Résumé
A 54-year-old man presented with protein-losing enteropathy. Biopsies from the stomach, duodenum, ileum and colon showed deposits of amyloid. The bone marrow showed plasmacytosis. After an initial misdiagnosis of AA amyloid, a revised diagnosis of ALκ amyloidosis was made at an expert referral laboratory. Care must be taken in the use of antibodies and proper controls in the performance and interpretation of immunohistochemistry for amyloidosis. A wide panel of amyloid-type-specific antibodies must be used and interpreted in comparative mode to avoid misdiagnosis. Natl Med J India 2015;28:129–31
Résumé
BACKGROUND: Serological tests may fail to identify hepatitis B virus (HBV) infection as a cause of liver cirrhosis in a proportion of patients. The frequency of such occult infection in regions with intermediate HBV endemicity is not known. Such cases may be diagnosed by incremental testing for IgG anti-HBc, serum HBV DNA, and HBV DNA in liver tissue. METHODS: We tested sera of 111 patients with cirrhosis, including 39 with history of significant alcohol ingestion, for HBsAg, anti-HBc and serum HBV DNA. In addition, in a subset of 14 patients, HBV DNA was looked for in liver tissue. RESULTS: On HBsAg and anti-HBc testing, 66 patients had HBV infection. Serum HBV DNA testing identified HBV infection in 13 additional cases. Of 18 patients labeled as 'cryptogenic' on serological testing, HBV DNA was detected in the serum in 7 patients. Of 14 patients in whom paired liver tissue and serum specimens were tested, 4 additional patients with HBV infection were detected after liver biopsy analysis. CONCLUSIONS: Serological tests for HBsAg and anti-HBc antibody are insensitive in identifying HBV infection in patients with liver cirrhosis. HBV DNA testing in serum and liver can help in establishing HBV infection as etiology, either alone or in addition to another cause.