Dissociation in hepatic vein pressure gradient, liver stiffness measurement and complications in histological subtypes of porto-sinusoidal vascular disease

Background and aims Portosinusoidal vascular disease (PSVD) is a broad term encompassing varied histological patterns with changes in portal tracts and sinusoids without cirrhosis. We aimed to assess whether there is any clinical and pathological difference among the various histological categories of PSVD. Patients and methods This study included liver biopsy cases classified as PSVD (2020-2022). Clinical and laboratory parameters were obtained from the electronic records. PSVD cases were histologically categorised as obliterative portal venopathy (OPV), OPV with fibrosis (OPV-F), incomplete septal cirrhosis (ISC), nodular regenerative hyperplasia (NRH), mega sinusoids with fibrosis (MSF) and unclassified. Follow-up complications were recorded. Results PSVD categories were OPV (45 (26%)), OPV-F (37 (21.4%)), ISC (20 (11.6%)), NRH (19 (11%)), MSF (19 (11%)) and unclassified (33 (19%)). Elevated hepatic venous pressure gradient (HVPG) was noted in OPV-F (10 (IQR: 12-14.7)) and ISC (12 (IQR: 9-14)) mm Hg with higher fibrosis quantity in liver tissue and elevated procollagen III aminoterminal propeptide, which correlated with HVPG. On immunohistochemistry, OPV-F and ISC showed lesser expression of ADAMT13 in liver biopsies (p<0.001). On follow-up, ascites development was more in OPV-F and ISC than in other categories (p=0.001). Higher liver stiffness measurement (LSM) values were recorded in MSF and NRH, compared with other categories, but it did not correlate with fibrosis in liver biopsy. Conclusions OPV-F and ISC had higher HVPG, fibrosis, and more ascites development on follow-up than the other categories of PSVD, and all are not the same. In contrast, MSF and NRH have spuriously high LSM.