Prevalence and clinical significance of nodular regenerative hyperplasia in liver biopsies

Unexplained Chronically Elevated Aminotransferases: Liver Biopsy Gives Major Information with Therapeutic Implication in One Patient Out of Seven

BACKGROUND & AIMS

Liver biopsy contribution in patients with unexplained elevation of transaminases is not clearly established. The aim was to study liver biopsy contribution in patients with unexplained elevated transaminases strictly defined according to the current guidelines, reflecting the present clinical practice.

METHODS

In a retrospective study, we identified all the liver biopsies performed in patients with elevated transaminases for at least six months. Patients with a particular context, or with an identified cause of liver disease were excluded. The biopsies were classified according to the 4 following injury patterns: hepatitic, biliary, steatotic, vascular.

RESULTS

87 patients were included. Liver biopsy showed minimal changes or a normal histology in 48%, a steatotic pattern in 21%, a hepatitic pattern in 13%, a vascular pattern in 8%, a biliary pattern in 1%, and a mixed pattern in 8%. A cause could be determined in 21% of patients with normal histology, 85% with steatosis, 56% with hepatitis, 75% with biliary, but in none with isolated vascular pattern. Liver biopsy had important clinical and therapeutic implications in 15% of patients, with a diagnosis of autoimmune hepatitis, primary biliary cholangitis or metabolic dysfunction-associated steatohepatitis. Elevation of transaminases > 10 upper normal limit was present in all the patients with confirmed autoimmune hepatitis, but in only 7% of others.

CONCLUSION

Liver biopsy had important clinical and therapeutic implications in 15% of patients. However, the majority of patients had minimal changes without a cause, or minor vascular lesions of uncertain significance.

Nodular Regenerative Hyperplasia: Report of 82 Patients and Systematic Review of Literature

BACKGROUND

Data about the clinical significance and outcome of patients with nodular regenerative hyperplasia are limited.

OBJECTIVE

The aim of this study was to describe the clinical and histopathological characteristics of patients with nodular regenerative hyperplasia and compare our findings with the literature.

METHODS

From January 2015 to March 2021, patients with a diagnosis of nodular regenerative hyperplasia were included. They were extracted from the database of the pathology department of Cliniques universitaires Saint-Luc. Clinical and histological data were retrospectively recorded and complications of portal hypertension and mortality were analyzed. We also performed a systematic review of the literature.

RESULTS

Eighty-two histology-proven nodular regenerative hyperplasia were included. The mean age at diagnosis was 58 ± 14 years. At least one clinical sign of portal hypertension was present in 37 patients (45%), and liver tissue sampling was performed for 29 of them for evaluation of portal hypertension. Conversely, nodular regenerative hyperplasia was an incidental discovery in 27 patients (33%), mostly after liver resection for metastasis (n = 15) or protocol biopsy in liver-transplanted patients (n = 9). The 5-year liver-related mortality was 5%. The 5-year non-liver-related mortality was 20%. Patients diagnosed by clinical suspicion (n = 55) were compared to patients diagnosed incidentally (n = 27). Patients with an incidental diagnosis had more frequently a condition associated with nodular regenerative hyperplasia than patients diagnosed clinically (93% vs. 66%, p = 0.008) and they developed significantly lower liver-related complications (4% vs. 27%, p = 0.01). A systematic review allowed us to compare our patients with 10 case series in the literature.

CONCLUSION

The clinical spectrum of patients with nodular regenerative hyperplasia is heterogeneous, including patients with clinical liver manifestations and patients diagnosed incidentally who could remain free of liver-related complications. This suggests that nodular regenerative hyperplasia could be a histological epiphenomenon as well as a clinical entity.

Porto-sinusoidal Vascular Disease: Classification and Clinical Relevance

Non-cirrhotic portal hypertension (NCPH) is a well-recognized clinico-pathological entity, which is associated with clinical signs and symptoms, imaging, and endoscopic features of portal hypertension (PHT), in absence of cirrhosis. In patients with NCPH without known risk factors of PHT or extrahepatic portal vein thrombosis, the condition is called idiopathic non-cirrhotic portal hypertension (INCPH). There are multiple infectious, immune related causes, systemic diseases, drug and toxin exposures, haematological disorders, and metabolic risk factors that have been associated with this INCPH. However, the causal pathogenesis is still unclear. The Vascular liver disorders interest group group recently proposed porto-sinusoidal vascular disease (PSVD) as a syndromic entity, which provides definite histopathological criteria for diagnosis of NCPH (table 1). The three classical histo-morphological lesions specific for PSVD include obliterative portal venopathy, nodular regenerative hyperplasia, and incomplete septal fibrosis. The PSVD definition includes patients with portal vein thrombosis, PVT, and even those without PHT, thus broadening the scope of diagnosis to include patients who may have presented early, prior to haemodynamic changes consistent with PHT. However, this new diagnosis has pros and cons. The cons include mandating invasive liver biopsy to assess the PSVD histological triad in all patients with NCPH, an erstwhile clinical diagnosis in Asian patients. In addition, the natural history of the subclinical forms of PSVD without PHT and linear progression to develop PHT is unknown yet. In this review, we discuss the diagnosis and treatment of INCPH/PSVD, fallacies and strengths of the old and new schema, pathobiology of this disease, and clinical correlates in an Asian context. Although formulation of standardised diagnostic criteria is useful for comparison of clinical cohorts with INCPH/PSVD, prospective clinical validation in global cohorts is necessary to avoid misclassification of vascular disorders of the liver.

[Portosinusoidal vascular disorder: A paradigm shift]

The term portosinusoidal vascular disorder (PSVD) refers to a clinical-pathological entity that encompasses those patients with intrahepatic vascular damage without cirrhosis at risk of developing severe complications of portal hypertension. Numerous systemic diseases, genetic disorders, and toxic agents have been associated with this pathology, making its diagnosis an important clinical challenge. The recent description of uniform diagnostic criteria and a better understanding of its pathophysiology will allow for better identification of patients, even in early stages of the disease. Although there is currently no effective etiological treatment available, early diagnosis allows for the development of preventive strategies for some severe complications of portal hypertension.

A Narrative Review on Non-Cirrohotic Portal Hypertension: Not All Portal Hypertensions Mean Cirrhosis

Non-cirrhotic portal hypertension (NCPH), also known as idiopathic non-cirrhotic portal hypertension (INCPH) and porto-sinusoidal vascular disorder (PSVD), is a rare disease characterized by intrahepatic portal hypertension (IPH) in the absence of cirrhosis. The precise etiopathogenesis of IPH is an area of ongoing research. NCPH diagnosis is challenging, as there are no specific tests available to confirm the disease, and a high-quality liver biopsy, detailed clinical information, and an expert pathologist are necessary for diagnosis. Currently, the treatment of NCPH relies on the prevention of complications related to portal hypertension, following current guidelines of cirrhotic portal hypertension. No treatment has been studied that aimed to modify the natural history of the disease; however, transjugular intrahepatic porto-systemic shunt (TIPS) placement, shunt and liver transplantation are considerable symptomatic options. In this review, we discuss the heterogeneity of NCPH as well as its etiopathogenesis, clinical presentation and management issues. Starting from the assumption that portal hypertension does not always mean cirrhosis, cooperative studies are probably needed to clarify the issues of etiology and the possible genetic background of this rare disease. This knowledge might lead to better treatment and perhaps better prevention.

Evolving Understanding of Noncirrhotic Portal Hypertension

Although cirrhosis is one of the most common causes of portal hypertension, noncirrhotic portal hypertension can result from hemodynamic perturbations occurring in the prehepatic, intrahepatic, and posthepatic circulation. Intrahepatic portal hypertension can be further subclassified relative to the hepatic sinusoids as presinusoidal, sinusoidal, and postsinusoidal. For many of these differential diagnoses, the etiology is known but the cause of idiopathic noncirrhotic portal hypertension, recently included in porto-sinusoidal vascular disease (PSVD), remains poorly understood. Herein, we discuss the diagnostic pathological features of noncirrhotic portal hypertension, with an emphasis on PSVD.

Interventional Management of Portal Hypertension in Cancer Patients

PURPOSE OF REVIEW

To provide an overview of the classifications and clinical hallmarks of common cancer-related conditions that contribute to the high incidence of portal hypertension in this population and provide an update on currently available interventional radiology therapeutic approaches.

RECENT FINDINGS

In the last few decades, there have been significant advancements in understanding the pathophysiology of portal hypertension. This knowledge has led to the development of safer and more effective minimally invasive approaches. The main objective is to provide alternatives to prevent life-threatening complications from clinically significant portal hypertension and to allow the continuation of cancer treatment interventions that would otherwise be stopped. Clinicians involved in cancer care should be aware of risk factors, associated complications, and management of portal hypertension in cancer patients. Interventional radiology offers minimally invasive alternatives that play a central role in improving clinical outcomes and survival of these patients, allowing the continuation of cancer treatments.

Outcomes of idiopathic versus secondary nodular regenerative hyperplasia of the liver: A longitudinal study of 167 cases

BACKGROUND

Nodular regenerative hyperplasia (NRH) is a rare condition characterized clinically by the development of non-cirrhotic portal hypertension. NRH is the histopathological result in the liver of various systemic disease processes including autoimmune disorders, haematological malignancies and medications. However, natural history of this condition has been limited to small case series while patient outcomes pertaining to different aetiologies of NRH are largely unknown.

METHODS

A retrospective cohort of consecutive patients diagnosed with pathology-confirmed NRH at Mayo Clinic between 2002 and 2017 was identified. The histological diagnosis of NRH was determined by expert liver pathologists. Patients with metastatic liver disease, history of liver transplantation or younger than 18 were excluded. Potential aetiologies of NRH were classified as haematological, rheumatological, drug-associated, miscellaneous or idiopathic. Long-term mortality was analysed using Kaplan-Meier estimation and Cox regression models.

RESULTS

One hundred and sixty-seven consecutive patients with pathology-confirmed NRH were analysed over a 15-year period and followed for a median time of 50 months (1-306 months). The mean age at diagnosis was 53 years. No aetiology or risk factor for NRH was identified in the majority of patients (94, 56.3%), whereas an associated, possibly causal, condition was found in 73 patients (secondary NRH). The most common presenting feature was elevated liver tests (80%), but no significant differences in laboratory tests were seen based on aetiology of NRH. Compared to idiopathic NRH, those with an identified cause had a higher rate of splenomegaly at presentation (54% vs. 27%, p = 0.002). Portal hypertension-related complications at diagnosis were common, with ascites present in one-third of patients. Overall transplant-free survival was 63% at 5 years. Median survival in idiopathic NRH was 9.4 years compared to 7.3 years in secondary NRH. Age, renal function and volume status at presentation were significantly associated with survival; however, MELD score was not.

CONCLUSIONS

The rates of liver-related complications and mortality in NRH are low, and only a small number of patients ultimately require liver transplantation. Most patients do not have an identified risk factor or aetiology for NRH, and liver-related outcomes do not appear to differ based on associated, possibly causal, conditions.

Clinical Course of Porto-Sinusoidal Vascular Disease Is Distinct From Idiopathic Noncirrhotic Portal Hypertension

BACKGROUND & AIMS

Porto-sinusoidal vascular disease (PSVD) was recently proposed as novel clinical entity characterized by typical histological changes with or without portal hypertension (PH) in the absence of cirrhosis. Thus, we aimed to describe clinical characteristics and the outcome of PSVD patients and to compare these to patients meeting traditional idiopathic non-cirrhotic portal hypertension (INCPH) criteria.

METHODS

Patients undergoing liver biopsy (baseline) ±hepatic venous pressure gradient (HVPG) measurement at the Vienna General Hospital between 2000-2019 were screened for PSVD and INCPH criteria.

RESULTS

91 patients were diagnosed with PSVD of which 28 (30.8%) also fulfilled INCPH criteria (INCPH+/PSVD+). Specific histological and specific clinical PH signs were found in 72 (79.1%) and 54 (59.3%) patients, respectively. INCPH+/PSVD+ showed higher Child-Pugh-scores (7±2 vs 6±1 points; P = .002) and a higher prevalence of decompensation (57.1% vs 28.6%; P = .009) than INCPH-/PSVD+ patients. Importantly, hepatic decompensation after three years (3Y) occurred in 11.2% of PSVD patients with specific clinical signs of PH, while no decompensation occurred in patients with only specific histological or with unspecific clinical/histological signs (P = .002). When categorizing by INCPH definition, 3Y decompensation was 13.4% in INCPH+/PSVD+ and 3.8% in INCPH-/PSVD+ (P = .120). While overall mortality was similar in INCPH+/PSVD+ (n = 6; 21.4%) and INCPH-/PSVD+ (n = 10; 15.9%) patients (P = .558), liver-related mortality tended to be higher in INCPH+/PSVD+ (6.9%) than in INCPH-/PSVD+ (0%; P = .078).

CONCLUSION

Novel PSVD criteria facilitate diagnosis. Compared to INCPH, clinical course of PSVD patients is more favorable. Importantly, specific signs of PH including varices and collaterals are associated with hepatic decompensation and mortality.

Mild changes of hepatic nodular regenerative hyperplasia may cause portal hypertension and be visible on reticulin but not hematoxylin and eosin staining

Nodular regenerative hyperplasia (NRH) can manifest as alternating parenchymal compression/expansion on hematoxylin and eosin (H&E) staining and as reticulin collapse/nodularity on reticulin staining. Histologic diagnosis can be challenging, especially when there is mild disease and on limited biopsy samples. We reviewed clinical and histologic parameters in a large series of NRH. We identified 60 liver specimens convincingly showing changes of NRH and reviewed them for clinical (age, sex, symptoms, lab values, portal hypertension [PHTN], NRH etiology) and histologic (inflammation, sinusoidal dilation, cholestasis, architectural change, portal vascular abnormalities, degree of changes on reticulin) parameters. The cases came from 28 women and 32 men (median age: 54 years). Most (55, 92%) were biopsies. Thirty patients were symptomatic. Forty-five cases showed mild NRH changes on reticulin; 24 of these (53%) showed them on H&E as well. Fifteen demonstrated well-developed changes on reticulin, which were always seen on H&E as well. Sinusoidal dilation was commonly observed in both of these subgroups (88% overall). Portal vascular abnormalities were seen in 33%. Well-developed NRH was diffuse more often than mild NRH (53% vs. 4%, P < 0.0001). Twenty-nine patients had clinically confirmed or likely PHTN. Of these, 21 showed mild and 8 showed well-developed NRH changes; only 3 had concomitant advanced fibrosis. Chemotherapy was the most frequent known cause of NRH; 30 patients lacked any definite etiology. NRH can be difficult to diagnose on biopsy, particularly since mild changes may be visible on reticulin but not H&E; even these patients can have PHTN. Additionally, NRH is often idiopathic, potentially lowering clinical and pathologic suspicion. Pathologists should have a low threshold for ordering reticulin stains, especially when a patient is known to have PHTN. Sinusoidal dilation, while nonspecific, commonly accompanies NRH.

Porto-sinusoidal vascular disease: proposal and description of a novel entity

Portal hypertension in the absence of portal vein thrombosis and without cirrhosis, but with mild or moderate alterations of liver histology (eg, obliterative venopathy, nodular regenerative hyperplasia, or incomplete septal cirrhosis) is being increasingly recognised. Owing to the heterogeneity of causes and histological findings, a substantial number of terms have been used to describe such idiopathic non-cirrhotic portal hypertension. Patients with the same clinical and histological features exist, but without portal hypertension at the time of diagnosis. Therefore, improved criteria are needed to define this form of liver disease. Here, we propose the term porto-sinusoidal vascular disease, since all lesions found involve the portal venules or sinusoids. The definition of this entity is based on the characteristic absence of cirrhosis with or without signs of portal hypertension or histological lesions. The presence of known causes of liver disease does not rule out porto-sinusoidal vascular disease, but specific causes of vascular liver disease are excluded from its definition. The diagnosis of porto-sinusoidal vascular disease is based on liver biopsy and might include signs specific for portal hypertension with normal or mildly elevated liver stiffness values and no complete portal vein thrombosis. We provide simple diagnostic criteria, because agreement on a uniform nomenclature is an essential requirement for future collaborative studies.

The continuous rediscovery and the benefit-risk ratio of thioguanine, a comprehensive review

Introduction: In the 1950s, thioguanine (TG), a thiopurine-derivative together with azathioprine (AZA) and mercaptopurine (MP), were developed for the treatment of childhood leukemia. Over the years, the use of TG was also explored for other, mainly immune-mediated and inflammatory, diseases such as in the field of dermatology and rheumatology (e.g. psoriasis, systemic lupus erythematosus (SLE)) and gastroenterology and hepatology (e.g. inflammatory bowel diseases (IBD), autoimmune hepatitis).Areas covered: This review provides a comprehensive overview of all the clinical uses of TG and describes its mechanism of action, pharmacokinetic/pharmacodynamic features, and toxicity.Expert opinion: Thioguanine has shown beneficial clinical effects in hematological (particularly leukemia) and several immune-inflammatory diseases including psoriasis, SLE, polycythemia vera, Churg-Strauss syndrome, IBD, collagenous sprue, refractory celiac disease, and autoimmune hepatitis. Thioguanine is not effective in treating solid-cancers. At relatively low dosages, i.e. 0.2- 0.3mg/kg/day or 20 mg/day, TG has a favorable risk-benefit ratio and is a safe and effective drug in the long-term treatment of amongst other IBD patients. Thioguanine toxicity, especially myelotoxicity, and hepatotoxicity, including nodular regenerative hyperplasia (NRH) of the liver, is limited when dosed adequately. The occurrence of NRH appears dose-dependent and has been especially described during high dose TG above 40 mg/day.

Liver stiffness measurement in patients with nodular regenerative hyperplasia undergoing magnetic resonance elastography

PURPOSE

Nodular regenerative hyperplasia (NRH) may mimic cirrhosis at imaging. We aim to investigate the effect of NRH on liver stiffness measurement (LSM) obtained with magnetic resonance elastography (MRE).

METHODS

This retrospective, Institutional Review Board-approved study included 37 subjects with NRH (Group 1) and no or minimal fibrosis (F0-F1), a control group (Group 2) made of 30 subjects with non-advanced fibrosis (F0-F2), and a control group (Group 3) made of 30 subjects with advanced fibrosis (F3-F4), all with available MRE. LSM was measured in each subject along with assessment of hepatic morphological features of cirrhosis and signs of portal hypertension. The significance of the difference in mean LSM between Group 1 and 2 and between Group 1 and 3 was evaluated using the Mann-Whitney U test. The difference in distribution of imaging features among groups was assessed using the Pearson χ2 or Fisher exact test.

RESULTS

The mean ± SD LSM in Group 1 (3.56 ± 1.10 kPa) was significantly higher compared to Group 2 (2.91 ± 0.52 kPa, P = 0.019) and significantly lower compared to Group 3 (7.18 ± 2.08 kPa, P < 0.001). Twelve (32%) patients with NRH had LSM ≥ 4.11 kPa, and 6 (16%) patients had LSM ≥ 4.71 kPa. Surface nodularity (P = 0.032) and caudate lobe hypertrophy (P = 0.004) were more commonly visualized in Group 1 than in Group 2. At least one feature of portal hypertension was observed in 16 (43%) NRH subjects.

CONCLUSION

NRH may increase the LSM obtained with MRE and may represent a confounding factor when using liver stiffness for the non-invasive diagnosis of fibrosis.

Abdominal Surgery in Patients With Idiopathic Noncirrhotic Portal Hypertension: A Multicenter Retrospective Study

In patients with idiopathic noncirrhotic portal hypertension (INCPH), data on morbidity and mortality of abdominal surgery are scarce. We retrospectively analyzed the charts of patients with INCPH undergoing abdominal surgery within the Vascular Liver Disease Interest Group network. Forty-four patients with biopsy-proven INCPH were included. Twenty-five (57%) patients had one or more extrahepatic conditions related to INCPH, and 16 (36%) had a history of ascites. Forty-five procedures were performed, including 30 that were minor and 15 major. Nine (20%) patients had one or more Dindo-Clavien grade ≥ 3 complication within 1 month after surgery. Sixteen (33%) patients had one or more portal hypertension-related complication within 3 months after surgery. Extrahepatic conditions related to INCPH (P = 0.03) and history of ascites (P = 0.02) were associated with portal hypertension-related complications within 3 months after surgery. Splenectomy was associated with development of portal vein thrombosis after surgery (P = 0.01). Four (9%) patients died within 6 months after surgery. Six-month cumulative risk of death was higher in patients with serum creatinine ≥ 100 μmol/L at surgery (33% versus 0%, P < 0.001). An unfavorable outcome (i.e., either liver or surgical complication or death) occurred in 22 (50%) patients and was associated with the presence of extrahepatic conditions related to INCPH, history of ascites, and serum creatinine ≥ 100 μmol/L: 5% of the patients with none of these features had an unfavorable outcome versus 32% and 64% when one or two or more features were present, respectively. Portal decompression procedures prior to surgery (n = 10) were not associated with postoperative outcome. Conclusion: Patients with INCPH are at high risk of major surgical and portal hypertension-related complications when they harbor extrahepatic conditions related to INCPH, history of ascites, or increased serum creatinine.

Paraneoplastic nodular regenerative hyperplasia of the liver associated with placental site trophoblastic tumor

•NRH-L is a rare disease that may lead to non-cirrhotic portal hypertension.•NRH-L may present as a paraneoplastic disorder, complicating oncologic treatment.•This is the first case of NRH-L as a potential paraneoplastic disorder due to PSTT.

Idiopathic Portal Hypertension

Idiopathic portal hypertension (IPH) is a rare disorder characterized by clinical portal hypertension in the absence of a recognizable cause such as cirrhosis. Laboratory tests often reveal a preserved liver function with anemia, leukopenia, and thrombocytopenia due to splenomegaly. Imaging studies reveal signs of portal hypertension, whereas liver stiffness and portal pressure values are usually normal or slightly elevated. Liver biopsy is considered mandatory in order to rule out other causes of portal hypertension, mainly cirrhosis. Liver histology may only show subtle or mild changes, and the definite diagnosis of IPH often requires an expert pathologist and a high-quality specimen. The most frequent clinical presentation is variceal bleeding. Ascites is rarely observed initially, although it may occasionally appear during follow-up. Typical histological findings associated with IPH have been described in patients without portal hypertension, probably representing early stages of the disease. Although the pathophysiology of this entity remains largely unknown, it is frequently associated with underlying immunological disorders, bacterial infections, trace metal poisoning, medications, liver circulatory disturbances, and thrombotic events. The long-term prognosis of patients with IPH, where ascites and the underlying condition are important prognostic factors, is better than in patients with cirrhosis. Treatments that modify the natural history of the disease remain an unmet need, and management of IPH is frequently restricted to control of portal hypertension-related complications.

Portal Cavernoma Mimicking Pancreatic Malignancy

Portal cavernoma colangiopathy (PCC) is an uncommon cause of portal hypertension, and it is an important differential diagnosis of pancreatic malignancy given the expanded network of collateral vessels. On imaging studies, portal cavernoma can be seen as a hypoechoic mass, possibly associated with distal common bile duct obstruction. Most cases occur in non-cirrhotic patients. During the symptomatic phase, these patients carry a high-risk of complications related to sustained biliary obstruction. We report a unique patient with obstructive jaundice and a presumed pancreatic mass that proved to be a portal cavernoma complicated by PCC in the setting of nodular regenerative hyperplasia of the liver.

Nodular Regenerative Hyperplasia of the Liver in Patients with IBD Treated with Allopurinol-Thiopurine Combination Therapy

BACKGROUND

Thiopurine therapy, particularly thioguanine, has been associated with nodular regenerative hyperplasia (NRH) of the liver. Combination therapy of allopurinol and an adapted low-dose thiopurine leads to a pharmacokinetic profile that has similarities to that of thioguanine. Therefore, allopurinol-thiopurine combination therapy may also be associated with NRH of the liver. We assessed the prevalence of NRH in patients with inflammatory bowel disease (IBD) treated with allopurinol-thiopurine combination therapy by liver biopsy specimen examination.

METHODS

An observational, cross-sectional study was conducted in a Dutch IBD-referral center. Adult patients with IBD, treated for at least 1 year with allopurinol-thiopurine combination therapy were eligible. All patients underwent a liver biopsy, after standard laboratory and thiopurine metabolite concentration assessments. Histopathology was assessed by an experienced liver pathologist.

RESULTS

Twenty-two patients with IBD were included. The mean duration of combination therapy at the time of the liver biopsy was 24.7 months (SD 5.7). NRH was observed in one of the biopsies (4.8%), any grade of nodularity was observed in 3 biopsy specimens (14%). Other findings included phlebosclerosis (24%), perisinusoidal fibrosis (81%), sinusoidal dilatation (43%), perivenular fibrosis (14%), and periportal fibrosis (29%). Around the time of biopsy, the median 6-thioguanine nucleotide and 6-methylmercaptopurine ribonucleotide concentrations were 705 pmol × 10 red blood cells (RBC) (interquartile range 498-915) and 355 pmol × 10 RBC (interquartile range 225-670).

CONCLUSIONS

The prevalence of histologically assessed NRH in patients with IBD, who were treated with allopurinol-thiopurine combination therapy, was 5%. This percentage is in line with thiopurine-naive and thioguanine-using patients with IBD. None of the included patients had clinical symptoms or signs suggestive of (noncirrhotic) portal hypertension.

Nodular regenerative hyperplasia rarely leads to liver transplantation: A 20-year cohort study in all Dutch liver transplant units

BACKGROUND

Nodular regenerative hyperplasia is an uncommon liver condition associated with several autoimmune disorders and drugs. The clinical symptoms of nodular regenerative hyperplasia vary from asymptomatic to severe complications of portal hypertension (nodular regenerative hyperplasia-syndrome).

OBJECTIVE

The purpose of this study was to identify the prognosis and optimal management, as well as the role of liver transplantation, in nodular regenerative hyperplasia.

METHODS

The pathology databases of all three Dutch liver transplant units were retrospectively scrutinised for explanted livers diagnosed with nodular regenerative hyperplasia or without clear diagnosis. Pre- and post-transplantation clinical, biochemical, radiological and histological information was obtained from electronic and paper records.

RESULTS

In total, 1886 patients received a liver transplant. In 255 patients, nodular regenerative hyperplasia could not be excluded. After detailed chart review, the native livers of 11 patients (0.6%) (82% male, median age: 44 years) displayed nodular regenerative hyperplasia. Seven patients (64%) had underlying disorders or drug exposure which possibly caused nodular regenerative hyperplasia. Laboratory and imaging abnormalities were present in all patients but did not contribute to the diagnosis of nodular regenerative hyperplasia. Five-year survival was 73% (median follow-up: four years, range: 2-248 months).

CONCLUSION

Nodular regenerative hyperplasia is a rare finding in patients, predominantly young males, transplanted for end-stage liver disease with unknown aetiology. Nonetheless, liver transplantation may have an important role in end-stage nodular regenerative hyperplasia-syndrome.