People without evidence of a monoclonal protein may have "nonsecretory" myeloma (not producing immunoglobulins); this represents about 3% of all people with multiple myeloma.Additional findings may include a raised calcium level (when osteoclasts are breaking down bone, releasing it into the bloodstream), raised serum creatinine level due to reduced kidney function, which is mainly due to casts of paraprotein deposition in the kidney, although the cast may also contain complete immunoglobulins, Tamm-Horsfall protein and albumin.Other useful laboratory tests include quantitative measurement of IgA, IgG, and IgM to look for immune paresis, and beta-2 microglobulin, which provides prognostic information. On peripheral blood smear, the rouleaux formation of red blood cells is commonly seen, though this is not specific. The recent introduction of a commercial immunoassay for measurement of free light chains potentially offers an improvement in monitoring disease progression and response to treatment, particularly where the paraprotein is difficult to measure accurately by electrophoresis (for example in light chain myeloma, or where the paraprotein level is very low). Initial research also suggests that measurement of free light chains may also be used, in conjunction with other markers, for assessment of the risk of progression from MGUS to multiple myeloma.This assay, the serum free light chain assay, has recently been recommended by the International Myeloma Working Group for the screening, diagnosis, prognosis, and monitoring of plasma cell dyscrasias. Histopathology
A bone marrow biopsy is usually performed to estimate the percentage of bone marrow occupied by plasma cells. This percentage is used in the diagnostic criteria for myeloma.
ixazomib—an orally available proteasome inhibitor indicated in combination with lenalidomide and dexamethasone in people who have received at least one prior therapy
panobinostat—an orally available histone deacetylase inhibitor used in combination with bortezomib and dexamethasone in people who have received at least two prior chemotherapy regimens, including bortezomib and an immunomodulatory agent
selinexor—an orally available selective inhibitor of nuclear export indicated in combination with dexamethasone in people who have received at least four prior therapies and whose disease does not respond to at least two proteasome inhibitors, two immunomodulatory agents and an anti-CD38 monoclonal antibody
idecabtagene vicleucel—first cell-based gene therapy was approved by FDA in 2021 for the treatment of adults with relapsed or refractory multiple myeloma who have received at least four prior therapies

Stem cell transplant
Stem cell transplant can be used to treat multiple myeloma. Stem cell transplants come with a risk of a graft-versus-host-disease. Mesenchymal stromal cells may reduce the all-cause mortality if they are used for a therapeutic reason and the therapeutic use of MSCs may increase the complete response of acute and chronic GvHD, but the evidence is very uncertain. The evidence suggests that MSCs for prophylactic reason result in little to no difference in the all-cause mortality, in the relapse of malignant diseases and in the incidence of acute GvHD. The evidence suggests that MSCs for prophylactic reason reduce the incidence of chronic GvHD.