<prompt> A 17-year-old woman is brought to the physician by her parents because she has been acting strangely for a couple of days. Over the past 3 months, she has experienced malaise, joint pain, weight loss, and sporadic fever. The patient appears agitated, with a temperature of 38degC 101degF. Other physical findings include malar rash, erythematous-pink plaques with telangiectatic vessels, oral ulcers, and nonblanching purpuric papules on her legs. Laboratory studies show elevated levels of BUN and creatinine. The anti-double-stranded DNA antibody test is positive. Biopsy of sun-damaged lesional skin would most likely show which of the following histopathologic findings in this patient?Acanthosis, parakeratosis, and neutrophils within the stratum corneumEarly dermal-epidermal separation mediated by eosinophilsGranular distribution of immune complexes in the basement membrane zoneLinear IgA deposits within dermal papillae  <response>: The patient exhibits signs and symptoms of systemic lupus erythematosus SLE, a disorder characterized by a variety of autoantibodies and other immune abnormalities indicating B-cell hyperactivity. Epidermal cellular damage initiated by light or other exogenous agents causes the release of a large number of antigens, some of which may return to the skin in the form of immune complexes. Immune complexes are also formed in the skin by a reaction of local DNA with antibody that may also be deposited beneath the epidermal basement membrane zone. The other choices are not features of SLE.Diagnosis: Systemic lupus erythematosus 