Triiodothyronine level and triiodothyronine/thyroxine ratio in HBeAg-positive chronic hepatitis patients treated with prednisolone withdrawal

Molecular functions of thyroid hormones and their clinical significance in liver-related diseases

Thyroid hormones (THs) are potent mediators of several physiological processes, including embryonic development, cellular differentiation, metabolism, and cell growth. Triiodothyronine (T3) is the most biologically active TH form. Thyroid hormone receptors (TRs) belong to the nuclear receptor superfamily and mediate the biological functions of T3 via transcriptional regulation. TRs generally form heterodimers with the retinoid X receptor (RXR) and regulate target genes upon T3 stimulation. Research over the past few decades has revealed that disruption of cellular TH signaling triggers chronic liver diseases, including alcoholic or nonalcoholic fatty liver disease and hepatocellular carcinoma (HCC). Animal model experiments and epidemiologic studies to date imply close associations between high TH levels and prevention of liver disease. Moreover, several investigations spanning four decades have reported the therapeutic potential of T3 analogs in lowering lipids, preventing chronic liver disease, and as anticancer agents. Thus, elucidating downstream genes/signaling pathways and molecular mechanisms of TH actions is critical for the treatment of significant public health issues. Here, we have reviewed recent studies focusing on the roles of THs and TRs in several disorders, in particular, liver diseases. We also discuss the potential therapeutic applications of THs and underlying molecular mechanisms.

Bullous pemphigoid in an HB virus carrier: interaction between corticosteroids and HB virus

A case of bullous pemphigoid (BP) in a 47-year-old female hepatitis B virus (HBV) carrier is reported. Disseminated bullae covered the patient's entire body including the hands and feet. BP was diagnosed on the basis of pathological and immunological observations examining immunofluorescence and cross reactions to both bullous pemphigoid antigen (BPAG) 1 and BPAG 2. Although oral prednisolone (80 mg daily) rapidly healed the eruption, liver function failed to respond, resulting in the patient's death. This liver dysfunction was attributed to the HBV infection. Use of the polymerase chain reaction showed that HBV in this case had transformed into its precore mutation form during the therapy. Standard tests on first examination did not detect HBV in this patient, but later detailed analysis suggested that she had been an HBV carrier since birth. Such carriers sometimes test negative for HBs antigen, when only a little HBV is present in the liver. Great care should also be exercised when using high doses of corticosteroids to treat bullous diseases in HBV carriers, because these drugs may aggravate HBV infections and cause liver failure.

Severe clinical rebound upon withdrawal of corticosteroid before interferon therapy: incidence and risk factors

To analyse the incidence and risk factors of clinical rebound and hepatic decompensation during or upon withdrawal of prednisolone pretreatment before interferon (IFN) therapy, two series of Taiwanese patients with chronic viral hepatitis from two independent randomized controlled trails were compared. Group 1 included 41 patients with chronic hepatitis B who were pretreated with daily prednisolone (30 mg) for 3 weeks, 15 mg for 1 week and no prednisolone for 2 weeks prior to lymphoblastoid IFN therapy. Group 2 consisted of 59 patients with chronic hepatitis B who were pretreated with daily prednisolone (40 mg) for 2 weeks, 30 mg prednisolone for 2 weeks, 20 mg prednisolone for 2 weeks and no prednisolone for 2 weeks prior to INF alpha-2a therapy. Clinical rebound developed more frequently in group 2 (67.8%) than in group 1 patients (41.5%; P < 0.01). The peak serum transaminase levels of group 1 and 2 patients during clinical rebound were similar. Icteric and symptomatic clinical rebound occurred in four (one cirrhotic) group 2 patients. The incidence of hepatic decompensation was 3.4% in group 2 patients, or 5.0% in group 2 patients with clinical rebound. Patients pretreated with a higher dose (40 mg) of prednisolone (odds ratio 3.0; 95% CI 1.3-6.6; P < 0.01) and non-cirrhotic patients (odds ratio 6.2; 95% CI 1.2-32.1; P < 0.02) tended to suffer from clinical rebound more frequently. However, once clinical rebound develops in cirrhotic patients, the relative risk of decompensation is 16 times that of non-cirrhotic patients. These results suggest that clinicians should be cautious in prescribing a short course of corticosteroids for patients with chronic viral hepatitis, because hepatic decompensation might occur in Oriental people with or without cirrhosis.