J chain disease: an aggressive evolution of multiple myeloma

Broadly applicable TCR-based therapy for multiple myeloma targeting the immunoglobulin J chain

BACKGROUND

The immunoglobulin J chain (Jchain) is highly expressed in the majority of multiple myeloma (MM), and Jchain-derived peptides presented in HLA molecules may be suitable antigens for T-cell therapy of MM.

METHODS

Using immunopeptidomics, we identified Jchain-derived epitopes presented by MM cells, and pHLA tetramer technology was used to isolate Jchain-specific T-cell clones.

RESULTS

We identified T cells specific for Jchain peptides presented in HLA-A1, -A24, -A3, and -A11 that recognized and lysed JCHAIN-positive MM cells. TCRs of the most promising T-cell clones were sequenced, cloned into retroviral vectors, and transferred to CD8 T cells. Jchain TCR T cells recognized target cells when JCHAIN and the appropriate HLA restriction alleles were expressed, while JCHAIN or HLA-negative cells, including healthy subsets, were not recognized. Patient-derived JCHAIN-positive MM samples were also lysed by Jchain TCR T cells. In a preclinical in vivo model for established MM, Jchain-A1, -A24, -A3, and -A11 TCR T cells strongly eradicated MM cells, which resulted in 100-fold lower tumor burden in Jchain TCR versus control-treated mice.

CONCLUSIONS

We identified TCRs targeting Jchain-derived peptides presented in four common HLA alleles. All four TCRs demonstrated potent preclinical anti-myeloma activity, encouraging further preclinical testing and ultimately clinical development.

Complex IgA gammopathy in Gaucher's disease

A 55-year-old Jewish patient was simultaneously diagnosed as having Gaucher's disease and IgA multiple myeloma. Serum protein electrophoresis and immunoelectrophoresis showed two different IgA kappa type monoclonal spikes. After four years of observation, a rapid fatal course of disease developed together with expression of J chain protein and an additional IgA lambda paraprotein. Although dysproteinaemias and multiple myeloma have occasionally been reported in Gaucher's patients, such a complex gammopathy has to the best of our knowledge not yet been described.

Anaplastic myeloma

Anaplastic myeloma (AM) represents a rare variety of multiple myeloma (MM) with poor prognosis. One case with special interest is reported, which presented with manifestations due to the extramedullary localization and arose in the absence of an initial diagnosis of MM. In addition, differential diagnosis was based on morphological and immunocytochemical findings while treatment with radio-chemotherapy had no effect on the extramedullary sites.

Ultrastructure of plasma cells in a patient with J chain disease

Ultrastructural analysis of plasma cells was performed in a 74-year-old female patient with J chain disease. By electron microscopy, various characteristic findings were observed: lobulated nuclei, multinuclei, single sac loop-like structures, flocculent filament-like substances, nuclear inclusion bodies, cytoplasmic inclusion bodies, and multilamellar bodies. Our prior studies pointed out a poor prognosis in myeloma patients with these findings.

Change of paraprotein from IgG lambda to lambda chain in myeloma

We describe a unique case of IgG lambda myeloma in which a plasma cell leukemia developed and the paraprotein changed from IgG lambda to lambda chain, the latter inducing fatal renal failure. In addition, J-chain was detected in the cytoplasm of the plasma cell leukemia cells.