Glomerulonephritis

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, p. 956

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), p. 973 No growth after 48 hours

Blood urea nitrogen (BUN), p. 511 42 mg/dL (normal: 7-20 mg/dL)

Creatinine, p. 190 1.8 mg/dL (normal: 0.7-1.5 mg/dL)

Creatinine clearance test, p. 193 64 mL/min (normal: approximately 120

mL/min)

Renal ultrasound, p. 866 No tumor; kidneys diffusely enlarged and

edematous

Intravenous pyelogram (IVP), p. 1057 Delayed visualization bilaterally; enlarged

kidneys, no tumor; no obstruction seen

Renal biopsy, p. 751 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, p. 79 200 units (normal: ≤170 units)

Total complement assay, p. 172 33 units/mL (normal: 75-160 units/mL)

Case Studies 2

Diagnostic Analysis

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 all 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

1. At what point would the BUN and creatinine have signified the need for dialysis? 2. What was the cause of the patient’s hypertension? 3. What would you do if this patient had developed a swollen mouth and neck after the

IVP?