RESEARCH - Low frequency of anti-CCP antibodies in psoriatic arthritis but not in cutaneous psoriasis

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J Clin Rheumatol. 2006 Oct;12(5):226-9.

Low frequency of anticyclic citrullinated peptide antibodies in psoriatic

arthritis but not in cutaneous psoriasis.

Rheumatology Section, Department of Medicine and the Stanley S. Cancer

Center, LSU Health Sciences Center, New Orleans, Louisiana, USA.

lilicazu@...

BACKGROUND: Anticyclic citrullinated peptide (anti-CCP) antibodies are

highly specific for the diagnosis of rheumatoid arthritis (RA). The clinical

distinction between RA and psoriatic arthritis (PsA) is often difficult to

establish; therefore, the presence of rheumatoid factor (RF) and anti-CCP

antibodies could be useful. Seven percent to 40% of patients with

longstanding psoriasis will develop PsA at some point. Therefore, it is

important to study the positivity of these antibodies in these two

interrelated populations. OBJECTIVE: The aim of this study was to determine

the seropositivity of anti-CCP antibodies in patients with psoriasis and PsA

and to compare it with that seen in patients with other inflammatory,

noninflammatory (osteoarthritis) arthritides and healthy controls. PATIENTS

AND METHODS: Serum anti-CCP antibodies were measured in 106 patients with

cutaneous psoriasis, 72 patients with PsA, 41 healthy controls (HC), 41

patients with undifferentiated or early inflammatory arthritis (UA), and 41

patients with RA and 41 with osteoarthritis using a commercial

second-generation enzyme-linked immunosorbent assay. We considered a

positive result to be >20 UI/mL, as recommended by the manufacturer.

RESULTS: Of 106 patients with PsA, 55 were women and 51 men. The mean age

was 42.87 +/- 17.71 years and the mean disease duration was 5.3 +/- 2.10

years. Anti-CCP antibodies were not present in patients with psoriasis

without arthritis. In contrast, 7 of 72 (9.72%) patients with PsA were

positive for anti-CCP antibodies with a median titer of 7.16 units. Only one

patient with PsA was positive for RF. Most of these patients were female

with polyarticular joint involvement. Distal interphalangeal involvement was

present in 4 and 2 had dactylitis. We found clear differences when we

compared patients with PsA with patients with psoriasis (P = 0.001). Of the

43 patients with UA studies, 4 initially exhibited a low titer positive

anti-CCP antibody, and at follow up, another patient developed anti-CCP

antibodies and later developed RA. None of the patients with UA developed

PsA at 5-year follow up. Thirty-two of the 41 patients had a positive

anti-CCP antibody and the mean +/- standard deviation of the anti-CCP units

was 80.61 +/- 55.5.2. Six of the 41 (14.6%) patients with osteoarthritis

studied had positive anti-CCP with a mean titer of 7.388. None of the

healthy controls exhibited positively for anti-CCP antibodies.

CONCLUSION: Anti-CCP antibodies may be found in patients with PsA and not in

our patients with only cutaneous psoriasis. These antibodies may also be

found in some patients with osteoarthritis and rarely in patients with UA;

such patients will be of interest to follow prospectively.

PMID: 17023808

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus & db=pubmed & cmd=R\

etrieve & dopt=abstractplus & list_uids=17023808

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