Increased Frequency of Heterozygous Alpha-1-Antitrypsin Deficiency in Liver Explants From Nonalcoholic Steatohepatitis Patients.

Cirrhotic explanted livers occasionally have unexpected periodic acid-Schiff-diastase (PASD)-positive globules within the hepatocyte cytoplasm. It is often unclear whether this finding is a nonspecific consequence of cirrhosis or is indicative of an underlying alpha-1-antitrypsin deficiency (A1ATD) contributing to the cirrhosis. In this study, explanted livers were retrospectively evaluated for histopathology (including PASD status with confirmatory alpha-1-antitrypsin [A1AT] immunohistochemistry [IHC]), and chart review provided etiology of liver failure and general clinical parameters. Real-time polymerase chain reaction was used to detect A1AT genotype (SERPINA1 S and Z alleles) by melting curve analysis on liver explant tissue from selected cases. Of 196 explanted livers, 21 (11%) had PASD+ globules, which were significantly enriched in patients with a clinical diagnosis of nonalcoholic steatohepatitis (NASH; 47%) compared with other causes (P < 0.001). IHC confirmed all PASD+ globules were A1AT+, with 20 of 21 cases demonstrating diffuse A1AT staining. In an expanded NASH cohort, 42% (14/33) of explants had PASD+ globules, 92% of which were homozygous (n = 1) or heterozygous (n = 11) for the SERPINA1 Z allele, corresponding to nearly 40% of all NASH patients. Overall, the Z allele was present in 10% of all tested liver explants, with 85% of PASD+ cases genotyping homozygous (n = 2) or heterozygous (n = 20), which is far in excess of the estimated 2% in the general population. These results indicate PASD+ A1AT globules (with confirmatory genotyping showing at least 1 Z allele) are commonly observed in NASH, suggesting a synergistic relationship toward liver fibrosis. In addition, the high frequency of SERPINA1 Z alleles in liver transplantation patients supports the utility of pretransplant genotyping.

Investigation of anal motor characteristics of the sensorimotor response (SMR) using 3-D anorectal pressure topography.

Desire to defecate is associated with a unique anal contractile response, the sensorimotor response (SMR). However, the precise muscle(s) involved is not known. We aimed to examine the role of external and internal anal sphincter and the puborectalis muscle in the genesis of SMR. Anorectal 3-D pressure topography was performed in 10 healthy subjects during graded rectal balloon distention using a novel high-definition manometry system consisting of a probe with 256 pressure sensors arranged circumferentially. The anal pressure changes before, during, and after the onset of SMR were measured at every millimeter along the length of anal canal and in 3-D by dividing the anal canal into 4 × 2.1-mm grids. Pressures were assessed in the longitudinal and anterior-posterior axis. Anal ultrasound was performed to assess puborectalis morphology. 3-D topography demonstrated that rectal distention produced an SMR coinciding with desire to defecate and predominantly induced by contraction of puborectalis. Anal ultrasound showed that the puborectalis was located at mean distance of 3.5 cm from anal verge, which corresponded with peak pressure difference between the anterior and posterior vectors observed at 3.4 cm with 3-D topography (r = 0.77). The highest absolute and percentage increases in pressure during SMR were seen in the superior-posterior portion of anal canal, reaffirming the role of puborectalis. The SMR anal pressure profile showed a peak pressure at 1.6 cm from anal verge in the anterior and posterior vectors and distinct increase in pressure only posteriorly at 3.2 cm corresponding to puborectalis. We concluded that SMR is primarily induced by the activation and contraction of the puborectalis muscle in response to a sensation of a desire to defecate.

Real-Time PCR to Detect α-1 Antitrypsin S and Z Alleles in Formalin-Fixed Paraffin-Embedded Tissue.

BACKGROUND: α-1 Antitrypsin (A1AT) deficiency is an autosomal recessive genetic disease with incomplete penetrance that can cause pulmonary and liver disease. Multiple methods are available to determine A1AT genotype using peripheral blood specimens, but none are validated to detect A1AT alleles in formalin-fixed paraffin-embedded (FFPE) tissue. METHODS: A real-time PCR assay was validated to detect the SERPINA1 S and Z alleles (NM_000295.4: c.863A>T, p.E288V and c.1096G>A, p.E366K, respectively) in FFPE liver tissue using allele-specific dual hybridization probes and melting curve analysis. Validation experiments were performed on genomic DNA samples (n = 11) with A1AT genotypes previously determined by orthogonal methods. RESULTS: The S and Z allele assays accurately genotyped all FFPE validation specimens that had a threshold cycle <32. Validation samples produced mean melting temperatures of 55.4 °C (SD = 0.30) for mutant S alleles, 48.6 °C (SD = 0.28) for non-S alleles, 61.2 °C (SD = 0.34) for mutant Z alleles, and 54.7 °C (SD = 0.19) for non-Z alleles. Samples failing to meet quality control parameters were infrequent. CONCLUSIONS: Poor PCR amplification because of low nucleic acid concentration in small biopsy specimens and time-dependent degradation in specimens stored for extended periods were the most common reasons for assay failure. The ability to determine A1AT genotype from archived surgical pathology specimens can facilitate research on the role of A1AT globules in liver disease.

Radiologically Undetected Hepatocellular Carcinoma in Patients Undergoing Liver Transplantation: An Immunohistochemical Correlation With LI-RADS Score.

Orthotopic liver transplantation is the best option for patients with carefully selected unresectable disease because of underlying liver dysfunction. The 5-year survival rate after orthotopic liver transplantation for early detected hepatocellular carcinoma (HCC) is high, and a similar or even higher rate is reported in those with radiologically undetected HCC. This study evaluated and compared the histologic features of pretransplant radiologically undetected (14 patients, 25 tumors) versus detected (36 patients, 45 tumors) HCCs. Tumor size, tumor differentiation, number of unpaired arteries, mitotic count per 10 high-power fields, CD34 immunostain to assess microvessel density, and Ki67 immunostain were compared with the Liver Imaging Reporting and Data System score, which was retrospectively assigned to each tumor in both groups. The Liver Imaging Reporting and Data System score was significantly higher in the HCC detected group (P<0.001). The vast majority of the undetected HCCs (88%) was <2 cm in size. Only 12% of the undetected HCCs were ≥2 cm, whereas 51% of the detected HCCs were ≥2 cm in size. Higher rate of moderate to poor tumor differentiation was noted in the detected HCCs compared with the undetected group (89% vs. 60%; P=0.004). No statistically significant difference in the number and distribution of unpaired arteries, or mitotic count was observed in 2 groups (although fewer unpaired arteries were identified in the undetected group). The detected HCCs had a higher rate of 2+ CD34 staining compared with the undetected HCCs (68% vs. 27%; P=0.002), whereas the opposite was observed for 1+ CD34 staining (59% undetected HCCs vs. 17% detected HCCs; P=0.002). Ki67 proliferative index was not statistically different between the 2 groups (120.8/1000 cells detected HCCs vs. 81.8/1000 cells undetected HCCs; P=0.36). The factors associated with failing to detect HCCs pretransplant by radiologic studies include small tumor size (<2 cm), low-grade histologic differentiation, and low microvessel density (low CD34 staining). A significant association between the number and distribution of unpaired arteries and HCC detection has not been established by our study.