Mercaptopurine-induced hepatoportal sclerosis in a patient with Crohn's disease

Exploring the link: Porto-sinusoidal vascular disorder and inflammatory bowel disease - A comprehensive narrative review

Porto-sinusoidal vascular disorder (PSVD) encompasses a group of vascular disorders characterized by lesions involving the portal venules and sinusoids, independent of the presence of portal hypertension (PH), and for which liver biopsy is essential for diagnosis. PSVD has been shown to be common in patients with immune-mediated diseases, including inflammatory bowel disease (IBD). The association between PSVD and the use of thiopurines and thioguanine in patients with IBD has been well established. In addition, research suggests an association between PSVD and IBD, even in cases where patients haven't been exposed to specific medications, probably related to changes in intestinal permeability. The identification and management of patients with known IBD and PSVD is a challenge for gastroenterologists. This narrative review aims to summarize the currently available data on the association between IBD and PSVD and provide practical suggestions for the management of this group of patients.

Portosinusoidal Vascular Disorder: A Heretofore Unrecognized Manifestation of Sickle Cell Disease?

Portosinusoidal vascular disorder (PSVD) is a recently proposed histopathologic entity that encompasses a spectrum of often subtle hepatic microvascular lesions and related microarchitectural abnormalities. Clinical manifestations may arise years after histologic diagnosis and include extrahepatic portal vein thrombosis and portal hypertension. While the histopathologic features of PSVD have been associated with numerous clinical conditions, most notably prothrombotic/vasculopathic disorders, PSVD has not yet been described in sickle cell disease. This gap is striking given the central role of microvascular dysfunction in sickle cell disease and well-described patterns of hepatic injury and dysfunction in this population. This case series is the first to explore the prevalence and pathogenesis of PSVD in sickle cell disease. Forty-one diagnostically adequate liver biopsies from patients with sickle cell disease were identified across the archives of 5 tertiary medical centers. All biopsies exhibited at least 1 histopathologic feature associated with PSVD (mean 3.8 features/case). Overall, 90.2% of patients met the criteria for a diagnosis of PSVD based on the presence of specific histopathologic and/or clinical findings. Immunohistochemical stains for von Willebrand factor, CD34, and glutamine synthetase were performed on 36 cases (87.8%). Aberrant (centrilobular sinusoidal) CD34 and von Willebrand factor staining was present in 97.2% and 86.1% of cases, respectively. Glutamine synthetase reactivity was at least mildly decreased in zone 3 hepatocytes in 52.8% of cases. We posit that chronic erythrocyte sickling results in dysfunction and remodeling of the portal microvasculature, culminating in regression of zone 3 hepatocytes. The presence of PSVD may explain, at least in part, the hepatic dysfunction observed in this patient population. These patients may also benefit from extended clinical surveillance for portal hypertension and other complications. While subtle and prone to overdiagnosis, the features of PSVD should be carefully considered when interpreting liver biopsies from patients with sickle cell disease.

Oxaliplatin-related Portal Hypertension Complicated with Esophageal Varices and Refractory Massive Ascites

Oxaliplatin, widely used as a chemotherapy drug for colorectal cancer, is known to cause various adverse reactions. In particular, special attention for the development of portal hypertension associated with porto-sinusoidal vascular disease is necessary, as it is a serious adverse life-threating reaction, although rare. We herein report a case of oxaliplatin-related portal hypertension that developed several years after oxaliplatin administration and led to esophageal varices and refractory massive ascites. Clinical physicians should be aware of the possibility of oxaliplatin-induced portal hypertension and its possible development over a long period after discontinuation of the drug.

Immune rebalancing by oral immunotherapy: A novel method for getting the immune system back on track

Immune modulating treatments are often associated with immune suppression or an opposing anti-inflammatory paradigm. As such, there is a risk of exposing patients to infections and malignancies. Contrarily, eliciting only mild immune modulation can be insufficient for alleviating immune-mediated damage. Oral immunotherapy is a novel approach that uses the inherent ability of the gut immune system to generate signals that specifically suppress inflammation at affected sites, without inducing generalized immune suppression. Oral immunotherapy is being developed as a method to rebalance systemic immunity and restore balance, getting it back on track, rather than pushing the immune response too much or too little in opposing directions. Here, I review recent preclinical and clinical data examining the technique and describe its primary advantages.

Obliterative portal venopathy: A histopathologic finding associated with chronic antibody-mediated rejection in pediatric liver allografts

The significance of post-transplant HLA DSA and chronic AMR in LT is an emerging field of study. Although OPV has previously been described as a histopathologic finding in DSA-positive adult LT recipients, it was not included in the recent Banff criteria for chronic AMR. Our aim was to describe the association between OPV and chronic AMR in pediatric LT recipients. A retrospective review of 67 liver biopsies performed between November 2014 and April 2016 in 45 pediatric LT recipients identified four patients with OPV. Clinical status, liver biochemistry, the presence of DSA, and available non-HLA antibody testing, as well as histopathologic features of chronic AMR, were assessed. All four patients with OPV had class II DSA and histopathologic features of chronic AMR based on the Banff criteria. Two patients were noted to have non-HLA antibodies. Three patients are undergoing treatment with IVIG but have persistent DSA. Two patients have graft failure and are awaiting retransplantation. In conclusion, OPV is a histopathologic finding associated with chronic AMR in pediatric LT recipients. Further studies are needed to elucidate whether OPV is reversible and/or amenable to medical therapy.

Hepatic complications induced by immunosuppressants and biologics in inflammatory bowel disease

The incidence of inflammatory bowel diseases (IBD) is rising worldwide. The therapeutic options for IBD are expanding, and the number of drugs with new targets will rapidly increase in coming years. A rapid step-up approach with close monitoring of intestinal inflammation is extensively used. The fear of side effects represents one the most limiting factor of their use. Despite a widespread use for years, drug induced liver injury (DILI) management remains a challenging situation with Azathioprine and Methotrexate. DILI seems less frequent with anti-tumor necrosis factor agents and new biologic therapies. The aim of this review is to report incidence, physiopathology and practical guidelines in case of DILI occurrence with the armamentarium of old and new drugs in the field of IBD.

Safety of treatments for inflammatory bowel disease: Clinical practice guidelines of the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD)

Inflammatory bowel diseases are chronic conditions of unknown etiology, showing a growing incidence and prevalence in several countries, including Italy. Although the etiology of Crohn's disease and ulcerative colitis is unknown, due to the current knowledge regarding their pathogenesis, effective treatment strategies have been developed. Several guidelines are available regarding the efficacy and safety of available drug treatments for inflammatory bowel diseases. Nevertheless, national guidelines provide additional information adapted to local feasibility, costs and legal issues related to the use of the same drugs. These observations prompted the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD) to establish Italian guidelines on the safety of currently available treatments for Crohn's disease and ulcerative colitis. These guidelines discuss the use of aminosalicylates, systemic and low bioavailability corticosteroids, antibiotics (metronidazole, ciprofloxacin, rifaximin), thiopurines, methotrexate, cyclosporine A, TNFα antagonists, vedolizumab, and combination therapies. These guidelines are based on current knowledge derived from evidence-based medicine coupled with clinical experience of a national working group.

Review article: the association between nodular regenerative hyperplasia, inflammatory bowel disease and thiopurine therapy

BACKGROUND

Nodular regenerative hyperplasia (NRH) is increasingly being recognised in patients with inflammatory bowel disease (IBD). However, the pathogenesis and incidence of NRH in IBD, and the putative roles played by azathioprine (AZA), mercaptopurine (MP), or tioguanine (TG) remain unclear.

AIMS

To summarise the data on the association between NRH and thiopurine therapy in patients with IBD.

METHODS

A literature search was performed in PubMed and MEDLINE databases using the keywords 'nodular regenerative hyperplasia AND (inflammatory bowel disease OR Crohn's disease OR ulcerative colitis) AND (azathioprine OR mercaptopurine OR tioguanine OR thioguanine).' No time limit was placed on studies included.

RESULTS

Inflammatory bowel disease patients treated with AZA have a cumulative incidence of NRH of approximately 0.6% and 1.28% at 5 and 10 years, respectively, whereas those treated with high-dose TG (>40 mg/day) have a frequency of NRH of up to 62%, which is higher in patients with elevated liver enzymes and/or thrombocytopaenia than those without these abnormalities (frequency 76% vs. 33%). Conversely, low-dose TG therapy (<20 mg/day) is relatively safe, with no cases of NRH observed. NRH has also been found in 6% of operated thiopurine-naïve IBD patients. Male gender, older age, and stricturing disease/small bowel resection have been consistently identified as high-risk factors for NRH.

CONCLUSIONS

The pathogenesis of nodular regenerative hyperplasia in patients with IBD is complex and multifactorial involving disease-specific, genetic and iatrogenic risk factors. Clinicians should maintain a high index of suspicion for diagnosing nodular regenerative hyperplasia, especially in IBD patients with high-risk factors on thiopurine therapy, regardless of the presence of laboratory abnormalities.

Obliterative portal venopathy: a clinical and histopathological review

Non-cirrhotic portal hypertension (NCPH) is characterized by the elevation of the portal pressure in the absence of cirrhosis. Obliterative portal venopathy (OPV) as a cause of NCPH is being increasingly diagnosed, especially after recent reports of its occurrence in patients with HIV using didanosine. Patients usually present with episodes of variceal hemorrhage and other features of portal hypertension including jaundice, ascites, encephalopathy and hepatopulmonary syndrome. Hepatic synthetic function is typically well preserved and the laboratory evaluation in OPV patients typically reveals only mild nonspecific hematological abnormalities chiefly related to hypersplenism. Its diagnosis remains a challenge and patients are often mistakenly diagnosed as having cirrhosis. Despite the increasing recognition of OPV, its etiology and pathogenesis are still unclear. A number of etiologies have been proposed including genetic predisposition, recurrent bacterial infections, HIV infection and highly active antiretroviral therapy, an altered immune response, hypercoagulability, and exposure to chemicals and certain medications. Histopathological evaluation remains critical in excluding cirrhosis and other causes of portal hypertension, and is the only way of definitively establishing the diagnosis of OPV. Clinicians should have a high index of suspicion for OPV in patients who present with variceal bleeding and splenomegaly and who do not have other features of cirrhosis. The purpose of this review is to summarize the known etiologies for OPV and its associated clinical aspects and correlations, and to also provide ample histophotomicrographs of OPV to aid in the diagnosis. It will also help raise awareness of this entity amongst pathologists and clinicians alike.