A physician is reviewing the charts of four newly admitted patients with complex multisystem presentations. Match each patient's clinical scenario with the most appropriate targeted laboratory investigation to establish the underlying diagnosis.
- A 45-year-old individual presents with recent onset of hemoptysis, rapidly progressive acute kidney injury, and ulceration of the nasal septum.Measurement of antineutrophil cytoplasmic antibodies (ANCA)
- A 55-year-old patient with chronic, untreated Hepatitis C infection develops palpable purpura on the lower extremities, severe joint pain, and an acute decline in renal function.Evaluation for serum cryoglobulins
- A 25-year-old individual with a history of three consecutive first-trimester miscarriages presents with an unprovoked deep vein thrombosis and a paradoxically prolonged activated partial thromboplastin time (aPTT).Antiphospholipid antibody panel
- A 60-year-old patient reports severe, unrelenting lower back pain and is found to have a normocytic anemia, hypercalcemia, and an elevated serum creatinine.Serum protein electrophoresis and free light chain assay
Answer
The patient with hemoptysis and nasal ulcers requires ANCA testing. The Hepatitis C patient with purpura requires serum cryoglobulin testing. The patient with recurrent miscarriages and DVT requires an antiphospholipid antibody panel. The older patient with back pain, anemia, and hypercalcemia requires serum protein electrophoresis and free light chain testing.
Each patient presentation is a classic description of a multisystem disease requiring specific initial laboratory testing. Granulomatosis with polyangiitis requires ANCA. Mixed cryoglobulinemia secondary to Hepatitis C requires cryoglobulin testing. Antiphospholipid syndrome necessitates a specific antibody panel. Multiple myeloma requires SPEP and free light chains.
Step-by-Step Solution
Key Concept
Targeted laboratory testing must be guided by pattern recognition of classic multisystem clinical syndromes.