before biopsy. The effect of pretreatment on the classic histologic triad of ACR's mixed portal inflammation, endothelialitis, and bile duct damage is not well described. Here we report a retrospective study of 70 liver transplant biopsies performed on 53 patients for suspected ACR between 2018 and 2021. Thirty-seven biopsies had a clinical diagnosis of ACR after biopsy. Pretreatment with steroids, antithymocyte globulin, or other increased immunosuppression was given before biopsy in 17 of 37 cases; 20 not-pretreated cases acted as controls. A representative hematoxylin and eosin-stained slide from each biopsy was reviewed independently in a blinded fashion by 3 hepatic pathologists, graded according to the Banff system, assigned a Rejection Activity Index (RAI), and assessed for other histologic features. We found that pretreated biopsies had significantly less portal inflammation (P < .001), less endothelialitis (P < .001), lower RAI (P < .001), and less prominent eosinophils (P = .048) compared to not-pretreated biopsies. There was no significant difference for the other examined variables, including bile duct inflammation/damage (P = .32). Our findings suggest that portal inflammation and endothelialitis become less prominent with pretreatment, whereas bile duct inflammation/damage may take longer to resolve. When evaluating biopsies for suspected ACR, the finding of bile duct inflammation/damage should raise the possibility of partially treated ACR, even in the absence of endothelialitis and portal inflammation.

Histologic mimics and diagnostic pitfalls of gastrointestinal endoscopic lifting media, ORISE™ gel and Eleview®.

Synthetic lifting media, ORISE™ gel and Eleview®, are increasingly used in gastrointestinal endoscopy, but neither comparative features nor pitfalls are well-established. Media histopathology, morphologic mimics, and complications are described, along with helpful stains and endoscopist media preference. A 3-year retrospective search was performed. A total of 123 cases (108 endoscopies and 15 subsequent surgeries) were identified. ORISE gel was used in 86 (79.6%), Eleview in 20 (13.9%), and others in 7 (6.5%). ORISE gel was histologically identified in 58.1% (n = 50) of endoscopic specimens and all 15 resections. Eleview media were not detected histologically. ORISE gel mimicked mucin in hematoxylin and eosin-stained biopsies, concerning for adenocarcinoma misdiagnosis and/or upstaging, but did not stain for mucin. Acid-fast bacterial staining highlights ORISE gel for specific and definitive identification. In resections, ORISE evolves into an amorphous eosinophilic material, often with exuberant giant cell reaction and transmural bowel penetration. Polyp formation leads to polypectomy in one patient, and operative lesions concerning for adenocarcinoma resulted in frozen sections in two patients. ORISE gel mimics mucin, malignant masses, amyloid, pulse granulomata, elastofibromas, and infectious granulomata. No significant endoscopist media preference was identified. Recognition of ORISE gel in tissues eliminates multiple pitfalls. Eleview was not detectable, yielded none of the pitfalls seen with ORISE gel, and, on our survey, has equivalent endoscopist acceptance. In this largest published series to date, Eleview is clearly preferable to ORISE gel.

Pulmonary Eosinophilic Granulomatosis with Polyangiitis Has IgG4 Plasma Cells and Immunoregulatory Features.

The immunologic mechanisms promoting eosinophilic granulomatosis with polyangiitis (EGPA) are unclear. To characterize the mechanisms underlying pulmonary EGPA, we examined and compared EGPA paraffin-embedded lung biopsies with normal lung biopsies, using immunostaining, RNA sequencing, and RT-PCR. The results revealed novel type 2 as well as immuneregulatory features. These features included basophils and increased mast cell contents; increased immunostaining for tumor necrosis factor ligand superfamily member 14; sparse mast cell degranulation; numerous forkhead box protein P3 (FoxP3)+ regulatory T cells and IgG4 plasma cells; and abundant arachidonate 15-lipoxygenase and 25-hydroxyvitamin D-1 α hydroxylase, mitochondrial. Significantly decreased 15-hydroxyprostaglandin dehydrogenase [NAD(+)], which degrades eicosanoids, was observed in EGPA samples. In addition, there was significantly increased mRNA for chemokine (C-C motif) ligands 18 and 13 and major collagen genes, IgG4-rich immune complexes coating alveolar macrophages, and increased immunostaining for phosphorylated mothers against decapentaplegic homolog 2/SMAD2, suggesting transforming growth factor-ß activation. These findings suggest a novel self-promoting mechanism of activation of alveolar macrophages by arachidonate 15-lipoxygenase-derived eicosanoids to express chemokines that recruit a combined type 2/immunoregulatory immune response, which produces these eicosanoids. These results suggest that the pulmonary EGPA immune response resembles the immune response to a tissue-invasive parasite infection.

Prior inpatient admission increases the risk of post-operative infection in hepatobiliary and pancreatic surgery.

BACKGROUND: Hepatobiliary and pancreatic (HPB) operations have a high incidence of post-operative nosocomial infections. The aim of the present study was to determine whether hospitalization up to 1 year before HPB surgery is associated with an increased risk of post-operative infection, surgical-site infection (SSI) and infection resistant to surgical chemoprophylaxis. METHODS: A retrospective cohort study of patients undergoing HPB surgeries between January 2008 and June 2013 was conducted. A multivariable logistic regression model was used for controlling for potential confounders to determine the association between pre-operative admission and post-operative infection. RESULTS: Of the 1384 patients who met eligibility criteria, 127 (9.18%) experienced a post-operative infection. Pre-operative hospitalization was independently associated with an increased risk of a post-operative infection [adjusted odds ratio (aOR): 1.61, 95% confidence interval [CI]: 1.06-2.46] and SSI (aOR: 1.79, 95% CI: 1.07-2.97). Pre-operative hospitalization was also associated with an increased risk of post-operative infections resistant to standard pre-operative antibiotics (OR: 2.64, 95% CI: 1.06-6.59) and an increased risk of resistant SSIs (OR: 3.99, 95% CI: 1.25-12.73). DISCUSSION: Pre-operative hospitalization is associated with an increased incidence of post-operative infections, often with organisms that are resistant to surgical chemoprophylaxis. Patients hospitalized up to 1 year before HPB surgery may benefit from extended spectrum chemoprophylaxis.

Classifying severity of abdominal contour deformities after weight loss to aid in patient counseling: a review of 1006 cases.

BACKGROUND: Abdominal contour deformities after massive weight loss are highly variable, ranging from a mild upper protuberance to multiple rolls. Correction of these deformities is challenging and may require advanced surgical techniques. Evaluating the incidence of patients presenting with various abdominal deformities and the factors influencing these deformities could aid patients undergoing weight loss. METHODS: All massive weight loss patients presenting for abdominal contouring from 2002 to 2012 were reviewed, and abdomens were graded using a modified Pittsburgh Rating Scale. Data collected for each patient included body mass indices, history of bariatric surgery, and type of abdominal contouring surgery. RESULTS: One thousand six patients were evaluated, with a mean age of 44.2 ± 10.5 years. The mean maximum body mass index was 51.7 ± 9.6 kg/m2, mean current body mass index was 30.0 ± 6.4 kg/m2, and mean change in body mass index was 21.7 ± 7.0 kg/m2. Sixty-four percent had a high-grade deformity. Patients with a larger change in body mass index had higher deformity grades (p < 0.001). Patients with higher deformity grades were more likely to undergo a fleur-de-lis abdominoplasty (p < 0.001). CONCLUSIONS: Most patients presenting for body contouring after massive weight loss have high-grade abdominal deformities with multiple rolls. Change in body mass index is positively correlated with deformity grade and more aggressive contouring procedures. Patients interested in massive weight loss should be counseled that, depending on desire for eventual outcomes, more complex procedures may be required to correct the resultant abdominal deformity.