Correlation between Late-onset Neutropenia, Sepsis and Associated Factors in Preterm Infants: A single center study

Background: Late onset neutropenia (neutropenia after 3 weeks of life) may be a physiological condition without need to prescribe antibiotics, G-CSF, or IVIG. We aimed to determine the association between sepsis and late onset neutropenia in very low birth weight (<1500 gm) infants.&nbsp; Methods: This study was a cross-sectional prospective study in VLBW infants that were admitted in Mahdieh Hospital in Tehran/Iran. Complete blood count (CBC) was drawn at first day of admission and then weekly intervals until discharge from the hospital. In cases with neutropenia, CRP and blood cultures were assessed and correlation between clinical sepsis or positive blood culture and CRP with neutropenia was evaluated.&nbsp; Results: 219 VLBW infants during a period of 11 weeks were studied with serial weekly CBCs. 128 (58%) neonates had normal neutrophil counts, 91 (41.6%) had neutropenia, of which 28 (30.7%) had late onset neutropenia. Mean level of WBC was 5033.07&plusmn;2037.57 cells/mm3 and mean level of ANC was 1757.75&plusmn;944.32 cells/mm3. Positive blood culture at first week of life had significant correlation with neutropenia (P=0.001), but there was no significant correlation between late onset neutropenia and positive CRP (P=0.861), clinical symptoms of sepsis (P=0.5) and bacteremia (P=0.861). There was significant correlation between anemia (P<0.001) and IVH (P<0.007) without any significant correlation with asphyxia (P<0.223) and IUGR (P<0.123) with late onset neutropenia. Conclusion: VLBW infants admitted to the NICU with late onset neutropenia without symptoms of sepsis do not need any intervention and close observation with follow-up would be the most appropriate approach.