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 A

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   Possibly other organisms (e.g., HIV, Escherichia coli , Mycoplasma genitalium ).
   HLA-B27 is positive in approximately half of the patients and seems to be associated with a more sudden and severe onset of symptoms as well as increased likelihood to have chronic (long-lasting) disease.
   Elevated ESR and CRP during the acute phase of disease.
   RF is negative.
   Synovial fluid analysis shows elevated WBC count, predominantly neutrophils, and may help distinguish reactive arthritis from other forms of arthritis.
RETROPERITONEAL FIBROSIS
   Definition
   A rare disease characterized by the presence of fibrosclerotic tissue in the retroperitoneum, often leading to encasement of the ureters and, less frequently, blood and lymphatic vessels.
   About two thirds of the cases are idiopathic, while the remaining cases are secondary to a variety of causes, including drugs (e.g., beta-blockers, methyldopa, hydralazine, analgesics), tumors (e.g., Hodgkin disease and non-Hodgkin lymphoma, sarcomas, carcinomas), infections (e.g., TB, histoplasmosis, actinomycosis), radiation, or surgery.
   Idiopathic retroperitoneal fibrosis is part of the disease spectrum of chronic periaortitis, which is characterized by inflammation and fibrosis surrounding the aorta and iliac arteries. It has also been suggested that idiopathic retroperitoneal fibrosis is a manifestation of either a systemic autoimmune disorder or IgG4-related disease.
   Who Should Be Suspected?
   Most patients present with abdominal, lower back, or flank pain. In addition, up to one half of patients complain of constitutional manifestations such as fever, weight loss, fatigue, and night sweats. Renal failure due to obstruction of the ureters develops in more than 40% of patients, and newonset hypertension has been reported in approximately one third of patients.
   The idiopathic disease most commonly occurs in individuals 40–60 years of age. Men are affected two to three times more than women.
   Laboratory Findings
    Diagnosis is established by imaging studies.
   ESR and CRP are elevated in approximately one half to two thirds of patients.
   Anemia of chronic inflammation (normochromic, normocytic) is a frequent finding and can also be related to renal dysfunction.
   Leukocytosis, eosinophilia, hyperferritinemia, or hypergammaglobulinemia may be present in some patients.
   ANA test is positive in up to 60% of cases.
   Serum IgG4 levels are frequently elevated in patients with IgG4-related disease.
   Blood urea nitrogen (BUN) and creatinine can be elevated; levels are variable depending on the presence and size of urinary obstruction. Urine sediment is often normal.
Suggested Reading
Pipitone N, Vaglio A, Salvarani C. Retroperitoneal fibrosis. Best Pract Res Clin Rheumatol. 2012;26(4):439–448.
Retroperitoneal Fibrosis
   Definition
   Rheumatoid arthritis (RA) is a chronic inflammatory arthritis characterized by progressive, symmetric joint swelling, tenderness, and destruction, leading in some cases to severe disability and premature mortality. The potential of synovitis to cause cartilage damage and bone erosion is characteristic for the disease. In addition to joints, RA may affect many other tissues and organs (e.g., lungs, pleura, pericardium, sclera), but the joints are usually most severely affected.
   Given the presence of autoantibodies, RA is considered an autoimmune disease, and it is the most common type of autoimmune arthritis. Autoimmunity and the overall systemic and articular inflammatory load drive the destructive progression of the disease.
   According to the 2010 ACR/EULAR criteria, classification of RA is based on the confirmed presence of synovitis in at least one joint, absence of an alternative diagnosis that better explains the synovitis, and achievement of a total score of 6 or greater (of a possible 10) from the individual scores in four domains:
   Number and