[Cytomegalovirus hepatitis diagnosis optimization in liver transplant recipients: 10 years of experience]

BACKGROUND

Cytomegalovirus (CMV) hepatitis constitutes a challenging diagnostic entity in liver transplant (LT) recipients.

AIM

To determine the real incidence of CMV hepatitis using more specific diagnostic tools as those currently used before.

METHODS

Retrospective/prospective study conducted in a hepatic transplant unit from 2009 to 2019. LT recipients with CMV specific or suggestive elements in histopathology of hepatic biopsies were included. Immunohistochemistry (IHQ) was performed in tissue samples of the studied cohort as well as in a control one.

RESULTS

41 patients met the inclusion criteria. IHQ was diagnostic in 6 (14.6%), and was negative in 100% of the control population. The negative predictive value of the histopathology for CMV hepatitis diagnosis was 100% and the positive predictive value was 14.6%. 85% of patients in whom the IHQ was negative had alternative diagnosis Antiviral therapy in the retrospective analysis was indicated in 48% of patients and in 21% of the prospectively analyzed cohort.

CONCLUSIONS

Histopathology and IHQ combination improves the diagnostic accuracy of CMV hepatitis which translates into a rational us of expensive antiviral therapy and to search for differential diagnosis.

Involvement of ppGalNAc-T6, a new colon cancer marker, in the molecular basis of simple mucin-type O-glycosylated antigen expression

e15060

Background: Abnormal O-glycosylation is one of the most common changes during colon carcinogenesis, leading to the expression of short truncated O-glycan antigens (such as Tn, sialyl-Tn, Tk, and core 6). These structures which are related with the malignant behavior are actively investigated as immunotherapeutic targets. The ppGalNAc-T family enzymes regulate the initial step of mucin O-glycosylation and could be responsible for the altered glycosylation observed in cancer. The objective of this work was to describe the abnormal expression of ppGalNAc-Ts in colon cancer comparing its relationship with incomplete O- glycosylated antigens. Methods: We studied the gene expression of ppGalNAc-Ts in colon cell lines by RT-PCR assays. Using immunohistochemistry we determined ppGalNAc-T6, Tn, sialyl-Tn, Tk, and core 6 expression in 64 colon cancer samples and in 10 normal colon tissues. Results: We found that ppGalNAc-T6 (an enzyme usually restricted to normal placenta, trachea, brain, and pancreas) is expressed by colon cancer cell lines. Using immunohistochemistry we detected ppGalNAc-T6 in 70.3% of cancer samples with no staining in normal colon tissues. Staining pattern was predominantly cytoplasmatic. Staining of Tn, STn, core 6 and Tk antigens was observed in 87,5%, 79,6%, 76,5% and 68.7% of tumors, respectively. We observed a statistically significant relationship between the enzyme expression and Tn antigen (p=0.009) and core 6 (p=0.001). No relationship was observed between the enzyme expression and sialyl-Tn (p = 0.406) and Tk (p= 0.18) antigens. Conclusions: ppGalNac-T6 is a new tumor marker for colon cancer and its expression is related with the accumulation of two O-glycosylated antigens such as Tn and core 6. This is the first evidence in human tissues suggesting that the abnormal expression of a ppGalNac transferase could be in the molecular basis of aberrant O-glycosylated antigens accumulation in cancer.

No significant financial relationships to disclose.

Gallbladder carcinoma in the "Hospital de Clinicas" of Uruguay: 1998-2002. A clinicopathologic study of five cases in 802 cholecystectomies

Five cases of primary carcinoma of the gallbladder are presented. The cases were identified after a study of 802 cholecystectomies in a period of 5 years. The patients are three women and two men between the ages of 43 and 60 years (mean, 55.8 years). In three cases the clinical diagnosis was that of carcinoma, while in two other patients the clinical diagnosis was that of acute cholecystitis. Grossly, all cases were characterized by a gray-white diffuse or focal plaque-like thickening of the gallbladder wall, with loss of the normal velvety mucosal surface and fibrosis of the organ. Histologically, four cases belong to moderately to poorly differentiated adenocarcinoma and were characterized by infiltrative, irregularly shaped and sized glands, islands, nests, and cords. The cells showed pleomorphic nuclei with clumped chromatin and frequent single nucleoli. One case was a mucinous adenocarcinoma characterized by large pools of mucoid material with neoplastic glands and cells "floating" within. Pathologic staging was pT3 in three cases; pT2 in one case; and pT2N1 in one other case. The present study highlights the importance of careful gross and histopathologic evaluation of gallbladders otherwise removed with the history of chronic or acute cholecystitis. In addition, it highlights the incidence of gallbladder carcinoma in a particular institution.