Review 7 - hays

[ArchivalUser]

A 21-year-old man is evaluated in the emergency department for a 2-day history of anorexia, dyspnea, hemoptysis, and dark-colored urine. One month ago, he had a pulmonary infection. He has a history of chronic hepatitis C infection for which he has refused therapy. He takes no medications.
On physical examination, temperature is 37.4 °C (99.4 °F), pulse rate is 95/min, respiration rate is 25/min, and blood pressure is 168/98 mm Hg. The conjunctivae are pale. Bilateral inspiratory crackles are heard. A grade 2/6 systolic murmur is heard at the lower left sternal border. Abdominal and skin examinations are normal. There is bilateral 1+ lower-extremity edema.

Laboratory Studies
Hemoglobin 8.3 g/dL (83 g/L)
Leukocyte count 11,100/µL (11.1 × 109/L)
Platelet count 175,000/µL (175 × 109/L)
Blood urea nitrogen 73 mg/dL (26.1 mmol/L)
Creatinine 4.7 mg/dL (415.5 μmol/L)
Albumin 3.2 g/dL (32 g/L)
Serum complement (C3 and C4) Normal
Antinuclear antibodies Negative
Urinalysis 3+ blood; 2+ protein; 25-50 dysmorphic erythrocytes and 2 erythrocyte casts/hpf

Chest radiograph reveals bilateral fluffy infiltrates. A kidney biopsy is performed, and immunofluorescence microscopy shows necrotizing crescentic glomerulonephritis and a linear IgG staining pattern.

Which of the following is the most likely diagnosis?
a) Diffuse proliferative lupus nephritis
b) Goodpasture's syndrome
c) Cryoglobulinemia - Incorrect
d) Wegener's granulomatosis

[ArchivalUser]

Ans is B....both RS and Renal diseases due to Anti-GBM antibidies......

[ArchivalUser]

B,

[ArchivalUser]

D..on basis of one month ago he had pulmonary infection plus necrotic picture

[ArchivalUser]

Linear IgG staining pattern, answer is B. What is step1 question doing here?

[ArchivalUser]

Is not step 1 question is step 3

[ArchivalUser]

Thanks grigolia

[ArchivalUser]

@drstridor...

Wegeners also will have resp sysmptoms but the charectiristic feature is pauci-immune complex staining in immun microscopy.

[ArchivalUser]

Is MKSAP for step 1. Please let me know

[ArchivalUser]

it was just a quik review

Answer and Critique (Correct Answer = B)
Key Points

This patient has Goodpasture's syndrome. In this condition, circulating anti–glomerular basement membrane (GBM) antibodies cause rapidly progressive glomerulonephritis and may produce alveolar injury. Injury limited to the kidney is known as anti-GBM disease, whereas the combination of glomerulonephritis and alveolar hemorrhage is known as Goodpasture's syndrome. Some experts reserve the nomenclature Goodpasture's disease for the combination of glomerulonephritis, alveolar hemorrhage, and the presence of anti-GBM antibodies.

Anti-GBM disease and Goodpasture's syndrome are most often idiopathic but may follow pulmonary infections or injury, and systemic symptoms such as weight loss, fever, or arthralgia are either absent or not very prominent. The presence of systemic symptoms suggests the possibility of a complicating vasculitis, such as Wegener's granulomatosis, and ANCA testing would be indicated. Goodpasture's syndrome typically presents with dyspnea, cough, hemoptysis, and rapidly progressive glomerulonephritis characterized by proteinuria and gross hematuria. In affected patients, microscopic urinalysis reveals dysmorphic erythrocytes, leukocytes, and erythrocyte and granular casts. Additional findings may include the presence of pulmonary infiltrates on chest radiograph and iron deficiency anemia due to prolonged pulmonary bleeding. Renal biopsy and linear staining of anti-GBM antibodies on immunofluorescence microscopy confirm the diagnosis. Anti-GBM antibodies react with the α3 chain of type IV collagen in the GBM.

Diffuse proliferative lupus nephritis may present as a pulmonary-renal syndrome but is unlikely to develop in a man in the absence of other systemic manifestations of lupus, such as arthritis, skin rash, low complement levels, or positive antinuclear antibody titers. In addition, proliferative lupus nephritis is characterized by a “full-house” granular staining pattern (staining positive for IgG, IgA, IgM, C1q, C3, and C4) on immunofluorescence microscopy.

Cryoglobulinemia commonly occurs in patients with hepatitis C and may be associated with pulmonary hemorrhage and rapidly progressive glomerulonephritis. However, this condition is unlikely to be present in a patient with a normal C4 level. Patients with cryoglobulinemia also commonly develop palpable purpura, which reflects the underlying small-vessel vasculitis. Wegener's granulomatosis may be associated with pulmonary hemorrhage and normocomplementemic glomerulonephritis but typically is associated with more prominent systemic symptoms, such as fever and chills and weight loss. Up to 80% of patients with Wegener's granulomatosis also have upper airway symptoms, including sinusitis, nasal conditions, otitis, and hearing loss. Renal biopsy in Wegener's granulomatosis is characterized by pauci-immune complex staining on immunofluorescence microscopy.

Key Points
■Goodpasture's syndrome manifests as a normocomplementemic pulmonary-renal syndrome.
■Anti–glomerular basement membrane disease is characterized by linear staining of anti–glomerular basement membrane antibodies on immunofluorescence microscopy.