Two New Considerations for Improving the Diagnosis of α1-Antitrypsin Deficiency-Associated Liver Disease

A Review on Clinical, Pathophysiological, and Diagnostic Hematological Features in Children With Liver Cirrhosis

Appropriate diagnostic and therapeutic measures for liver cirrhosis is critical, particularly in children. In the present review, a comprehensive approach was provided toward hematological parameters in pediatric liver cirrhosis. The literature search included MeSH terms "liver cirrhosis" and "hepatic cirrhosis" and databases such as PubMed, Web of Science, Scopus, and Google Scholar were searched up until December 2017. Hematologic changes in the liver cirrhosis mainly encompassed anemia and coagulopathies. In addition, bleeding diathesis was considered as the most clinical complication in these patients. In addition to reduced coagulation factors, hyperfibrinolysis is a common feature in childhood cirrhosis and may be an important contributor to the risk of bleeding. Based on the results, children with liver cirrhosis also demonstrated a procoagulant state at laboratory and clinical levels. This may be partly due to a reduction in coagulation inhibitors such as anti-thrombin, C1 inhibitor, and α1-antitrypsin in children with cirrhosis. The portal vein thrombosis and portal hypertension are considered as the most clinical presentations of the hypercoagulable state. Further, children with liver cirrhosis complicated with portal hypertension usually show leukopenia, anemia, and thrombocytopenia due to hypersplenism. Although the etiology of childhood and adult cirrhosis may be different, their hematological compilations and clinicopathological features are somehow similar.

Retrospective analysis of children with α-1 antitrypsin deficiency

BACKGROUND

α-1 Antitrypsin (AAT) deficiency is the most frequently occurring genetic liver disorder. The association among classical α-1 antitrypsin deficiency (AATD), chronic liver disease, and cirrhosis is common in adult patients but rare in children.

AIM

To assess the clinical characteristics of children with AATD and to compare symptoms between homozygous and heterozygous children.

MATERIALS AND METHODS

The study included 20 children who were found to have mutant Pi alleles. AAT phenotyping was conducted on patients with a low serum AAT level. The exclusion criteria included infectious, anatomic, and metabolic conditions. Symptoms on presentation, physical examination findings, laboratory values, liver biopsy results, and follow-up periods were recorded for each patient.

RESULTS

The patients included six (30%) girls and 14 (70%) boys, with a mean age of 6.3±5.1 (1-16) years. The PiZZ phenotype was present in eight (40%) and PiMZ in 12 (60%) patients. The most frequent symptom was elevated liver function test results. Three patients were referred with neonatal cholestasis and one with compensated cirrhosis. Eight patients underwent liver biopsy; all patients except one had periodic acid-Schiff-positive diastase-resistant globules in the hepatocytes. The mean follow-up period was 34±33 (12-101) months. At the end of follow-up, all patients with PiZZ were found to have chronic hepatitis, and one with cirrhosis. On the contrary, two patients with PiMZ were found to have chronic hepatitis.

CONCLUSION

Children with classical AATD commonly have chronic liver disease. In heterozygous (PiMZ) children with AATD, enzyme levels can normalize with occasional fluctuations, sometimes causing delayed diagnosis.

Liver Disease in Alpha-1 Antitrypsin Deficiency: Current Approaches and Future Directions

Purpose of Review

The aim of the study is to review the liver disease caused by alpha-1 antitrypsin deficiency (A1ATD), including pathogenesis, epidemiology, diagnostic testing, and recent therapeutic developments.

Recent Findings

Therapeutic approaches target several intracellular pathways to reduce the cytotoxic effects of the misfolded mutant globular protein (ATZ) on the hepatocyte. These include promoting ATZ transport out of the endoplasmic reticulum (ER), enhancing ATZ degradation, and preventing ATZ globule-aggregation.

Summary

A1ATD is the leading genetic cause of liver disease among children. It is a protein-folding disorder in which toxic insoluble ATZ proteins aggregate in the ER of hepatocytes leading to inflammation, fibrosis, cirrhosis, and increased risk of hepatocellular carcinoma. The absence of the normal A1AT serum protein also predisposes patients to pan lobar emphysema as adults. At this time, the only approved therapy for A1ATD-associated liver disease is orthotopic liver transplantation, which is curative. However, there has been significant recent progress in the development of small molecule therapies with potential both to preserve the native liver and prevent hepatotoxicity.