Figure 2.

Maturation of four immunoglobulin G (IgG)‐producing B‐cell clones from two multiple sclerosis (MS) patients. High‐throughput sequencing of immunoglobulin heavy‐chain variable (IGHV) transcripts from cerebrospinal fluid (CSF) and blood was performed, and IgG from CSF and serum was analyzed by mass spectrometry. Each node represents a single IGHV sequence. The hypothetical germline (GL) sequence is set as origo, and the connecting lines depict somatic mutations. Lines without numbers denotes a single‐nucleotide exchange, “2” denotes two mutations, and so on. Gray nodes represent sequences only detected in CSF, the red node is a sequence only detected in blood, and blue nodes are identical sequences detected in both CSF and blood, whereas white nodes represent hypothetical intermediates. Larger nodes represent the most abundant transcripts. The CDR3 of all lineage trees matched CSF IgG. The rightmost tree of MS‐1 also matched IgG from serum.