Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis by Mary A. Williamson Mt(ascp) Phd, L. Michael Snyder Md Read Free Book Online Page B

site/size of involved joints (score range 0–5)
   Serologic abnormality, based on serum levels of RF and anti–citrullinated protein antibody (score range 0–3)
   Elevated acute-phase response, based on CRP and ESR (score range 0–1)
   Symptom duration (< or ≥6 weeks; range 0–1)
   Who Should Be Suspected?
   Candidates are individuals presenting with fatigue, weakness, anorexia, and slowly progressive pain and swelling of the joints. Involvement of the small joints of the hands or feet should raise suspicion of RA. Early symptoms may also include fatigue, muscle pain, low-grade fever, weight loss, and numbness and tingling of the hands.
   Onset of RA most often occurs between the fourth and sixth decades of life but can also be seen in the pediatric population (juvenile rheumatoid arthritis) as well as the elderly. Women are three times more likely to develop RA than are men.
   Sixty to seventy percent of RA patients of European ancestry carry the HLA-DR4 gene compared to 30% in the general population, indicating a genetic predisposition.
   Laboratory Findings
    There is no pathognomonic test for RA. Tests for diseases that can mimic RA (hemochromatosis, SLE, systemic sclerosis, sarcoidosis) may be indicated.
   RF is positive in approximately 80% of patients within one year of presentation, but in only 30% at the onset of arthritis. In the absence of RF (15–20% of cases), the disease is called seronegative RA.
   Anti–citrullinated protein antibody, tested as anti-CCP or anti–mutated citrullinated vimentin, is more specific for RA than RF. Anti-CCP antibodies are found in 60–70% of RA cases and have approximately 95% specificity.
   ANA test is positive in 25–50% of patients.
   Synovial fluid analysis reveals an inflammatory pattern with increased WBC counts (2,000–50,000/μL in affected joints), with a predominance of neutrophils. Total hemolytic complement, C3, and C4 are markedly reduced.
   ESR and CRP are elevated.
Suggested Reading
Aletaha D, Neogi T, Silman AJ, et al. 2010 rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum. 2010;62(9):2569–2581.
SJÖGREN SYNDROME
   Definition
   Sjögren syndrome (SjS) is an inflammatory, autoimmune disease in which the exocrine glands, mainly the salivary and lacrimal glands, are attacked and destroyed by the immune cells.
   The syndrome is divided into primary SjS (not associated with other diseases), or secondary SjS, which is associated with other autoimmune rheumatic conditions, principally rheumatoid arthritis (most common) or SLE. In both primary and secondary SjS, decreased exocrine gland function leads to the “sicca complex,” characterized by dry mouth (xerostomia) and dry eyes (keratoconjunctivitis sicca).
   The American-European Consensus Group criteria for classification of SjS were developed in 2002. In 2012, new criteria were proposed by the American College of Rheumatology and the Sjögren’s International Collaborative Clinical Alliance. Using the later criteria, classification of SjS, which applies to individuals with signs/symptoms that may be suggestive of SjS, will be met in the presence of at least two of the following three objective features:
   Positive serum anti-SSA/Ro and/or anti-SSB/La or positive rheumatoid factor and ANA titer ≥1:320
   Labial salivary gland biopsy exhibiting focal lymphocytic sialadenitis with a focus score ≥1 focus/4 mm 2
   Keratoconjunctivitis sicca with ocular staining score ≥3 (assuming that the individual is not currently using daily eye drops for glaucoma and has not had corneal surgery or cosmetic eyelid surgery in the last 5 years)
   Who Should Be Suspected?
   SjS patients typically present with complaints of ocular symptoms, such as persistent dry eyes for more than 3 months and oral symptoms of dryness (e.g., the