A 16-year-old male goes to his physician for an annual checkup.A routine urinalysis indicates the presence of blood,an increase in protein,and an increase in urea.The young man reports that he has been feeling tired and has a persistent cough.The doctor orders additional laboratory testing,including a serum test for rheumatoid factor,antinuclear antibody testing,anti-streptolysin O testing,and testing for the presence of anti-basement membrane antibodies.Only the latter test was positive.What disease is the most likely cause of the symptoms?

Question

Quizplus · Accepted Answer

The presence of blood and protein in the urine, along with an increase in urea, suggest renal involvement. The positive test for anti-basement membrane antibodies indicates Goodpasture's syndrome, an autoimmune disorder that can cause lung and kidney damage. The patient's tiredness and persistent cough also fit with the diagnosis. Systemic lupus erythematosus can cause similar symptoms, but the additional laboratory tests were negative for markers of that disease. Multiple sclerosis and rheumatoid arthritis would not be expected to cause the urinary and respiratory symptoms seen in this case.

A 16-Year-Old Male Goes to His Physician for an Annual