Plasma cell disorders

Plasma cell disorders, also called plasma cell dyscrasias, refer to a group of hematological disorders involving plasma cells (a type of B cell). In these conditions, plasma cells secrete an abnormal antibody called a monoclonal (or myeloma) protein, or M protein. The presence of this abnormal antibody is called monoclonal gammopathy. [1] Three major plasma cell disorders for which hematopoietic cell transplantation (HCT) may be indicated are multiple myeloma, light chain amyloidosis and POEMS syndrome (osteosclerotic myeloma).

Multiple myeloma (MM) affects about 36,000 people in the United States annually, with a median age at diagnosis of 69 years. [2] It is the most common indication for HCT in the United States. Most patients with MM who undergo HCT receive an autologous transplant. [3]

Allogeneic HCT for MM is generally reserved for patients with high-risk disease. Most allogeneic transplants are performed after an autologous transplant with reduced-intensity or non-myeloablative conditioning regimens. [4] Since 2021, the use of chimeric antigen receptor T-cell (CAR-T) therapy for treatment of MM has steadily increased. [3]

• At diagnosis
• At progression and/or relapse

Light chain amyloidosis, also known as AL amyloidosis or primary amyloidosis, involves the overproduction of abnormal light chain proteins, which deposit on organs instead of forming immunoglobins. Although not considered a malignancy, light chain amyloidosis shares features with multiple myeloma. [5] Autologous HCT in amyloidosis has shown improved post-transplantation survival, including both early post-transplant mortality and 5-year survival. [6]

• At diagnosis
• At progression and/or relapse

POEMS syndrome involves a cluster of symptoms: polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes. It is also characterized by sclerotic or lytic bone lesions. [1] Autologous HCT and high-dose chemotherapy are both treatment options for POEMS syndrome, but longer follow-up is needed to better determine overall survival. [7]

• At diagnosis

1. National Cancer Institute: Plasma cell neoplasms (including multiple myeloma) treatment (PDQ^®)–health professional version. Accessed July 9, 2025. Access
2. SEER: Cancer stat facts: myeloma. Accessed July 9, 2025. Access
3. Spellman, SR, Xu S, Oloyede T, et al. Current activity trends and outcomes in hematopoietic cell transplantation and cellular therapy—a report from the CIBMTR. Transplantation and Cellular Therapy. 2025, ISSN 2666-6367. Access
4. Kyle RA, Rajkumar SV. Multiple myeloma. Blood. 2008;111(6):2962-2972. Access
5. Baker KR. Light chain amyloidosis: epidemiology, staging, and prognostication. Methodist Debakey Cardiovasc J. 2022;18(2):27–35. Access
6. D'Souza A, Dispenzieri A, Wirk B, et al. Improved outcomes after autologous hematopoietic cell transplantation for light chain amyloidosis: a Center for International Blood and Marrow Transplant Research study. Journal of Clinical Oncology. 2015;33(32):3741-3749. Access
7. D'Souza A, Lacy M, Gertz M, et al. Long-term outcomes after autologous stem cell transplantation for patients with POEMS syndrome (osteosclerotic myeloma): a single-center experience. Blood. 2012;120(1):56-62. Access
8. National Comprehensive Cancer Network. Multiple myeloma. (Version 3.2023). Access
9. National Comprehensive Cancer Network. Systemic light chain amyloidosis. (Version 1.2026). Access
10. NMDP and ASTCT Recommended Timing for Transplant Consultation. Download PDF