USMLE Forum Archives - USMLE Step 3 - Wats the causative agent?
Wats the causative agent?
meduploader - 05-05-09 15:28
A 41-year-old woman is evaluated because of fever, a nonproductive cough, dyspnea, and diarrhea. The patient underwent cadaveric renal transplantation for diabetic nephropathy 5 weeks ago. Her immunosuppressive therapy includes cyclosporine and prednisone plus one course each of muromonab CD3 (OKT3) and monoclonal antibody for rejection at 1 and 3 weeks post-transplant. Pre-transplant cytomegalovirus antibody titer was positive. Since transplantation, she has received prophylactic acyclovir, 200 mg orally four times daily.
On physical examination, temperature is 38.8 °C (101.8 °F), pulse rate is 110/min, respiration rate is 18/min, and blood pressure is 140/85 mm Hg. She is alert and oriented but is moderately dyspneic. There is no evidence of rash. Funduscopic examination is normal. Faint crackles are heard at both lung bases. Cardiac and abdominal examinations are normal. The surgical scar is well healed. A stool specimen is liquid and is positive for occult blood. Neurologic examination is normal.
Laboratory Studies
Hemoglobin
10.5 g/dL
Leukocyte count
5000/μL (50% polymorphonuclear neutrophils, 21% monocytes, 25% lymphocytes, occasional atypical lymphocytes)
Serum creatinine
1.5 mg/dL
Serum aspartate aminotransferase
78 U/L
Serum alanine aminotransferase
80 U/L
Arterial blood PO2 (patient breathing room air)
75 mm Hg
A chest radiograph shows bilateral interstitial pneumonitis.
Which of the following pathogens is most likely causing this patient’s current findings?
meduploader - 05-05-09 15:28
A 41-year-old woman is evaluated because of fever, a nonproductive cough, dyspnea, and diarrhea. The patient underwent cadaveric renal transplantation for diabetic nephropathy 5 weeks ago. Her immunosuppressive therapy includes cyclosporine and prednisone plus one course each of muromonab CD3 (OKT3) and monoclonal antibody for rejection at 1 and 3 weeks post-transplant. Pre-transplant cytomegalovirus antibody titer was positive. Since transplantation, she has received prophylactic acyclovir, 200 mg orally four times daily.
On physical examination, temperature is 38.8 °C (101.8 °F), pulse rate is 110/min, respiration rate is 18/min, and blood pressure is 140/85 mm Hg. She is alert and oriented but is moderately dyspneic. There is no evidence of rash. Funduscopic examination is normal. Faint crackles are heard at both lung bases. Cardiac and abdominal examinations are normal. The surgical scar is well healed. A stool specimen is liquid and is positive for occult blood. Neurologic examination is normal.
Laboratory Studies
Hemoglobin
10.5 g/dL
Leukocyte count
5000/μL (50% polymorphonuclear neutrophils, 21% monocytes, 25% lymphocytes, occasional atypical lymphocytes)
Serum creatinine
1.5 mg/dL
Serum aspartate aminotransferase
78 U/L
Serum alanine aminotransferase
80 U/L
Arterial blood PO2 (patient breathing room air)
75 mm Hg
A chest radiograph shows bilateral interstitial pneumonitis.
Which of the following pathogens is most likely causing this patient’s current findings?
The correct answer and explanation will be available after you answer.
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#4
Re: Wats the causative agent? bingousmle - 05-06-09 00:01 My answer is: d.
CMV pneumonitis is often a late complication of transplant procedures..
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