Liver histology and histochemistry in Wilson disease

Addressing the Challenges in the Diagnosis and Management of Pediatric Wilson's Disease-Case Report and Literature Review

Wilson's disease (WD) is an autosomal recessive disorder, in which the metabolism of copper is affected by metal accumulation in several organs that causes gradual organ degeneration. Since Wilson's initial description of WD over a century ago, there have been significant improvements in understanding and managing the condition. Nevertheless, the ongoing gap between the onset of symptoms and diagnosis highlights the difficulties in identifying this copper overload disorder early. Despite being a treatable condition, detecting WD early remains a challenge for healthcare professionals at all levels of care, likely due to its rarity. The key challenge is, therefore, to educate physicians on how to identify atypical or infrequent symptoms of WD, prompting them to consider the diagnosis more carefully. The purpose of our review is to draw attention to the difficulties associated with diagnosing pediatric WD, starting from our personal experience of a complex case and then examining relevant literature. In summary, the diagnosis of WD in children is intricate and requires a heightened level of suspicion to identify this infrequent condition. A thorough evaluation by a multidisciplinary team of physicians, along with genetic testing, histopathologic examination, and specialized imaging studies, may be necessary to confirm the diagnosis and guide treatment.

Wilson disease and the differential diagnosis of its hepatic manifestations: a narrative review of clinical, laboratory, and liver histological features

Objective

The goal of the present work is to provide an overview of the differential diagnosis of Wilson disease.

Background

Wilson disease is a rare condition due to copper accumulation primarily in the liver and brain. Although there is no definitive cure, current anti-copper treatments are associated with better outcomes if initiated early and if the diagnosis is made promptly. However, diagnostic delays are frequent and often Wilson disease represents a diagnostic challenge. The diagnosis ultimately relies on a combination of clinical, laboratory and genetic findings, and it is crucial that clinicians list Wilson disease in their differential diagnosis, especially in patients presenting with a hepatocellular pattern of liver injury. Some biochemical and liver histological features of Wilson disease overlap with those of more common conditions including nonalcoholic fatty liver disease, alcohol-associated liver disease, and autoimmune hepatitis. In particular, hepatic steatosis, hepatocyte glycogenated nuclei, ballooning degeneration, and Mallory-Denk bodies are often identified in Wilson disease as well as more common liver diseases. In addition, the natural history of liver damage in Wilson disease and the risk of developing liver cancer are largely understudied.

Methods

We conducted an enlarged review of published papers on Wilson disease focusing on its diagnosis and distinctive clinical and liver pathology features in relation to common non-cholestatic liver diseases with the final goal in aiding clinicians in the diagnostic process of this rare but treatable condition.

Conclusions

Aside from markedly altered copper metabolism, Wilson disease has essentially no pathognomonic features that can distinguish it from more common liver diseases. Clinicians should be aware of this challenge and consider Wilson disease in patients presenting with a hepatocellular pattern of liver injury.

Delineation of the healthy rabbit liver by immunohistochemistry - A technical note

Liver diseases pose a big global health problem and liver failure may result from viral infection, overnutrition or tumors. Studying pathologic liver tissue demands for accurate and specific histological stainings and immunohistochemical labellings, including chromogenic and fluorescent approaches. Moreover, a reliable set of healthy liver stainings and labellings are required, to provide a baseline or reference for the pathological situation. Here, we used the liver tissue of a healthy rabbit and compared different histological key steps, such as paraffin embedding after formalin fixation versus cryopreservation; or an antigen retrieval (AR) step in processing paraffin sections versus the same procedure without AR; or chromogenic with fluorescent detection system, respectively. Moreover, we provide images of serial sections, where we stained the same morphological structure with different markers, including collagen I, collagen III, fibronectin, α-SMA, elastin, protease-activated receptor-2 (PAR-2) which is an inflammation-related marker, ki67 for proliferating cells, and orcein (as negative control for pathological aberrations like Wilson disease). Differences between conditions were quantitatively assessed by measuring the colour intensity. Generally, we observed that cryosections exhibited a stronger signal intensity in immunohistochemically labelled sections than in paraffin sections; however, the strong staining got slurred, which sometimes hampered proper identification of morphological structures at higher magnifications. Moreover, there was a clear increase in signal intensity for paraffin sections when an AR step was performed compared to condition without AR. Results for mouse isotype staining as a negative control clearly supported those findings. Different stainings of the portal triad, the central vein and the bile ducts revealed a clear-cut distribution of extracellular matrix components, with prominent fibronectin and elastin around the lumen of the central vein as well as a patchy PAR-2 expression. As for the bile ducts, complete absence of α-SMA and PAR-2 was found at the margins, however, collagen I expression and elastin were positive and showed a strong signal. Like this, we provide useful and valuable reference images for researchers using the rabbit liver model. It may help to decide which of the immunohistochemical protocols are valuable to reach a certain aim and which protocols lead to the best visualization of the target structure.