Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Ferritin and Hemochromatosis Polymorphisms Correlate with Clinical Characteristics in a Symptomatic Osteoarthritis Cohort.

Kennish1,  Lauren M., Attur2,  Mukundan, Huang3,  Xi, Krasnokutsky4,  Svetlana, Samuels2,  Jonathan, Oh5,  Cheongeun, Abramson2,  Steven B.

Hospital for Joint Diseases, New York, NY
NYU Hospital for Joint Diseases, New York, NY
New York University School of Medicine, New York, NY
NYU Hospital for Joint Disease, New York, NY
New York University, New York, NY

Background/Purpose:

Iron may be a contributing risk factor for osteoarthritis (OA) development – increased iron is found in OA synovial fluid and is cytotoxic towards chondrocytes. Additionally, patients with hereditary hemochromatosis develop an OA phenotype that is associated with higher ferritin levels. We examined the hypothesis that serum ferritin correlates with clinical features in patients with symptomatic knee OA compared to controls and that this may be associated with hemochromatosis gene (HFE) polymorphisms.

Methods:

131 patients with symptomatic knee OA (diagnosed by ACR criteria, WOMAC score>125) and 21 controls were enrolled in a 2 year longitudinal study. Patients with inflammatory arthritis, infections, steroid use or major comorbid illnesses were excluded. Baseline clinical (age, gender, BMI, WOMAC pain score) and radiographic characteristics (Kellgren-Lawrence, KL, score) were obtained. Cross sectional peripheral blood samples were analyzed for serum ferritin at baseline and 18months by ELISA. HFE genotyping was performed.

Results:

Ferritin was measured in 131 OA patients with mean age 65 years (35% men), BMI 26.5 and 20 controls with mean age 56 years (55% men), and BMI 26.5. Men were found to have higher ferritin than women – 62.5 vs. 38.2 ng/ml, p=0.0002, and ferritin correlated with increasing age (r=0.175, p=0.058). Men with OA had a trend towards higher mean ferritin than those without OA when adjusted for age (67.7 vs. 40.4ng/ml, p=0.068). In the total population, ferritin levels greater than 100ng/ml were observed in 13% of patients with OA versus 0% of controls. There was a trend towards higher ferritin in patients with baseline radiographic incidence of OA (KL 0–1: 42.3 vs. KL 2–4: 63.3ng/ml, p=0.276) and in those with more severe radiographic OA (KL 1–2: 48.1 vs. KL 3–4: 71.3ng/ml, p = 0.236). Those with a higher KL score ranging from 0 to 3 were found to have higher serum ferritin, which may be predictive of severity of OA. Baseline WOMAC pain scores in the total OA population showed a weak positive correlation with serum ferritin levels (r= 0.112, p = 0.0148); this positive correlation between WOMAC pain and ferritin was stronger in males (r=0.215, p = 0.008). OA patients had a higher frequency of homozygous HFE gene polymorphism C282Y/C282Y (2.29%) compared to controls (0%) and published population controls (0.44%), and these subjects (n=3) had higher ferritin compared to wild type (n=98) (47.4 vs 140.1ng/ml, p<0.0008).

Conclusion:

Ferritin, a marker for body iron storage, increases with age and male gender. Men with OA exhibit higher ferritin levels than those without OA when adjusted for age and levels of ferritin correlated with radiographic severity and WOMAC pain scores. In selected OA patients, the presence of the C282Y/C282Y HFE gene polymorphism was associated with higher ferritin levels. Our data suggest that increased ferritin levels, possibly in part due to HFE polymorphisms, may promote cartilage damage and pain in patients with knee OA. These findings merit further investigation of ferritin as a biomarker of disease severity and progression in a larger cohort.

To cite this abstract, please use the following information:
Kennish, Lauren M., Attur, Mukundan, Huang, Xi, Krasnokutsky, Svetlana, Samuels, Jonathan, Oh, Cheongeun, et al; Ferritin and Hemochromatosis Polymorphisms Correlate with Clinical Characteristics in a Symptomatic Osteoarthritis Cohort. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :171
DOI:

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