Thrombocytopenia as Type 1 ROP Biomarker: A Longitudinal Study

Abstract

This study aimed to prospectively evaluate the association between the appearance and evolution of retinopathy of prematurity (ROP) and selected blood parameters, focusing on platelets count. In total, 157 preterm consecutive babies screened for ROP were included and classified in: ROP necessitating treatment (group ROP1), ROP regressed without therapy (group ROP2) and no ROP (group no-ROP), divided in two phases for each group depending on gestational age. Blood parameters were weekly gathered and referred to postmenstrual age, ROP severity and phase. Platelet count mean values were statistically lower (p < 0.001) during both phases in ROP1 group (179 × 109/L vs. 213 × 109/L in phase 1 and 2, respectively) vs. other groups (ROP2: 286 × 109/L vs. 293 × 109/L; no ROP: 295 × 109/L vs. 313 × 109/L). Platelet count at birth <181 × 109 was statistically associated with Type 1 ROP development and evolution (sensibility = 76.47%, 95% confidence interval 60.0–87.6; specificity = 66.12%, 95% confidence interval 57.3–73.9). In ROP 1 group, a platelets count mean value “spike” (392.6 × 109/L) was documented at 36 weeks of corrected gestational age, preceding the need for treatment performed at a median of 38.1 ± 3.2 weeks. Early birth thrombocytopenia is confirmed as a biomarker of development and progression of ROP requiring treatment. The increase of platelets count at 35–37 weeks of corrected gestational age can be considered a possible clinical biomarker anticipating Type 1 ROP progression in preterm infants.

Association of platelet deficiency with severe retinopathy of prematurity: a review

“…In the present review, studies that defined subjects with stage 2 ROP or less as cases were explicitly excluded, to avoid confusion when interpreting the results (Figure 1). However, the definition of cases still differed significantly among studies, including type I ROP, 15,18,20,22,24,27,28,33 AP-ROP, 19 or ROP requiring treatment, encompassing both type I and AP-ROP, 16,21,23,26,[29][30][31] or at least stage 3 ROP. 25,31,32 Likewise, the definition of controls differed largely, including infants without ROP, 24,25,[27][28][29][30]32,33 ROP up to stage 1, 15,18,20,22,23 ROP up to stage 2, 19,31 or infants with less severe ROP, presumably including up to stage 3 without plus disease, namely type II ROP, 16,26 or even infants with unspecified ROP stage.…”

“…However, the definition of cases still differed significantly among studies, including type I ROP, 15,18,20,22,24,27,28,33 AP-ROP, 19 or ROP requiring treatment, encompassing both type I and AP-ROP, 16,21,23,26,[29][30][31] or at least stage 3 ROP. 25,31,32 Likewise, the definition of controls differed largely, including infants without ROP, 24,25,[27][28][29][30]32,33 ROP up to stage 1, 15,18,20,22,23 ROP up to stage 2, 19,31 or infants with less severe ROP, presumably including up to stage 3 without plus disease, namely type II ROP, 16,26 or even infants with unspecified ROP stage. 21 All these variations may affect the difference in the severity of ROP between the studied groups and therefore may have an impact on the outcome of interest.…”

“…All the clinical studies were observational, of which one case series, 17 eight retrospective case-control studies with or without matching, 15,[18][19][20][21][22][23][24] eight retrospective cohort studies, 16,[25][26][27][28][29][30][31] and two prospective cohort studies. 32,33 If studies comprised three groups, 24,27,29,30,33 comparative data were only collected on cases with ROP requiring treatment and the group of infants without ROP.…”

“…Over the last decade, a number of primary, observational, cohort or case-control studies, were conducted to evaluate associations between platelet parameters and severe ROP. 15,16,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]…”

Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth

“…Therefore, there is an urgent need of standardizing evaluation criteria and identifying early indicators for ROP development. In this respect, a recent retrospective Italian study reported that early platelet counts were significantly reduced in newborns who later developed severe ROP which required treatment, but not in those who never developed ROP [ 48 , 49 ] suggesting that platelet count may be used to detect in advance premature infants prone to ROP development. Recently, a new prediction model for ROP, the Postnatal Growth and ROP (G-ROP), which was originally developed in 2018 and validated in a North American cohort of preterm infants [ 50 ], has been also validated in Italy [ 51 ].…”