Immature-to-total neutrophil ratio as an early diagnostic tool of bacterial neonatal sepsis

Darnifayanti Darnifayanti; Guslihan Dasa Tjipta; Rusdidjas Rusdidjas; Bugis Mardina Lubis

doi:10.14238/pi55.3.2015.153-7

Darnifayanti Darnifayanti Department of Child Health, University of Sumatera Utara Medical School /H. Adam Malik Hospital, Medan, Indonesia
Guslihan Dasa Tjipta Department of Child Health, University of Sumatera Utara Medical School /H. Adam Malik Hospital, Medan, Indonesia
Rusdidjas Rusdidjas Department of Child Health, University of Sumatera Utara Medical School /H. Adam Malik Hospital, Medan, Indonesia
Bugis Mardina Lubis Department of Child Health, University of Sumatera Utara Medical School /H. Adam Malik Hospital, Medan, Indonesia

DOI: https://doi.org/10.14238/pi55.3.2015.153-7

Keywords: bacterial sepsis, IT ratio, blood culture, neonate, diagnostic

Abstract

Background Bacterial sepsis is the main cause of morbidity and mortality in neonates. Early diagnosis and appropriate treatment for the condition can reduce mortality rates. Blood cultures are the gold standard to diagnose bacterial sepsis, but they require 3-5 days for results, whilst the disease may progress rapidly in neonates. Examination of immature-to-total neutrophil ratio (I/T ratio) in peripheral blood smears is a quicker and less expensive method to diagnose bacterial sepsis in neonates. Some studies found the sensitivity of I/T ratio to be 88%-90% in predicting bacterial spesis.
Objective To assess the usefulness of the I/T ratio as an early diagnostic tool for neonatal bacterial sepsis.
Methods This cross-sectional study was conducted from February to March 2011. Subjects were collected by consecutive sampling. Fifty-three neonates suspected to have bacterial sepsis in the Perinatology Unit at H. Adam Malik Hospital were included. Subjects underwent routine blood examinations, C-reactive protein level measurements, blood cultures, and peripheral blood smears. All statistical analyses were conducted with SPSS (version 16.0 for Windows).
Results Of the 53 subjects, 26 had bacterial sepsis based on blood cultures. The I/T ratio had a sensitivity of 88.46%, specificity 81.84%, positive predictive value 82.14%, and negative predictive value 88%. The receiver operating characteristic curve showed a cut-off point of 83.3 (95%CI 71.3 to 95.3)%.
Conclusion The I/T ratio may be a good alternative to blood cultures as an early indicator of bacterial neonatal sepsis, as it is faster, less expensive and has good sensitivity and specificity.

References

Amirullah A. Sepsis pada bayi baru lahir. In: Kasim SM, Yunanto A, Dewi R, Sarosa IG, Usman A, editors. Buku ajar neonatologi. Jakarta: Ikatan Dokter Anak Indonesia; 2008. p. 170-87.

Gomella TL. Infectious disease. In: Gomella TL, Cuningham MD, Eyal FG, Zenk KE, editors. Neonatology: management, procedures, on-call problems, disease and drugs. New York: Lange, McGraw-Hill; 2004. p. 434-40.

Aulia D, Sanjaya AI, Timan IS. The use of immatane to total neutrophil (IT) ratio to detect bacteriemia in neonatal sepsis. J Lab Med Quality Assurance. 2003;25:237-42.

Jackson GL, Engle WD, Sendelbach DM, Vedro DA, Josey S, Vinson J, et al. Are complete blood cell count useful in the evaluation of asymptomatic neonates exposed to suspected chorioamnitis? Pediatrics. 2004;113:1173-80.

Mishra UK, Jacobs SE, Doyle LW, Garland SM. Newer approaches to the diagnosis of early onset neonatal sepsis. Arch Dis Child Fetal Neonatal Ed. 2006;91:F208-12.

Klinger G, Levy I, Sirota L, Boyko V, Lerner-Geva L, Reichman B, et al. Outcome of early-onset sepsis in national cohort of very low birth weight infants. Pediatrics. 2010;125:e736-40.

Osrin D, Vergnano S, Costello A. Serious bacterial infections in newborn infants in developing countries. Curr Opin Infect Dis. 2004;17:217-24.

Phillip AG, Hewitt JR. Early diagnosis of neonatal sepsis. Pediatrics. 1980;65:1036-41.

Rodwell RL, Leslie AL, Tudehope DI. Early diagnosis of neonatal sepsis using a hematologic scoring system. J Pediatr. 1988;112:761-7.

Stoll BJ, Hansen N, Fanaroff A, Wright LL, Carlo WA, Ehrenkranz RA, et al. Changes in pathogens causing earlyonset sepsis in very-low-birth-weight infants. N Engl J Med. 2002;347:240-7.

Saez-Llorens X, Vargas S, Guerra F, Coronado L. Application of new sepsis definitions for evaluate outcome of pediatric patients with severe systemic infections. Pediatr Infect Dis J. 1995:14;557-60.

Baltimore RS, Huie SM, Meek JI, Schuchat A, Oâ€™Brien KL. Early-onset neonatal sepsis in the era of group B streptococcal prevention. Pediatrics. 2001;108:1094-8.

Stoll BJ. Infections of the neonatal. In: Behrman RE, Kiegman RM, Jenson HB, Stanton BF, editors. Nelson textbook of pediatrics. 18th ed. Philadelphia: Saunders Company; 2007. p. 794-811.

Manroe BL, Rosenfeld CD, Weinberg AG, Browne R. The differential leukocyte count in the assessment and outcome of early-onset neonatal group B streptococcal disease. J Pediatr. 1977;91:632-7.

Franz AR, Kron M, Pohlandt F, Steinbach G. Comparison of procalcitonin with interleukin 8, C-reactive protein and differential white blood cell count for the early diagnosis of bacterial infections in newborn infants. Pediatr Infect Dis J. 1999;18:666-71.