To the Editor:

We read with great interest the recent article by Okogbule-Wonodi et al. (1) about whether Ureaplasma respiratory tract colonization of preterm infants <33 wk gestation is associated with an increased risk for necrotizing enterocolitis (NEC). The authors evaluated 368 infants <33 wk gestation with one or more tracheal or nasopharyngeal aspirates for Ureaplasma culture and PCR obtained during the first week of life. They stated that NEC was confirmed in 29 of 368 (7.9%) of the combined cohorts, and the incidence of NEC was 2.2-fold higher in Ureaplasma-positive (12.3%) than Ureaplasma-negative (5.5%) infants <33 wk and 3.3-fold higher in Ureaplasma-positive (14.6%) than Ureaplasma-negative (4.4%) infants ≤28 wk. In addition, cord serum IL-6 and IL-1β concentrations were significantly higher in Ureaplasma-positive than in Ureaplasma-negative NEC-affected infants, and so, the authors suggested that Ureaplasma may be a factor in NEC pathogenesis in preterm infants by contributing to intestinal mucosal injury and/or altering systemic or local immune responses.

We have recently completed a study concerning effects of Ureaplasma respiratory tract colonization and its management on development of chronic lung disease (unpublished data). When we evaluated 224 enrolled infants who were <32 wk and seeked for Ureaplasma respiratory colonization with one or more tracheal or nasopharyngeal aspirates for Ureaplasma culture, we could not demonstrate any relationship between Ureaplasma colonization and NEC development (Table 1), which is similar to previous published study by Perzigian et al. (2). Two important factors, which were associated with NEC stage ≥2 development, were late-onset proven sepsis, volume of red blood cell transfusion, and cord serum IL-6 (Table 1). Multivariate logistic regression analysis revealed that there was only significant association between the red blood cell transfusion and NEC development (OR, 1.4; 95% CI, 1.18–1.74; p = 0.01). Although our results shows similarity with study by Okogbule-Wonodi et al. (1) in high cord serum IL-6 levels and we agree with authors on its possible association with NEC development, it is obvious that authors did not investigate the relationship between red cell transfusion and NEC development. We know that in addition to our results, some recent trials demonstrated the impressive association between transfusion and NEC development (3,4), and we suggest that Okogbule-Wonodi et al. (1) should reevaluate their patients from this point.

Table 1 The relation of clinical variables with necrotizing enterocolitis development
Full size table