Evaluation of a Zoonotic Orthopoxvirus PCR Assay for the Detection of Mpox Virus Infection.

An epidemic caused by an outbreak of mpox (formerly monkeypox) in May 2022 rapidly spread internationally, requiring an urgent response from the clinical diagnostics community. A detailed description of the clinical validation and implementation of a laboratory-developed real-time PCR test for detecting nonvariola Orthopoxvirus-specific DNA based on the newly designed RealStar Zoonotic Orthopoxvirus assay is presented. The validation was performed using an accuracy panel (n = 97) comprising skin lesion swabs in universal transport media and from mpox virus genomic DNA spiked into pooled mpox virus-negative remnant universal transport media of lesion specimens submitted for routine clinical testing in the NewYork-Presbyterian Hospital clinical laboratory system. Accuracy testing demonstrated excellent assay agreement between expected and observed results and comparable diagnostic performance to three different reference tests. Analytical sensitivity with 95% detection probability was 126 copies/mL, and analytical specificity, clinical sensitivity, and clinical specificity were 100%. In summary, the RealStar Zoonotic Orthopoxvirus assay provides a sensitive and reliable method for routine diagnosis of mpox infections.

PSMA Immunohistochemistry in Hepatic Neoplasms: A Promising Diagnostic Marker With Potential Theranostic Applications.

Accurate classification of well-differentiated hepatocellular neoplasms can be challenging especially in core biopsies. Prostate-specific membrane antigen (PSMA) has been shown to highlight tumor-associated neovasculature in many nonprostatic solid tumors including hepatocellular carcinoma (HCC). Archived 164 hepatectomies and explants with 68 HCCs, 31 hepatocellular adenoma (HA), 24 dysplastic nodules (DN), and 42 metastases were retrieved, and pathologic parameters were evaluated. Sensitivity, specificity, accuracy, positive, and negative predictive values for correct diagnosis of HCC were calculated for PSMA and CD34 immunostains in tissue sections and HCC tissue microarrays. PSMA positivity was defined as capillarized sinusoidal/tumor-associated vessel staining involving ≥5% of the tumor area. In all, 55/68 (80.9%) HCC and 37/42 (88.1%) of liver metastasis were PSMA positive. PSMA was negative in HA, DN, and background liver (100% specificity). CD34 had a 98.5% sensitivity but a 65.5% specificity in identifying HCC. PSMA sensitivity remained high in the HCC tissue microarray (89.7%). PSMA was more accurate than CD34 (95.5% vs. 69.7%) in distinguishing grade 1 HCC from HA and high-grade DN while retaining high sensitivity (80%). The degree of PSMA positivity in HCC was greater in older, male, and human immunodeficiency virus patients ( P <0.05). No associations were found between PSMA staining and other tumor parameters ( P >0.05). PSMA is a marker of neoangiogenesis with increased expression in both primary and metastatic hepatic malignancies. Neovascular PSMA expression is more specific and accurate than CD34 for differentiating HCC from benign and precursor hepatic lesions. Diagnostic and therapeutic utility of PSMA radioligands in malignant liver neoplasms warrant further clinical investigations.

Diversion colitis in inflammatory bowel disease (IBD) is distinct from that in non-IBD: Reappraisal of diversion colitis.

The significant histologic overlap between diversion colitis and inflammatory bowel disease (IBD) poses a diagnostic challenge. We aimed to identify histologic features that are characteristic of diverted colon segments among patients with IBD and compare them with histologic features identified in IBD colectomies. Archived slides from resected diverted colon segments from patients with (n = 79) and without (n = 80) IBD and the corresponding prior colectomies (n = 52) of the IBD patients were reviewed. Clinical and endoscopic data were collected, and a series of histologic features were evaluated and graded. Compared to the non-IBD group, IBD patients were more likely to be symptomatic and present with abnormal endoscopic findings (P < .05). The severity of inflammatory activity, crypt architectural distortion, mucosal atrophy, transmural inflammation, intramucosal lymphoid aggregates (IMLAs), and transmural lymphoid aggregates (TMLAs) were significantly greater in diverted segments in IBD cases than controls (P < .001). The severity of inflammatory activity, IMLAs, TMLAs, and transmural inflammation and the presence of ulcer(s) in the diverted colon segments of IBD patients were associated with the histologic features reflective of IBD activity such as inflammatory activity, transmural inflammation and ulcer(s) in the preceding colectomies (P < .05). Diversion colitis developing in the setting of IBD is endoscopically and histologically distinct from that observed among individuals without IBD. Inflammatory activity, presence of ulcer(s), IMLAs, TMLAs, and transmural inflammation in diverted colon segments of IBD patients may, in part, reflect the severity of underlying IBD rather than pure diversion colitis.

Appendiceal inflammation in colectomy is independently correlated with early pouchitis following ileal pouch anal anastomosis in ulcerative colitis and indeterminate colitis.

BACKGROUND: Appendiceal inflammation in colectomy is one of the histologic predictors of pouchitis in ulcerative colitis (UC) following ileal pouch anal anastomosis (IPAA). Fecal calprotectin level has been shown to increase 2 months prior to the onset of pouchitis. We evaluated whether inflammation and calprotectin expression in appendiceal specimens correlate with early-onset pouchitis in UC and indeterminate colitis (IC). MATERIALS AND METHODS: IPAA (2000-2018) cases with appendix blocks available in colectomy specimens were identified (n = 93, 90 UC, 3 IC). Histologic features thought to predict pouchitis were evaluated. The degree of appendiceal inflammation was scored. Calprotectin immunostain was performed on the appendix blocks and the extent of mucosal staining was quantified. Electronic medical records were reviewed for demographics, smoking history, clinical pouchitis, time of onset of pouchitis, and clinical and endoscopic components of the Pouchitis Disease Activity Index (PDAI) score. Follow-up pouch biopsies were reviewed and scored to generate histologic PDAI score, when available. RESULTS: Among the patients with clinical pouchitis (n = 73), moderate to severe appendiceal inflammation independently correlated with earlier pouchitis compared to no/mild inflammation (median time to pouchitis 12.0 vs. 23.8, log rank p = 0.016). Calprotectin staining correlated with inflammatory scores of the appendix (Spearman's rho, r = 0.630, p < 0.001) but not with early pouchitis (p > 0.05). CONCLUSIONS: The presence of moderate to severe appendiceal inflammation at the time of colectomy was associated with a shorter time to pouchitis following IPAA. Calprotectin immunostain may be used to demonstrate the presence of inflammation in the appendix but its role in predicting early pouchitis remains limited.

Aberrant expression of SATB2, CDX2, CDH17 and CK20 in hepatocellular carcinoma: a pathological, clinical and outcome study.

AIMS: Data regarding expression of intestinal markers in hepatocellular carcinoma (HCC) are limited. We determined the clinicopathological associations of cytokeratin (CK)19, a progenitor liver epithelial cell marker as well as biliary epithelial marker, and intestinal immunohistochemical markers expression in HCC and assessed their prognostic value. METHODS AND RESULTS: Tissue sections and/or tissue microarrays (TMAs) from 202 known HCCs were immunostained using CK19, CK20, CDH17, CDX2 and SATB2 antibodies. Haematoxylin and eosin (H&E)-stained slides were reviewed for tumour grading. Clinical and oncological outcomes were retrieved. Associations of staining with clinicopathological features and survival outcomes were evaluated. CK19, CK20, CDH17, CDX2 and SATB2 were positive in 12.8, 5.4, 10.3, 8.6 and 59.9%, respectively. All but SATB2 were strongly associated with higher tumour grade and AFP levels > 400 ng/ml (P < 0.05). CK19-positive HCC were more likely to express CDX2 (P = 0.001), CDH17 (P < 0.001) and/or CK20 (P = 0.012). CK20, CDX2 and CDH17 co-expression was seen in five cases (2.5%). CK19 and SATB2 positivity, tumour size ≥ 5 cm, background cirrhosis, AFP > 400 ng/ml and having no treatment were associated with decreased overall survival by log-rank test and univariable proportional hazards regression. However, in a multivariable model, CK19 and SATB2 positivity were not independent predictors of decreased survival while their association with known poor prognosticators in HCC was evident. CONCLUSIONS: HCC can express markers of intestinal differentiation. This phenotypical aberrancy correlates with variable clinicopathological parameters, some of which are independent predictors of poor survival.