Role of UGT1A1 and ADH gene polymorphisms in pegvisomant-induced liver toxicity in acromegalic patients

Hepatotoxicity is one of the most serious adverse effects in acromegalic patients treated with pegvisomant (PEG-V). Recent studies have found an association between this adverse event and the UGT1A1 allele 28 polymorphism associated with Gilbert's syndrome.

To determine whether UGT1A1*28 and alcohol dehydrogenase (ADH) polymorphisms influence liver toxicity during PEG-V treatment.

Multicenter observational retrospective study conducted in 13 tertiary care endocrinology units in Italy.

A total of 112 patients with active disease resistant to somatostatin analogs (SSTa) and 108 controls were enrolled.

Clinical and biochemical data were recorded by electronic clinical reporting forms. Blood or DNA samples were sent to the coordinating center for genotyping.

No differences in genotypes between patients and controls were found. During PEG-V therapy liver function tests (LFT), abnormalities and overt hepatotoxicity developed in 17 and 4.5% of patients respectively. Logistic and linear regression analyses showed an association between LFT abnormalities during the follow-up visit and prior events of LFT abnormalities in medical history (odds ratio=1.25; P=0.04) and the number of concomitant medications, other than SSTa (B=3.9; P=0.03). No correlation between LFT alterations and UGT1A1 allele 28 as well as ADH1C and B polymorphisms was found.

UGT1A1 allele 28 and ADH1C and B polymorphisms do not predict increased risk of hepatotoxicity during PEG-V therapy. Conversely, patients with multi-therapies and with previous episodes of liver disease should be carefully managed, due to the observed association between these conditions and LFT abnormalities during PEG-V therapy.