igg kappa myelomaigg kappa light chain multiple myelomaigg kappa smoldering myelomastage iii igg kappa multiple myelomaigg lambda multiple myelomamultiple myeloma igg lambda typeigg lambda myelomaigg kappa mmigg multiple myelomaigg kappa monoclonaligg kappa monoclonal protein detectedmultiple myeloma kappa lambda ratio