Submitted April 29, 2008
Accepted November 18, 2008
Splenic plasma cells can serve as a source of amyloidogenic light chains
Alan Solomon*, Sallie D. Macy, Craig Wooliver, Deborah T. Weiss, and Per Westermark
The Human Immunology and Cancer Program, Department of Medicine, University of Tennessee Graduate School of Medicine, Knoxville, TN, United States
Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden
* Corresponding author; email: asolomon{at}utmck.edu.
Bone marrow-derived clonal plasma cells, as found in systemic AL amyloidosis, are presumed to be the source of light chains that deposit as fibrils in tissues throughout the body. Paradoxically, individuals with this disorder, in contrast to multiple myeloma, often have a low percentage of such cells and it is unknown if this relatively sparse number can synthesize enough amyloidogenic precursor to form the extensive pathology that occurs. To investigate if another hematopoietic organ - the spleen - also contains monoclonal light chain-producing plasma cells, we have immunostained such tissue from 26 AL patients using anti-plasma cell, anti-free 
and 
, and anti-VL subgroup-specific mAbs. In 12 cases, there was statistically significant evidence of a monoclonal population bearing the same or isotype as that within the bone marrow and identical to the amyloid. Our studies have shown that the spleen may be another source of amyloidogenic light chains.
