Serum interleukin-6 levels correlate with prognosis in diffuse large-cell lymphoma.
OBJECTIVE
Interleukin-6 (IL-6) is a potent immunomodulatory cytokine that may have pathogenetic and prognostic significance in a number of disorders. The objective of this study was to examine the correlation between serum IL-6 levels and phenotypic characteristics, as well as outcome of patients with diffuse large-cell lymphoma (DLCL).


METHODS
Using an enzyme-linked immunosorbent assay (ELISA; lower limit of sensitivity, 0.35 pg/mL), we measured IL-6 levels in frozen sera from 33 healthy controls and 58 untreated patients with DLCL who were enrolled onto a single combination chemotherapy protocol. Serum IL-6 levels were correlated with clinical and laboratory features at diagnosis and with failure-free and overall survival.


RESULTS
Serum IL-6 levels in the lymphoma patients (median, 4.37 pg/mL; range, < 0.35 to 110 pg/mL) were significantly higher than in the control group (median, < 0.35 pg/mL; range, < 0.35 to 1.87 pg/mL) (P < .0001). Serum IL-6 levels were higher in patients with B symptoms (P = .012), an elevated beta 2-microglobulin level (> or = 3.0 mg/L) (P = .017), and a poor performance status (P = .02). Direct linear correlations with the erythrocyte sedimentation rate (ESR), platelet count, and total WBC count, and an inverse linear correlation with the serum albumin level, were observed (all P < .02). Patients with elevated serum IL-6 levels had inferior failure-free (P = .042) and overall survival (P = .05) compared with those with normal serum IL-6 levels.


CONCLUSIONS
In patients with DLCL, elevated serum levels of IL-6 at diagnosis are frequent, strongly associated with many adverse disease features, and predictive of a poor failure-free and overall survival.
Seymour
J F
JF
Department of Clinical Investigation, M.D. Anderson Cancer Center, Houston, TX 77030.
Talpaz
M
M
Cabanillas
F
F
Wetzler
M
M
Kurzrock
R
R
D000328:Adult; D000368:Aged; D001799:Blood Sedimentation; D018572:Disease-Free Survival; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D016018:Least-Squares Analysis; D007958:Leukocyte Count; D016403:Lymphoma, Large B-Cell, Diffuse / Q000097:blood / Q000276:immunology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011379:Prognosis; D012044:Regression Analysis; D012709:Serum Albumin / Q000378:metabolism; D015996:Survival Rate; D001613:beta 2-Microglobulin / Q000378:metabolism
D015850:Interleukin-6; D012709:Serum Albumin; D001613:beta 2-Microglobulin