Immunopathology — MCQs

A 32-year-old Black woman with no occupational exposures presents with progressive dyspnea, fatigue, and bilateral ankle swelling. She also reports erythema nodosum on her shins. A chest radiograph shows bilateral hilar enlargement and diffuse interstitial infiltrates. Bronchoscopic biopsy is performed. The biopsy shows discrete, well-formed granulomas without central necrosis, surrounded by a rim of lymphocytes, with occasional Schaumann bodies and asteroid inclusions within giant cells. No organisms are identified on special stains. Which of the following best describes the predominant immunological mechanism driving this morphological pattern?

A 45-year-old woman presents with fatigue and jaundice. Serology is positive for anti-smooth muscle antibodies and elevated IgG. A liver biopsy is performed and shows a dense lymphoplasmacytic infiltrate expanding the portal tracts with interface hepatitis (piecemeal necrosis), plasma cell rosettes, and scattered acidophil bodies within the lobule. The lobular architecture is preserved. Which of the following findings, if present on the same biopsy, would most strongly support progression to an irreversible stage of this disease process?

A 34-year-old woman presents with painless cervical lymphadenopathy, night sweats, and a 6 kg weight loss over 3 months. Excisional lymph node biopsy is performed. The photomicrograph demonstrates effacement of nodal architecture by a mixed inflammatory infiltrate of lymphocytes, plasma cells, eosinophils, and neutrophils. Scattered large binucleated cells with prominent eosinophilic 'owl-eye' nucleoli are identified; these cells are CD15+, CD30+, CD20−, and CD45−. A second population of mononuclear variants with similar nuclear features is also present. Which of the following most accurately characterizes the large binucleated cells in this biopsy?

A 40-year-old woman with myasthenia gravis on pyridostigmine develops worsening weakness, diplopia, and dysphagia. She recently had URI and received azithromycin. Exam shows bilateral ptosis, ophthalmoplegia, and proximal muscle weakness with preserved reflexes. Her acetylcholinesterase inhibitor dose was increased 3 days ago. Edrophonium test shows no improvement. ABG shows hypercapnia. Evaluate the synthesis of clinical findings and determine the life-threatening complication requiring immediate intervention.

A 32-year-old pregnant woman at 20 weeks gestation with known anti-Rh(D) antibodies from previous pregnancy presents for routine prenatal care. Her current fetus is Rh(D)-positive by cell-free DNA testing. Middle cerebral artery Doppler shows increased peak systolic velocity. Fetal ultrasound reveals polyhydramnios and ascites. Amniocentesis shows elevated bilirubin. Synthesize the pathophysiology and evaluate the therapeutic intervention that addresses the underlying immune mechanism.