Serologically, 11 of 19 patients with PPK (58%) had kappa-restricted plasma cell dyscrasia (7 with IgG, 2 with IgA and 2 with light-chain only), and 8 of 19 patients (42%) had lambda-restricted plasma cell dyscrasia (1 with IgG, 4 with IgA, 1 with both IgG and IgA and 2 with light-chain only). Here, CD79A is linked to dysplasia.