Contrast in cytokine expression between patients with monoclonal gammopathy of undetermined significance or multiple myeloma.
We investigated whether differences in IL-6 and IL-1beta expression could be detected in monoclonal plasma cells from patients with MGUS or MM. Expression of IL-6 and IL-1beta in bone marrow cells was determined using cell sorting to enrich for plasma cells followed by reverse transcriptase/polymerase chain reaction (RT/PCR). Nineteen patients (six MGUS, two primary amyloid (AL), 11 MM) were studied. IL-6 mRNA expression was detectable in the sorted CD38+/CD45- plasma cell populations from 0/6 MGUS, 0/2 AL and 5/11 MM patients. All five MM patients with autocrine IL-6 expression demonstrated an elevated plasma cell labeling index. IL-1beta mRNA was detectable in the sorted CD38+/CD45- plasma cell populations from 1/6 MGUS, 0/2 AL and 10/11 MM patients. In situ hybridization (ISH) confirmed that the IL-1beta producing cells were plasma cells. In conclusion, autocrine production of IL-6 parallels a high labeling index and aberrant expression of IL-1beta correlates with the diagnosis of MM. Follow-up of IL-1beta-positive MGUS patients will determine whether aberrant expression of IL-1beta will predict those MGUS patients that will eventually progress to MM.
Donovan
K A
KA
Division of Hematology and Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA.
Lacy
M Q
MQ
Kline
M P
MP
Ahmann
G J
GJ
Heimbach
J K
JK
Kyle
R A
RA
Lust
J A
JA
D005434:Flow Cytometry; D006801:Humans; D017403:In Situ Hybridization; D007375:Interleukin-1 / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000096:biosynthesis*; D009101:Multiple Myeloma / Q000378:metabolism*; D010265:Paraproteinemias / Q000378:metabolism*; D010950:Plasma Cells / Q000378:metabolism; D016133:Polymerase Chain Reaction; D014158:Transcription, Genetic
D007375:Interleukin-1; D015850:Interleukin-6