Anti-cyclic citrullinated peptide antibody＝ACPA
The most important item in diagnosing and treating rheumatism is the blood test item called anti-CCP antibody.
First, the normal value (unit) is less than 4.5 (U / mL).
This is a number that is common to most laboratories in Japan.
(Reference values may differ when surveyed overseas)
Anti-CCP antibody positive rate of healthy Japanese is 1.5-2%.
(Estimated from data from clinical surveys, based on surveys at SEIROKA International Hospital)
Patients who later developed rheumatoid arthritis have been found to be positive long before the onset.
It has been found that if anti-CCP antibodies happen to be positive in a medical checkup, rheumatoid arthritis develops within a few years (several months to 5 years) with a probability of 80% or more.
Since it becomes positive from almost no symptoms, it can be used to predict the onset of rheumatoid arthritis.
For example, if you are worried about heredity, such as when your mother or brother has multiple patients with rheumatoid arthritis, you may want to check it once.
Values of anti-CCP antibodies and rheumatic severity
The number of anti-CCP antibodies itself is not clearly proportional to the severity of rheumatism.
However, roughly speaking, if you compare the positive number below 20 and the positive number of the anti-CCP antibody above that, there is no doubt that the higher group has a stronger momentum of rheumatism.
In addition, those with high numbers tend to have long-term treatment (5 to 10 years or more). Evidence literature # 1 # 2
It is also known that anti-CCP antibody positive people who develop rheumatoid arthritis develop joint joints severely within 1 to 3 years without sufficient early treatment.
Therefore, it is important to treat patients with high anti-CCP antibodies by aggressively taking the lead.
Will the number of anti-CCP antibodies go down?
It seems that the number of anti-CCP antibodies often decreases as the drug works and rheumatism improves.
However, the anti-CCP antibody expresses the part that is very close to the onset of rheumatism, so it is not necessarily proportional to the symptoms that appear on the actual surface, and the numbers continue to rise even if it gets better You can also see the case.
Therefore, it is not always useful in determining the therapeutic effect of rheumatism.
In the medical treatment after rheumatism diagnosis, only the measurement for the purpose of judging the biological product change is allowed.
If anti-CCP antibody is positive,When should I start treatment?
We do not give pharmacological treatment to patients who are positive for anti-CCP antibodies but who are completely asymptomatic.
There is a classification standard (ACR / EULAR2010 standard) for rheumatism used worldwide.
Most specialists seem to start treatment based on this.
It’s a very well-thought-out criterion, so it ’s not too late to start treatment immediately after meeting this criterion.
However, even if CRP is normal, cervical vertebral synovitis lesions and early inflammatory findings that can only be found by ultrasound or MRI are often found.
Thorough examination and evaluation of whether or not rheumatism has really begun is important in order to not miss the timing of appropriate treatment initiation.
In addition, even if treatment is started, there are many cases where joint destruction progresses if inflammation continues with drugs that are ineffective.
Is remission possible for rheumatoid arthritis possible―Fredinand C.Breedveld APLAR 2010
Undiagnosed arthritis (UA) is a disease state in which symptoms of arthritis are observed but RA (rheumatism) diagnostic criteria are not satisfied and other arthritis is not diagnosed, about 30% of patients are confirmed as RA with one year later It is known that natural remission occurs in some patients. In the PROMPT study ( van Dongen H et al. Arthritis Rheum 2007; 56 (5): 1424-1432 ) which examined the effectiveness of MTX on UA, RA onset was significantly suppressed in anti-CCP antibody positive UA patients (p = 0.0002), the progression of X-ray findings was also significantly suppressed (p = 0.03), but no effect was observed in anti-CCP negative cases, indicating that the effect of early MTX administration varies depending on the presence or absence of anti-CCP antibody . For that reason, Professor Breedveld pointed out, "For patients with UC who are positive for anti-CCP, it is important to start treatment immediately instead of follow-up and to suppress progression to RA."
#1 Berglin E,Johansson T,Sundin U,et al:Radiological outcome in rheumatoid arthritis is predicted by presence of antibodiesagainst cyclic citrullinated peptide before and at disease onset,and by IgA-RF at disease onset.―
#2 Syverrsen SW,Gaarder PI,Gokk GL,et al:High anti-CCP levels and an algorithm of four variables predict radiographic progression in patients with rheumatoid arthritis: results from a 10-year longitudinal study―
Alessandri C,Bombardieri M,Papa N,et al:Decrease of anti-cyclic citrullinated peptide antibodies and rheumatoid factor following anti-TNFα therapy (infliximab) in rheumatoid arthritis is associated with clinical improvement―
Caramaschi P,Biasi D,Tonolli E,et al:Antibodies against cyclic citrullinated peptides in patients affected by rheumatoid arthritis before and after infliximab treatment―
De Rycke L,Verthlst X,Kruithof E,et al:Rheumatoid factor, but not anti-cyclic citrullinated peptide antibodies, is modulated by infliximab treatment in rheumatoid arthritis―
van Dongen H et aｌ.Arthritis Rheum 2007;56(5): 1424-1432 Efficacy of Methotrexate Treatment in Patients With ProbableRheumatoid Arthritis