Egypt J Pediatr Allergy Immunol, (October 2003), Volume No. 1, Issue 02  
Egypt J Pediatr Allergy Immunol 2003 ; 1 ( 02 ) : 110-117 -
, ESP - 94  
T cell activation markers “CD45RO and CD45RA”; neutrophil CD11b expression and soluble tumor necrosis factor receptor (p55) in early diagnosis of neonatal sepsis.
Magda A. Khazbak   Safaa S. Imam   Hala Abd El-Khalik   Maha H. Mohamed      
Background: Neonatal sepsis is a common and life threatening disorder whose outcome and prognosis depend on early and efficient therapy. A sensitive and specific indicator at an early stage of the disease would certainly aid the early diagnosis of neonatal sepsis. Objective: We sought to investigate the diagnostic value of measuring the up-regulation of T-lymphocyte activation markers CD45RA/CD45RO, CD45RO, neutrophil CD11b expression, and soluble tumor necrosis factor receptor (P55) as tests for early detection of neonatal sepsis; as well as comparing them with the conventional methods of diagnosis. Methods: The subjects of this study comprised 39 neonates: 25 males (64%) and 14 females (36%). In addition to the clinical assessment, different laboratory investigations for the diagnosis of sepsis were done. These included a complete blood picture, quantitative measurement of C-reactive protein and blood and or CSF culture and sensitivity. Assays for T cell activation markers CD45RA/CD45RO and neutrophil CD11b by flow cytometry and soluble tumor necrosis factor receptor sTNFR1 by ELISA were carried out as well as chest plain x-raying. Results: The up-regulation of CD45RA/ CD45RO dual expression and CD45RO expression on T-lymphocytes was observed in the septic group. The percent expression of CD45RA/CD45RO and CD45RO was significantly elevated in the high-risk group when compared to the control group. However, CD45RA/CD45RO and CD45RO showed no significant difference in percent expression between the septic group and the high-risk group. CD11b expression was also significantly higher in the septic (72.8± 17.8) than the control group (17.2 ±9.9%, p<0.05) and also in the high- risk group (42.2 ± 25.9%, p<0.05) as compared to the control group. sTNFR55 was significantly high in septic group (18.14 ± 9.38 ng/ml) as well as in the high risk group (26.90 ± 16.89 ng/ml) when compared to the control group (6.44 ± 1.49 ng/ml, p<0.05) with no significant difference between the former two groups (p>0.05). In addition and according to the follow up sample taken after one week, a significant increase in the expression of CD45RO was realized in the septic group. Conclusion: The surface activation markers of T-lymphocytes (CD45RA/ CD45RO, CD45RO), neutrophil activation marker (CD11b) and soluble TNF receptor 1 are useful early indicators of neonatal sepsis, and are superior to the hematological scoring system and CRP in the early detection of the disease.