The Authors Reply as Follows

Boscato LM Stuart MC . Incidence and specificity of interference in two-site immunoassays. Clin Chem 1986; 32: 1491–5.

Zweig MH Csako G Interference by anti-immunoglobulin G antibodies in immuno-radiometric assays of thyrotropin involving mouse monoclonal antibodies. Clin Chem 1987; 33: 840–4.

Finlayson J Sneddon W Percy-Robb IW . Interference in commercial assays for thyrotropin. Lancet 1987; i: 445–6.

John R Henley R . Interference with commercial assays for thyrotropin. Lancet 1987; i: 446.

Squire CR Gimlette TMD . Assessment of an enhanced chemiluminescent immunometric assay for TSH in 1127 patients. Ann Clin Biochem 1987; 24: 419–25.