Electrolyte disturbances and abnormal urine analysis in children with dengue infection.

Serum electrolytes and urine analysis results were retrospectively reviewed in children with either dengue fever (DF) or dengue hemorrhagic fever (DHF). Children who had positive serology for dengue infection and serum electrolytes determined before starting intravenous fluid were included in the study. During the years 2004-2007, 73 DF patients, age 9.29 +/- 3.62 years, and 77 DHF patients, age 10.04 +/- 3.64 years were enrolled in the study. The patients were admitted to the hospital on average on days 4.12 +/- 1.1 and 4.25 +/- 1.4 of febrile illness for DF and DHF, respectively. The prevalence of hyponatremia in patients with DF was 61% and DHF was 72% (p = 0.149). The mean serum sodium levels in patients with DF and DHF were 133.5 +/- 3.52 and 133.5 +/- 3.20 mEq/l (p = 0.938), respectively. The prevalence of hyponatremia in patients with mild (grade I), moderate (grade II) and severe (grade III-IV) DHF were 70, 77, and 78% (p = 0.729), respectively, and the mean serum sodium levels were 134.1 +/- 3.05, 132.9 +/- 3.33, and 132.5 +/- 3.28 (p = 0.189), respectively. The prevalence of hypokalemia in patients with DF was 14% and 17% in patients with DHF (p = 0.588). A high urine specific gravity reflecting dehydration was found in 63% of patients with DF and 60% of patients with DHF (p = 0.77). The prevalences of hematuria in patients with DF and DHF were 18% and 27% (p = 0.182), respectively and proteinuria were 15% and 27% (p = 0.072), respectively. The prevalences of hematuria and proteinuria were not different among patients with mild, moderate and severe DHF. No patients had gross hematuria or developed acute renal failure requiring dialysis. Mild hyponatremia is a common electrolyte disturbance and renal involvement is mild in patients with DF and DHF.

Size and charge characteristics of the protein leak in dengue shock syndrome.

BACKGROUND: he mechanism underlying the transient vascular leak syndrome of dengue hemorrhagic fever (DHF) is unknown. We aimed to determine whether molecular size and charge selectivity, which help restrict plasma proteins within the intravascular space, are altered in patients with DHF and whether a disturbance of the anionic glycosaminoglycan (GAG) layer on the luminal endothelial surface contributes to disease pathogenesis. METHODS: We measured serial plasma levels and fractional clearances of proteins with different size and charge characteristics in 48 children with dengue shock syndrome (DSS) and urinary excretion profiles of heparan sulfate, chondroitin-4-sulfate, and chondroitin-6-sulfate in affected children and healthy control subjects. RESULTS: Compared with convalescent values, acute plasma concentrations of all proteins were reduced, with increased fractional clearances. Smaller proteins were more affected than larger molecules. Albumin, which is normally protected from leakage by its strong negative charge, demonstrated a clearance pattern similar to that of transferrin, a neutral molecule of similar size. Urinary heparan sulfate excretion was significantly increased in children with DSS. CONCLUSIONS: The endothelial size-dependent sieving mechanism for plasma proteins is at least partially retained, whereas selective restriction based on negative charge is impaired. The increased heparan sulfate excretion suggests a role for GAGs in the pathogenesis of the vascular leak.