Fig. 1.

aIgA1 binding to HMC. Equilibrium binding of 125 I-aIgA1 to cultured HMC was assessed at 4°C as described in the Methods section. The experiment with triplicate wells was repeated three times in the study. The inset is a Scatchard plot. The cells were a mixture of six lines and the aIgA1 sample was from pooled sera of 10 healthy controls or 10 patients. P = 0·026, Kd value of 8·89 ± 2·1 ×10⁻⁸m for Pat. aIgA1 (patient's aIgA1) versus (4·3 ± 1·2 × 10⁻⁷m for Nor. aIgA1 (normal aIgA1).