Pyuria in patients with Kawasaki disease

Area of Science:

• Pediatric Nephrology
• Rheumatology
• Infectious Diseases

Background:

• Kawasaki disease (KD) is an acute febrile vasculitis affecting children, potentially causing kidney injury.
• Pyuria, or white blood cells in urine, is a common finding in KD patients (30-80%).
• Sterile pyuria is more frequent in infants with KD and may correlate with severe inflammation and sub-clinical renal damage.

Purpose of the Study:

• To investigate the origins and implications of pyuria in Kawasaki disease.
• To differentiate between sterile pyuria and urinary tract infections (UTIs) in KD patients.
• To guide diagnostic workup for renal involvement in KD.

Main Methods:

• Analysis of urine cytology (mononuclear cells vs. neutrophils) in KD patients with pyuria.
• Review of clinical data to assess associations between pyuria type and disease severity.
• Evaluation of the incidence and characteristics of UTIs in KD patients.

Main Results:

• Sterile pyuria in KD is often associated with mononuclear cells and may stem from the urethra, kidneys, or bladder.
• Urinary tract infections (UTIs) can also cause pyuria in KD, with E. coli and K. oxytoca as common pathogens.
• Clinical presentation does not significantly differ between KD patients with or without UTIs.

Conclusions:

• Sterile pyuria in Kawasaki disease, particularly in infants, suggests potential renal involvement and warrants careful monitoring.
• KD patients with UTIs may have underlying urinary tract abnormalities, necessitating a comprehensive diagnostic workup.
• Recommended investigations for KD patients with UTIs include renal ultrasound, voiding cystourethrogram, and DMSA renal scan.