Needle liver biopsy in thalassaemia: analyses of diagnostic accuracy and safety in 1184 consecutive biopsies

We report the reliability and safety of percutaneous liver biopsy in the evaluation of hepatic iron loading and histology in patients with homozygous β-thalassaemia prior to and in serial biopsies following allogeneic bone marrow transplantation for this disorder. 501 thalassaemic patients aged 11 ± 4.5 years (range 1-32 years) underwent 1184 consecutive percutaneous liver biopsies without ultrasound guidance. Overall, 81% of biopsies were evaluable for histological examination and grading of iron. The adequacy of liver biopsy specimens increased with patient age: evaluable specimens were obtained in 73% of patients <5 years of age and in 86% of samples in patients aged >15 years. The degree of iron overload and fibrosis in each biopsy was reported separately by at least two pathologists who did not know the clinical status of each patient. In 103 biopsies, iron grade by light microscopy corresponded to an iron concentration varying between a mean of 32.46 ± 14 μmol/g dry weight liver tissue for iron stores graded by light microscopy as absent to 417.6 ± 150μmol/g dry weight liver tissue for stores graded as severe. The fibrosis score of multiple samples of liver obtained at autopsy within 100 d of the percutaneous biopsy in 41 patients who died following BMT correlated perfectly with that of the first sample in >60% biopsies; in most of the discordant cases fibrosis had been underestimated in the percutaneous biopsy. Liver biopsy demonstrated evidence of chronic hepatitis in 30% of patients with normal transaminase and in 57% of patients with transaminase within twice the normal range. Liver biopsy was complicated in six patients (0.5%) by haemoperitoneum, periocholecystic haematoma, kidney haematoma, or bile peritonitis; no complication was fatal. These data demonstrate that percutaneous liver biopsy provides reliable information regarding liver iron and histology in homozygous β-thalassaemia with an extremely low risk of complications.