Explanation: 👍🏻The correct answer is B. Anti-IgG autoantibodies, also known as rheumatoid factor; are present in 80% of patients with rheumatoid arthritis (RA). RA is an autoimmune disease leading to inflammation and degeneration of joint spaces. This patient has a classic presentation of RA, with complaints of morning stiffness, bilateral joint pain, and improvement with use. Many patients also have a family history of RA.
👎🏻A is not correct. Anti-double stranded DNA (dsDNA), along with anti-Smith antibodies, are specific for systemic lupus erythematosus. In this autoimmune disorder; patients often develop malar or discoid rashes, photosensitivity, and renal dysfunction. They can also develop arthritis.
👎🏻C is not correct. In patients with rheumatoid arthritis, rheumatoid factor is an IgM against the Fc portion of IgG.
👎🏻D is not correct. Antineutrophil antibodies are implicated in vasculitides such as microscopic polyangiitis and granulomatosis with polyangiitis (formerly called Wegener).
👎🏻E is not correct. Antinuclear antibodies (ANAs) are implicated in a number of autoimmune disorders and are most strongly associated with systemic lupus erythematosus. About 41% of patients with rheumatoid arthritis (RA) are ANA positive. However, the presence of these antibodies does not confirm the diagnosis of RA. Both of these present with renal pathology (hematuria, proteinuria, rapidly progressive glomerulonephritis, renal failure). Granulomatosis with polyangiitis also has respiratory pathology (hemoptysis, perforation of nasal septum, chronic sinusitis, cough, dyspnea).
👎🏻A is not correct. Anti-double stranded DNA (dsDNA), along with anti-Smith antibodies, are specific for systemic lupus erythematosus. In this autoimmune disorder; patients often develop malar or discoid rashes, photosensitivity, and renal dysfunction. They can also develop arthritis.
👎🏻C is not correct. In patients with rheumatoid arthritis, rheumatoid factor is an IgM against the Fc portion of IgG.
👎🏻D is not correct. Antineutrophil antibodies are implicated in vasculitides such as microscopic polyangiitis and granulomatosis with polyangiitis (formerly called Wegener).
👎🏻E is not correct. Antinuclear antibodies (ANAs) are implicated in a number of autoimmune disorders and are most strongly associated with systemic lupus erythematosus. About 41% of patients with rheumatoid arthritis (RA) are ANA positive. However, the presence of these antibodies does not confirm the diagnosis of RA. Both of these present with renal pathology (hematuria, proteinuria, rapidly progressive glomerulonephritis, renal failure). Granulomatosis with polyangiitis also has respiratory pathology (hemoptysis, perforation of nasal septum, chronic sinusitis, cough, dyspnea).