Case Studies
A 7-year-old boy was brought to his pediatrician because he had developed hematuria, which required
hospitalization. Approximately 6 weeks before his admission, he had a severe sore throat but received no
treatment for it. Subsequently, he did well except for complaints of mild lethargy and decreased appetite.
Approximately 3 weeks before admission, he had a temperature of 101° F daily for 7 days. He complained
of minimal bilateral back pain. Physical examination revealed a well-developed young boy with moderate
bilateral costovertebral angle (CVA) tenderness. The remainder of the physical examination results were
negative. His blood pressure was 140/100 mm Hg in both arms and legs.
Studies Results
Urinalysis,
Blood +4 (normal: negative)
Protein +1 (normal: negative)
Red blood cell casts Positive (normal: negative)
Specific gravity 1.025 (normal: 1.010-1.025)
Color Red-tinged (normal: amber-yellow)
Urine culture and sensitivity (C&S), No growth after 48 hours
Blood urea nitrogen (BUN), 42 mg/dL (normal: 7-20 mg/dL)
Creatinine, 1.8 mg/dL (normal: 0.7-1.5 mg/dL)
Creatinine clearance test, 64 mL/min (normak approximately 120 mL/min)
Renal ultrasound, No tumor; kidneys diffusely enlarged and edematous
Intravenous pyelogram (IVP), Delayed visualization bilaterally; enlarged
kidneys, no tumor; no obstruction seen
Renal biopsy, Swelling of glomerular tuft, along with polymorphonuclear leukocyte infiltrates in Bowman’s
capsule (findings compatible with glomerulonephritis):
immunofluorescent staining, positive for IgG
Anti-DNase-B (ADB) titer, 200units (normal: $170 units)
Total complement assay, 33 units/mL (normal: 75-160 units/mL)
Diagnostic Analysis tT
The blood, protein, and RBC casts in the boy’s urine indicated a primary renal disorder. The elevated ‘
creatinine and BUN levels indicated that the problem was severe and markedly affecting his renal function.
Both kidneys were probably equally impaired. intravenous pyelogram (IVP) was helpful only in ruling out
Wilms tumor or congenital abnormality.
Normally an IVP would not be performed in light of this patient’s impaired renal function. It
is presented here for demonstration of the information it can provide. Renal ultrasound is a
much safer test to visualize the kidney to exclude neoplasm. The ultrasound findings were
compatible with an inflammatory process involving both kidneys. Renal biopsy was most
helpful in suggesting glomerulonephritis. The history of recent pharyngitis, fever, the
positive ASO titer, the positive ADB titer, and the finding of immunoglobulin IgG antibodies
on the immunofluorescent stain ail suggested poststreptococcal glomerulonephritis.
The patient was placed on a 10-day course of penicillin. He was given antihypertensive
medication, and his fluid and electrolyte balance was closely monitored. At no time did his
creatinine or BUN level rise to a point requiring dialysis. After 6 weeks, his renal function
returned to normal (creatinine, 0.7 mg/dL; BUN, 7 mg/dL). His antihypertensive medications were
discontinued, and he remained normotensive and returned to normal activity.
Critical Thinking Questions
- At what point would the BUN and creatinine have signified the need for dialysis? °
- What was the cause of the patient’s hypertension?
- What would you do if this patient had developed a swollen mouth and neck after the
IVP?
Sample Solution
