Rheumatoid arthritis is diagnosed through clinical, laboratory, and radiological features and are summarized through different protocols.
Diagnosis
American College of Rheumatology (ACR)-Criteria-1987
According to the American College of Rheumatology (ACR), Criteria-1987 diagnosis for RA required is 4 out of 7 below mentioned criteria should be there for more than 6 weeks at least
- Early morning Stiffness lasting for an hour
- Arthritis of three or four joints
- Small joints of the hand and foot should be involved
- Arthritis should be symmetrical
- Rheumatoid nodules should be better
- Positive RF test to be present
- Radiologically articular surface erosion and periarticular osteopenia should be there
The problem of this criteria is not intended to diagnose routine cases but used for research work
ACR/EULAR (European League against rheumatism) criteria
A score of >6/10 is needed to classify the patient as having definite RA
A. Joint Involvement
| 1 Large joint | 0 |
| 2-10 Large joints | 1 |
| 1-3 Small joints (with or without large joints) | 2 |
| 4-10 Small joints (with or without large joints) | 3 |
| > 10 joints (at least 1 small joint) | 5 |
B. Serology (at least 1 test needed for classification)
| Negative RF and negative ACPA (anticitrullinated protein antibodies) | 0 |
| Low positive RF and low positive ACPA | 2 |
| High positive RF and high positive ACPA | 3 |
C. Acute phase reactants (at least 1 test needed for classification)
| Normal CRP and normal ESR | 0 |
| Abnormal CRP and abnormal ESR | 1 |
D. Duration of symptoms
| < 6 weeks | 0 |
| >_ 6 weeks | 1 |
Investigations for RA
A. Laboratory test
- Complete automated blood counts
- Liver function test
- Renal Function test
- Urine analysis
- Viral markers
Hypochromic Normochromic Anemia is frequently associated
B. Acute phase reactants
- ESR and CRP are raised
C. Special test
Rheumatoid factor test:
It is a sensitive quantitative test but positive in 60-70% of patients
RA factor is an antibody that binds to Fc portion of IgG
Negative RA factor does not rule out RA, seronegative RA (Arthritis may be RA factor negative)
During 1st year of onset of the disease arthritis may be RA factor negative but later 70 % converts to positive
False-positive is seen in
- Other Rheumatoid disease
- Chronic infections
- Sjogren’s syndrome
10% healthy population have positive RA factor, So this test is not very specific
Anti cyclic citrullinated peptides (Anti-CCP)
Anti-CCP is present in 70-80% of all RA patients, but rarely positive in non-RA patients
Specificity=95%
False-positive is seen in active tuberculosis
Anti-CCP can be positive in the early stage of RA or even before the onset of the disease
In early cases of RA, clinical symptoms are sometimes mild and non-specific and the patient may not fulfill even definite ACR criteria
In early RA, the presence of anti-CCP with or without positive RA factor may be associated with a more erosive disease that is aggressive in nature.
Anti-Nuclear Antibodies(ANA)
30-40 % of RA patients may have ANAs positive
Synovial Fluid Analysis
It helps to exclude other forms of arthritis as gouty infection
WBC Count: 5000-50,000/mm3
Rarely WBC exceeds 1,00,000/mm3 (Pseudoseptic)
MRI
MRI wrist may show tendinopathy; the earliest sign of RA
USG
Synovial thickening
Treatment Options
- Conventional Therapy
- Non-steroidal anti-inflammatory drugs
- Disease-modifying anti-rheumatoid drugs
- Corticosteroids
- Biologicals
Corticosteroids are given in early RA and in a rheumatoid flare-up
Can be given to women, who develop RA in early pregnancy but again for a short duration
Extraarticular RA: Steroid + DMARDS
DMARDs should be started as early as possible to minimize joint damage
CBC, LFT, and RFT should be done prior onset of DMARDs
DMARDs usually take 3-6 months to act once started
History of pregnancy in young patients must be taken
Common Drugs:
A. Methotrexate (MTX)
The gold standard for mild and moderate cases
Inhibits dihydrofolate reductase (enzymes involved in DNA synthesis)
Both anti-inflammatory + Cytostatic effects
Low doses in RA, MTX from 7.5 mg/week to 25 mg/week slowly
The parental route is preferred due to better bioavailability and tolerability
Antiinflammatory effects of drugs usually appear after a minimum of 4-6 weeks
ADR: Bone marrow suppression, Liver toxicity,
The safety profile is increased by adding 1mg/day of folic acid
B. Sulfasalazine
Used alone in the mild form of RA or in contraindication to MTX
Effects come after 3-6 months of initial therapy
This molecule is linked to antibiotics known as sulfapyridine and with an antiinflammatory agent called 5-aminosalicylic acid
No teratogenic so safe in pregnancy
Doses: 1-2 gram/day
ADR: Dyspepsia, rashes, bone marrow suppression, and oligospermia
C. Hydroxychloroquine
In the mild form of RA
200-400 mg /day
The safe drug requires no monitoring
ADR: Headache, dyspepsia, and long-term usage leads to retinal changes
So, regular retinal checks should be done
D. Leflunomide
Very toxic but potent drug to treat RA
(Should not be used in young females)
Doses of LEF: 10-20 mg/day
Inhibits the enzyme involved in pyrimidine synthesis
Elimination can be increased by cholestyramine
ADR: diarrhea, hypertension, skin rashes. alopecia, liver toxicity
Combination therapy is used if results are not satisfactory with DMARDs
Biological
TNF Inhibitors
- Infliximab
- Adalimumab
- Etanercept
- Certolizumab
- Golimumab
T-cell inhibitors
- Abatacept
IL-6 inhibitors
- Tocilizumab
B-cell depleting therapy
- Rituximab
Cytotoxic therapies
- Azathioprine
- Cyclosporine
Physiotherapy and occupational therapy
Poor Prognostic factors in RA
- Early erosive disease
- Extraarticular involvement
- Positive RF
- Positive anti-CCP
- HLA-DR4
- Family history of RA
- Persistent synovitis despite treatment
- Persistently elevated ESR level / CRP level
- Older age of onset of disease
- Low socio-economic education level
EULAR recommendation for management of rheumatoid arthritis with synthesis and biological disease-modifying antirheumatic drugs -2019 update
See also: Rheumatoid arthritis(RA) of the cervical spine
See also: Rheumatoid Hand
See also: Rheumatoid Foot and Ankle deformities
