Histopathology of the liver in non‐cirrhotic portal hypertension of unknown aetiology

Abstract

Non-cirrhotic, long-standing portal hypertension of unknown aetiology is being re-evaluated histopathologically and clinically. In this study, we examined 107 livers with this condition (92 wedge biopsy and 15 autopsy specimens) from five institutions in Japan. These cases were histologically categorized into four groups: idiopathic portal hypertension (66 cases), nodular regenerative hyperplasia (14 cases), partial nodular transformation (two cases), and incomplete septal cirrhosis (25 cases). These four groups shared several histological features: dense portal fibrosis with portal venous obliteration and intralobular slender fibrosis. In addition, the histopathological features characteristic of one group were also found to a mild degree in other groups. The histopathological lesions preceding portal venous obliteration remain speculative. However, the portal venous obliteration may be responsible for the occurrence of sustained portal hypertension and several of the pathological changes in these livers. It seems likely that idiopathic portal hypertension, nodular regenerative hyperplasia, partial nodular transformation and incomplete septal cirrhosis comprise a family of non-cirrhotic, long-standing portal hypertension in Japan, and the histological differences between them may reflect chronological progression of a single disease.

Changes in lymph vessels and portal veins in the portal tract of patients with idiopathic portal hypertension: A morphometric study

“…phlebosclerosis, intimal thickening or smooth muscle hyperplasia around portal veins, and a reduction in portal veins luminal area. [4][5][6] The results of the morphological and morphometrical analyses in the present study also confirmed smooth muscle hyperplasia and reduced luminal area of the portal veins.…”

Altered expression of heme oxygenase-1 in the livers of patients with portal hypertensive diseases

“…Namely, IPH is thought to result from presinusoidal vasoconstriction, causing a reduction of perfusion pressure and a decrease in local shear stress. 31,32 By contrast, cirrhotic livers are likely to be exposed to an elevation of intrasinusoidal pressure accompanied by hyperhemodynamic states, [33][34][35][36] implicating an increase in regional shear stress in sinusoids. It is therefore possible to hypothesize that Kupffer cells serve as a putative sensor cell that detects local hemodynamic changes in sinusoids and thereby alter their heme-degrading ability through the HO-1 induction.…”

Expression of Connective Tissue Growth Factor in the Human Liver with Idiopathic Portal Hypertension

“…IPH was histopathologically diagnosed according to the criteria proposed by the Japanese Study Group of Intrahepatic Haemodynamic Alterations (12,28). Wedge liver biopsy specimens and peripheral blood samples were collected from each patient.…”

“…Accumulated evidence indicates that IPH is an entirely distinct disease from liver cirrhosis. Aetiopathogenically, IPH has been associated with chronic abdominal infection (9), abnormal T-cell activation by continuous antigen stimulation (10), immunological abnormalities initiated by HLA-DR antigen expression by the portal tract microvasculature (11,12), exposure to toxic substances or drugs (13), and blood coagulation abnormalities (14). However, the pathogenesis of IPH remains poorly understood.…”