Metallothionein immunohistochemistry has high sensitivity and specificity for detection of Wilson disease

Validation of Metallothionein Immunohistochemistry as a Highly Sensitive Screening Test for Wilson Disease

Wilson disease (WD) is a rare autosomal recessive condition with protean clinical manifestations that result from biallelic ATP7B mutations. However, nondestructive tissue tests to be applied clinically to tissue specimens are not widely available to effectively assess patients for possible WD. Previously, we showed that metallothionein (MTH) immunohistochemistry (IHC) has a high sensitivity and specificity for WD diagnosis and, thus, represents a potentially powerful diagnostic tool that can be used in routine histologic sections. This study aimed to validate this finding in a large cohort of bona fide patients with WD and to correlate metallothionein expression with other histologic features. We identified 91 cases of WD, which included 28 needle biopsies and 64 explants from 14 centers worldwide. Histologic features were evaluated, and a histopathological pattern was assigned to each case. All cases were evaluated with Masson trichrome and MTH IHC (clone UC1MT, Abcam) using a previously published technique. Liver tissues from chronic cholestatic diseases (n = 42) were used as controls. The median age of the cohort was 28.5 years. Of the 91 total cases, 83 were positive for MTH immunostain. In the controls, all 42 cases were negative for MTH immunostain. The sensitivity and specificity of MTH immunostain for WD were 91.20% and 100%, respectively. MTH IHC is a highly sensitive and specific cost-effective screening tool for WD. It can be used for patients across age groups, varied histologic patterns, and fibrosis stages. This marker could prove to be a valuable tool in the evaluation of patients with possible WD.

The Role of Zinc in Developed Countries in Pediatric Patients: A 360-Degree View

Zinc is an important trace element for growth and health at pediatric ages. Zinc is fundamental in inflammatory pathways, oxidative balance, and immune function. Zinc exhibits anti-inflammatory properties by modulating Nuclear Factor-kappa (NF-κB) activity and reducing histamine release from basophils, leukocytes, and mast cells. Furthermore, its antioxidant activity protects against oxidative damage and chronic diseases. Finally, zinc improves the ability to trigger effective immune responses against pathogens by contributing to the maturation of lymphocytes, the production of cytokines, and the regulation of apoptosis. Given these properties, zinc can be considered an adjunctive therapy in treating and preventing respiratory, nephrological, and gastrointestinal diseases, both acute and chronic. This review aims to deepen the role and metabolism of zinc, focusing on the role of supplementation in developed countries in pediatric diseases.

Metallothionein: a game changer in histopathological diagnosis of Wilson disease

AIMS

Wilson disease (WD) is a genetic disorder of copper metabolism caused by mutations in the ATP7B gene. Toxic copper accumulation leads to hepatic, neurologic, and psychiatric disorders with variable presentation. Metallothionein (MT) immunohistochemistry was proposed as a diagnostic marker.

METHODS

MT immunohistochemistry was performed on liver specimens of WD patients (n = 64) and control cases (n = 160) including acute liver failure, steatotic liver disease, autoimmune hepatitis, normal liver, primary biliary cholangitis, primary and secondary sclerosing cholangitis, and progressive familial intrahepatic cholestasis. The optimal cutoff for detection of WD was determined by receiver operating characteristic (ROC) analysis.

RESULTS

At least moderate staining in >50% of hepatocytes was observed in 81% of analysed liver specimens (n = 56/69) of WD patients, while only five control cases showed this staining pattern. The sensitivity, specificity, and accuracy for a new diagnosis of WD were 85.7%, 96.9%, and 94.9%, respectively. Sensitivity in nonfibrotic patients was 70.6% and this MT pattern was robust in small biopsies. The hepatic copper concentration was similar between MT-positive and MT-negative liver samples (P > 0.05). Zinc treatment may induce hepatocellular MT expression. Kayser-Fleischer rings (50% versus 15%) and neurologic disorders (50% versus 13%) were significantly more prevalent in MT-negative compared to MT-positive WD patients, respectively.

CONCLUSION

MT immunostaining is an excellent biomarker for histological diagnosis of WD, should be incorporated in the diagnostic work-up of patients with potential WD, and is useful in a modified Leipzig score.

Molecular Characterization of Esophageal Squamous Cell Carcinoma Using Quantitative Proteomics

Esophageal squamous cell carcinoma (ESCC) is a heterogeneous cancer associated with a poor prognosis in advanced stages. In India, it is the sixth most common cause of cancer-related mortality. In this study, we employed high-resolution mass spectrometry-based quantitative proteomics to characterize the differential protein expression pattern associated with ESCC. We identified several differentially expressed proteins including PDPN, TOP2A, POSTN and MMP2 that were overexpressed in ESCC. In addition, we identified downregulation of esophagus tissue-enriched proteins such as SLURP1, PADI1, CSTA, small proline-rich proteins such as SPRR3, SPRR2A, SPRR1A, KRT4, and KRT13, involved in squamous cell differentiation. We identified several overexpressed proteins mapped to the 3q24-29 chromosomal region, aligning with CNV alterations in this region reported in several published studies. Among these, we identified overexpression of SOX2, TP63, IGF2BP2 and RNF13 that are encoded by genes in the 3q26 region. Functional enrichment analysis revealed proteins involved in cell cycle pathways, DNA replication, spliceosome, and DNA repair pathways. We identified the overexpression of multiple proteins that play a major role in alleviating ER stress, including SYVN1 and SEL1L. The SYVN1/SEL1L complex is an essential part of the ER quality control machinery clearing misfolded proteins from the ER. SYVN1 is an E3 ubiquitin ligase that ubiquitinates ER-resident proteins. Interestingly, there are also other non-canonical substrates of SYVN1 which are known to play a crucial role in tumor progression. Thus, SYVN1 could be a potential therapeutic target in ESCC.

Mitochondrial copper in human genetic disorders

Copper is an essential micronutrient that serves as a cofactor for enzymes involved in diverse physiological processes, including mitochondrial energy generation. Copper enters cells through a dedicated copper transporter and is distributed to intracellular cuproenzymes by copper chaperones. Mitochondria are critical copper-utilizing organelles that harbor an essential cuproenzyme cytochrome c oxidase, which powers energy production. Mutations in copper transporters and chaperones that perturb mitochondrial copper homeostasis result in fatal genetic disorders. Recent studies have uncovered the therapeutic potential of elesclomol, a copper ionophore, for the treatment of copper deficiency disorders such as Menkes disease. Here we review the role of copper in mitochondrial energy metabolism in the context of human diseases and highlight the recent developments in copper therapeutics.