Clinical relevance of persistently elevated circulating cytokines (tumor necrosis factor alpha and interleukin-6) in the long-term followup of patients with giant cell arteritis.
OBJECTIVE
To assess the clinical relevance of increased circulating cytokines in patients with giant cell arteritis (GCA) after long-term followup.


METHODS
We performed a cross-sectional evaluation of 54 patients with biopsy-proven GCA prospectively followed for a median of 5.4 years (range 4-10.5 years). GCA-related complications, vascular events, relapses, current prednisone dose, time required to achieve a maintenance prednisone dosage <10 mg/day, cumulated prednisone at that point, and adverse effects during followup were recorded. Serum interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFalpha) were determined by immunoassay.


RESULTS
All patients were in clinical remission. Both cytokines were significantly higher in patients than in controls (mean +/- SD 21 +/- 35 versus 5 +/- 11 pg/ml; P < 0.001 for IL-6 and mean +/- SD 32 +/- 14 versus 16 +/- 9 pg/ml; P < 0.001 for TNFalpha). No differences were found in patients with or without GCA-related complications or vascular events during followup. Circulating cytokines were significantly higher in patients who had experienced relapses (mean +/- SD 25 +/- 39 versus 10 +/- 11 pg/ml; P = 0.04 for IL-6 and mean +/- SD 34 +/- 15 versus 25 +/- 11 pg/ml; P = 0.042 for TNFalpha). IL-6 was significantly higher in patients still requiring prednisone (mean +/- SD 29 +/- 45 versus 13 +/- 17 pg/ml; P = 0.008), and TNFalpha correlated with cumulated prednisone dose (r = 0.292, P = 0.04). No significant relationship was found between elevated cytokines and prednisone adverse effects or patients' quality of life.


CONCLUSIONS
Circulating TNFalpha and IL-6 may persist elevated in GCA patients after long-term followup and remain higher in patients who have experienced more relapsing disease. However, in this patient cohort, elevated circulating cytokines were not associated with increased frequency of GCA complications, vascular events, or treatment-related side effects.
Hospital Clínic, University of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
Ana
A
García-Martínez
José
J
Hernández-Rodríguez
Georgina
G
Espígol-Frigolé
Sergio
S
Prieto-González
Montserrat
M
Butjosa
Marta
M
Segarra
Ester
E
Lozano
Maria C
MC
Cid
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D013700:Giant Cell Arteritis / Q000097:blood* / Q000175:diagnosis; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
D015415:Biomarkers; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha