IEIlkay Er

Ilkay Er

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Ilkay Er has a total of 50 co-authors. Here are the top co-authors by number of shared publications:

  • Medeni Arpa

    Department of Medical Biochemistry, Faculty of Medicine, Recep Tayyip Erdogan University, Rize, Türkiye

    3 shared publications
  • Ayla Günlemez

    Kocaeli University

    2 shared publications
  • Canan Baydemir

    Department of Biostatistics and Medical Informatics, Kocaeli University Faculty of Medicine, Kocaeli, Turkey

    2 shared publications
  • Ayla Gunlemez

    Department of Pediatrics, Division of Neonatology, Kocaeli University School of Medicine, Kocaeli, Turkey

    1 shared publication
  • Ayla Günlemez

    Division of Neonatology, Department of Pediatrics, Kocaeli University Faculty of Medicine, Kocaeli, Turkey

    1 shared publication
  • Ayse Engin Arisoy

    Department of Pediatrics, Division of Neonatology, Kocaeli University School of Medicine, Kocaeli, Turkey

    1 shared publication

Latest Publications

  • Open Access

    Inflammatory Indices in Preterm Infants with Hemodynamically Significant Patent Ductus Arteriosus: Early Postnatal Patterns and Treatment Response

    by Demet Türkeli, Ilkay Er, Hikmet Kıztanır, Medeni Arpa

    Background: Inflammatory mechanisms may contribute to persistent ductal patency in preterm infants with hemodynamically significant patent ductus arteriosus (hsPDA). This study evaluated early postnatal temporal patterns of complete blood count (CBC)-derived inflammatory indices in relation to ductal status and pharmacologic treatment response. Methods: This retrospective single-center study included preterm infants born at <34 weeks’ gestation who received pharmacologic treatment for hsPDA. Hematologic parameters and CBC-derived inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), pan-immune inflammation value (PIV), and immature granulocyte (IG) parameters, were assessed on postnatal days 1, 3, and 7. Results: The final cohort included 71 preterm infants with hsPDA. Over the first postnatal week, NLR and PLR peaked on day 3, MLR remained elevated, and PIV increased toward day 7. SII and SIRI showed significant temporal variation, whereas IG parameters did not. Among longitudinal changes, only ΔPIV, calculated as day 3 minus day 7 values, differed by treatment response, with a greater increase in PIV observed among non-responders. ΔPIV yielded limited discrimination for non-response (AUC = 0.646; sensitivity, 92%; specificity, 37%; cut-off, ≤110.4). Birth weight and gestational age were positively correlated with several hematologic parameters and inflammatory indices, whereas ductal status showed inverse associations with IG% on day 1 and with monocyte count and MLR on day 3. After adjustment for maturational factors and treatment type, the ΔPIV–response association was attenuated, without improved discrimination. Conclusions: CBC-derived inflammatory indices demonstrated distinct early postnatal patterns in infants with hsPDA. ΔPIV may serve as a hypothesis-generating longitudinal marker of treatment response rather than a stand-alone predictor and warrants further validation.

  • Novel ABCA12 frameshift variant in a preterm infant with harlequin ichthyosis

    by Ilkay Er, Senol Citli, Dilek Bektas, Hatice Bankoglu Yildirim, Ege Unal

  • Open Access

    The Thrombopoietic Signature of Preeclampsia: Diagnostic and Monitoring Insights from the Immature Platelet Fraction

    by Ilkay Er, Senol Sentürk, Medeni Arpa, Nalan Kuruca

    Background: Preeclampsia is a major obstetric disorder characterized by platelet activation and dysregulated thrombopoiesis. While conventional platelet indices reflect platelet morphology, the immature platelet fraction (IPF) provides insight into thrombopoietic activity. This study assessed IPF discrimination at presentation and its early post-treatment change in preeclampsia while controlling for potential confounding factors. Methods: In a prospective design, demographic and laboratory parameters—particularly platelet indices—were evaluated in women with preeclampsia and normotensive pregnant controls. Measurements were obtained at diagnosis and repeated 24–48 h after treatment, including initiation of medical treatment or delivery. Logistic regression and ROC analyses were performed, adjusting for age and gestational age. Results: Sixty-four women with preeclampsia and 25 normotensive controls were included; the preeclampsia group was older (31.3 ± 5 vs. 28.4 ± 4 years), and delivery occurred in 73.4%. At diagnosis, IPF, MPV, and PDW were higher, and platelet counts were lower compared with controls. After treatment, IPF decreased markedly (ΔIPF = 3.4; p < 0.001), accompanied by reductions in MPV and PDW, while platelet counts remained unchanged in the preeclampsia group. ΔIPF showed subtype-related differences, being higher in late-onset preeclampsia. Only IPF retained an independent association with preeclampsia (OR = 27.29; p = 0.006), whereas age, platelet count, MPV, PDW, BUN, and CRP were not significant. On ROC analysis, IPF demonstrated strong diagnostic performance (AUC = 0.992; cut-off ≥4%), with 98.4% sensitivity and 100% specificity. Conclusions: Easily measurable as part of a routine complete blood count, IPF may support diagnostic evaluation and clinical monitoring, consistent with its early post-treatment decline and subtype-related patterns.

  • Open Access

    Immature Platelet Fraction as a Sensitive Biomarker in Neonatal Sepsis: Diagnostic Performance Preceding Thrombocytopenia

    by Ilkay Er, Medeni Arpa

    Background: Early and accurate diagnosis of neonatal sepsis remains a clinical challenge due to nonspecific signs and limitations of conventional biomarkers. The immature platelet fraction (IPF), a novel hematologic parameter reflecting thrombopoietic activity, has emerged as a potential early sepsis indicator. This study aimed to evaluate the diagnostic value of IPF in neonatal sepsis prior to the onset of thrombocytopenia. Methods: This prospective study enrolled neonates with early-onset sepsis (EOS), late-onset sepsis (LOS), and healthy controls. IPF, C-reactive protein (CRP), procalcitonin (PCT), and hematologic indices were measured at diagnosis and 48–72 h post-treatment. Diagnostic performance was evaluated via ROC curve analysis, and correlations between IPF and inflammatory/hematologic markers were examined. IPF levels were also compared based on blood culture results. Results: IPF levels were significantly higher in both EOS (n: 56) and LOS (n: 50) groups compared to controls (n: 44) (p < 0.001). ROC analysis showed excellent diagnostic performance, with AUCs of 0.98 (EOS) and 0.99 (LOS). Following antibiotic treatment, IPF levels declined significantly (p < 0.001), supporting its dynamic value. Strong and moderate correlations were found with MPV and CRP, respectively, and an inverse association with platelet count, but not with PCT. Moreover, IPF levels were higher in culture-positive cases compared to culture-negative ones (13.1% vs. 9.8%; p = 0.017) and exhibited diagnostic performance comparable to CRP in predicting blood culture positivity. Conclusions: This study presents original and clinically relevant data supporting IPF as a promising and practical hematologic biomarker for early detection and treatment monitoring of neonatal sepsis. Its integration into standard sepsis evaluation protocols may improve early risk stratification and clinical decision-making in neonatal intensive care settings.


  • Open Access

    Factors Affecting Lung Function in Preschool Children with a History of Transient Tachypnea of the Newborn

    by Ismail Cevik, Ilkay Er, Ayla Gunlemez

    Background: Transient tachypnea of the newborn (TTN) is a common cause of self-limiting respiratory distress in neonates. Increasing data suggest that TTN may be a risk factor for developing childhood wheezing attacks or asthma. Objectives: The aim was to evaluate lung functions in preschool children diagnosed with TTN in the neonatal period using an Impulse Oscillometry System (IOS) to assess the presence of respiratory morbidity and its contributing factors. Methods: In this prospective study, preschool children diagnosed with TTN in the neonatal period and healthy age-matched children were defined as the TTN group and control group, respectively. Impulse Oscillometry System values for resistance (R5-R20), reactance (X5-X20), resonant frequency (Z5), and reactance area (AX) were compared between both groups and within the TTN subgroups. Asthma diagnosis was determined following IOS testing using the Modified Asthma Predictive Index/ International Study of Asthma and Allergies in Childhood (ISAAC). Results: A total of 52 preschool children and 101 healthy controls participated in the study. R5 minus R20 was significantly higher, and X10 and X15 values were significantly lower in the TTN group compared to the controls. Additionally, higher R values and AX values were observed in TTN subgroups with a history of late preterm birth, noninvasive respiratory support, and maternal asthma. The rates of variable respiratory symptoms and ≥ 4 wheezing attacks in one year were 20.5% and 18%, respectively. By the end of the study, the rate of newly diagnosed asthma in the TTN group was 30.8%. Moreover, R values and Z5 were significantly higher, and X values were significantly lower in the TTN subgroup exposed to passive smoking (PS) compared to the TTN subgroup not exposed. Conclusions: Our study showed that preschool children diagnosed with TTN in the neonatal period may have peripheral airway obstruction, a known characteristic of asthma. In addition to TTN-related factors, exposure to cigarette smoke appears to negatively impact their lung function. These findings suggest that long-term medical care should be provided for these children.

  • Open Access

    Vitamin D Deficiency Prevalence in Late Neonatal Hypocalcemia: A Multicenter Study

    by Gülcan Seymen-Karabulut, Ayla Günlemez, Ayşe Sevim Gökalp, Şükrü Hatun, Fatma Kaya Narter, Mehmet Mutlu, Şebnem Kader, Demet Terek, Deniz Hanta, Emel Okulu, et al.

    Objective:Late neonatal hypocalcemia (LNH) is a common metabolic problem associated with hypoparathyroidism, high phosphate intake and vitamin D deficiency, often presenting with seizures. In this cross-sectional study, we aimed to evaluate the role of vitamin D deficiency in LNH in Turkey and to describe the characteristics of affected newborns.Methods:Conducted with a cross-sectional design and with the participation of 61 neonatal centers from December 2015 to December 2016, the study included term neonates with LNH (n=96) and their mothers (n=93). Data were registered on the FAVOR Web Registry System. Serum samples of newborns and mothers were analyzed for calcium, phosphate, magnesium, albumin, alkaline phosphatase, intact parathyroid hormone (iPTH) and 25 hydroxyvitamin D [25(OH)D] levels.Results:The median (range) onset time of hypocalcemia was 5.0 (4.0-8.0) days of age, with a male preponderance (60.4%). The median (range) serum 25(OH)D levels of the neonates and their mothers were 6.3 (4.1-9.05) and 5.2 (4.7-8.8) ng/mL, respectively. The prevalence of vitamin D deficiency (<12 ng/mL) was high in both the neonates (86.5%) and mothers (93%). Serum 25(OH)D levels of the infants and mothers showed a strong correlation (p<0.001). While the majority (93.7%) of the neonates had normal/high phosphorus levels, iPTH levels were low or inappropriately normal in 54.2% of the patients.Conclusion:Vitamin D deficiency prevalence was found to be high in LNH. Efforts to provide vitamin D supplementation during pregnancy should be encouraged. Evaluation of vitamin D status should be included in the workup of LNH.


  • Open Access

    Can Immature Platelet Fraction be an Early Predictor for Congenital Pneumonia?

    by Ilkay Er, Ceren Cetin, Canan Baydemir, Ayla Günlemez

    Timely diagnosis and treatment of congenital pneumonia are crucial. A new hematologic parameter, immature platelet fraction, has been used to gather clinical information on the prognosis of thrombocytopenia, as well as to measure inflammatory activity in adult patients. This study aimed to compare immature platelet fraction and sepsis biomarkers in late-preterm infants diagnosed as having congenital pneumonia and to evaluate its predictive value for congenital pneumonia. Late-preterms were categorized based on infectious vs. non-infectious etiology of respiratory distress. Two sets of blood samples for markers were taken at 12–24 (sample-1) and 48–72 hours (sample-2) after birth. Immature platelet fraction was measured using a Sysmex XN-3000 analyzer. From a total of 30 non-thrombocytopenic late-preterms, 16 were included in the congenital pneumonia group and 14 comprised the transient tachypnea group. The groups were comparable in terms of gestational age, birth weight, and cesarean section rate. The proportion of prolonged membrane rupture was significantly higher in the congenital pneumonia group. Values of immature platelet fraction-1, immature platelet fraction-2, and procalcitonin-2 were significantly higher in the congenital pneumonia group than in the transient tachypnea group. No significant differences were found between the groups in other biomarkers. It was determined that an immature platelet fraction-1 cut-off value of 2.9% could predict congenital pneumonia with a sensitivity of 65%, a specificity of 71.4%, a positive predictive value of 70.5%, and negative predictive value of 63.7% (area under the curve=0.724; p=0.028). Immature platelet fraction may have an early predictive role in the diagnosis of congenital pneumonia.


  • Evaluation of pulmonary functions in preschool children born late-preterm

    by Ilkay Er, Ayla Gunlemez, Zeynep Seda Uyan, Metin Aydogan, Meral Oruc, Olcay Isik, Ayse Engin Arisoy, Canan Baydemir, Ayse Sevim Gokalp

    The aim of this study was to evaluate the pulmonary functions of preschool children born late-preterm. Children aged between 3-7 years who were born at 340/7-366/7 weeks' gestation represented the target sample. Patients with a diagnosis of congenital cardiac, pulmonary and/or muscle diseases were excluded. Respiratory symptoms were evaluated using the modified asthma predictive index and International Study of Asthma and Allergies in Childhood criteria for children aged under and over 6 years, respectively. Skin prick tests were performed. Age-matched healthy controls were chosen according to the criteria proposed by the American Thoracic Society. Lung functions were evaluated using impulse oscillometry study in both groups. Data were recorded in the SPSS program. A total of 139 late-preterms and 75 healthy controls participated in the study. The mean gestational week of the late-preterms was 35.3±0.9 weeks. The main admission diagnosis to neonatal intensive care unit was respiratory distress. In the postdischarge period, 54.1% were hospitalized for pulmonary infections at least once, and 57.8% were passive smoking currently. Aeroallergen sensitivity was detected as 25.8% in the late-preterm group; 34.5% and 15.1% were diagnosed as having asthma and non-asthmatic atopy, respectively. Impulse oscillometry study parameters of R5, R10, and Z5 were higher and X10 and X15 were lower in late-preterms than in controls (p<0.05). Late-preterms with and without respiratory distress in the postnatal period revealed no statistical differences for any parameters. Our findings suggest that presence of increased peripheral airway resistance in late-preterms as compared to term-born controls.