CD79A and in situ carcinoma: Intrathecal IgM and IgA synthesis were also more frequent in the MS group (IgM 35%, IgA 8%) compared to the CIS group (IgM 7%, IgA 1%) (IgM p =  < 0.0001, OR: 6.7, 95% CI 2.99–15; IgA p = 0.0132, OR: 8.99, 95% CI 1.13–71.45).