Transient depletion of innate immunity in varicella infections in otherwise healthy children.
OBJECTIVE
Varicella is a common childhood infection and has a number of complications in the unvaccinated population. Perforin, found in natural killer cells, is important for the killing of virally infected cells. For this reason, the aim of this study was to determine natural killer cell count and activity, perforin expression, and Fas and soluble Fas ligand (sFas-L) levels in immunocompetent children with varicella infection and define any possible relations between the levels and varicella complications.


METHODS
Forty children were analyzed at diagnosis and on the 15th day of varicella infection. There was a significant difference in hemoglobin levels and leukocyte and platelet counts between days 0 and 15.


RESULTS
Thirteen (32%) patients were found to be lymphopenic. Natural killer cell count and activity were significantly higher on day 15 when compared to values at diagnosis. The Fas-mediated apoptotic pathway was found to be active in acute varicella infection because Fas and sFas-L levels at diagnosis were higher than values on day 15.


CONCLUSIONS
These findings suggest that the Fas and Fas-L apoptotic pathway is active during the acute phase of the viral infection and that it becomes inactive by day 15, paralleling the hematologic recovery.
Nursat
N
Erdemli
Hacettepe University, Faculty of Medicine, Department of Pediatrics, Division of Pediatric Hematology, 06100 Sihhiye, Ankara,Turkey, Phone: +90 312 305 11 70 Fax: +90 312 311 23 98 E-mail: suleunal@hacettepe.edu.tr.
Şule
Ş
Ünal
Hamza
H
Okur
Gülten
G
Seçmeer
Ateş
A
Kara
Aytemiz
A
Gürgey