Can plateletcrit, an underestimated platelet parameter, be related with preterm labour?

Platelet count in preeclampsia: a systematic review and meta-analysis

OBJECTIVE

Many studies have reported the association between platelets and preeclampsia. However, sample sizes were small, and their findings were inconsistent. We conducted a systematic review and meta-analysis to evaluate the association in pooled samples and in detail.

DATA SOURCES

A systematic literature search was performed using Medline, Embase, ScienceDirect, Web of Science, Cochrane Library, NICHD-DASH, LILACS, and Scopus from inception to April 22, 2022.

STUDY ELIGIBILITY CRITERIA

Observational studies comparing platelet count between women with preeclampsia and normotensive pregnant women were included.

METHODS

The mean differences with 95% confidence interval in platelet count were calculated. Heterogeneity was assessed using I2 statistics. Sensitivity and subgroup analyses were conducted. Statistical analysis was performed using RevMan 5.3 and ProMeta 3 software.

RESULTS

A total of 56 studies comprising 4892 preeclamptic and 9947 normotensive pregnant women were included. Meta-analysis showed that platelet count was significantly lower in women with preeclampsia than in normotensive controls (overall: mean difference, -32.83; 95% confidence interval, -40.13 to -25.52; P<.00001; I2=92%; mild preeclampsia: mean difference, -18.65; 95% confidence interval, -27.17 to -10.14; P<.00001; I2=84%; severe preeclampsia: mean difference, -42.61; 95% confidence interval, -57.53 to -27.68; P<.00001; I2=94%). Significantly lower platelet count was also observed in the second trimester (mean difference, -28.84; 95% confidence interval, -44.59 to -13.08; P=.0003; I2=93%), third trimester (mean difference, -40.67; 95% confidence interval, -52.14 to -29.20; P<.00001; I2=92%), and before the diagnosis of preeclampsia (mean difference, -18.81; 95% confidence interval, -29.98 to -7.64; P=.009; I2=87%), but not in the first trimester (mean difference, -15.14; 95% confidence interval, -37.71 to 7.43; P=.19; I2=71%). Overall, the pooled sensitivity and specificity of platelet count were 0.71 and 0.77, respectively. The area under the curve was 0.80.

CONCLUSION

This meta-analysis confirmed that platelet count was significantly lower in preeclamptic women, irrespective of severity and presence or absence of associated complications, even before the onset of preeclampsia and in the second trimester of pregnancy. Our findings suggest that platelet count may be a potential marker to identify and predict preeclampsia.

Association of subclinical markers of inflammation with preterm premature rupture of membranes and adverse neonatal results: a case control study

AIM

The study aims to investigate the relationship between subclinical inflammatory factors, which are known to be closely related to inflammation, with preterm premature rupture of membranes (PPROM) and adverse postpartum outcomes.

MATERIALS AND METHODS

The case control type study was conducted between January 1, 2021, and January 2022. 525 pregnant women, including 272 PPROM and 253 normal patients, were added to the study.

RESULTS

There was a positive relationship between PPROM and PCT (platelet crit), MPV (mean platelet volume), NLR (neutrophil-to-lymphocyte ratio), and MLR (monocytes to lymphocyte ratio) values. ROC analysis, PCT > 0.19, MPV > 8.78, NLR > 2.82, and MLR > 0.24 were significantly related to improved risk of PPROM (P < 0.05). In logistic regression analysis, a one-unit rise in PCT resulted in a 3.9-fold rise in RDS risk and a one-unit increase in NLR resulted in a 1.6-fold significant rise in sepsis risk (p < 0.05).

CONCLUSION

NLR and PCT parameters were found to be related to adverse neonatal outcomes.

The Association of Inflammatory Biomarker of Neutrophil-to-Lymphocyte Ratio with Spontaneous Preterm Delivery: A Systematic Review and Meta-analysis

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR), as an inflammatory biomarker, has been investigated in several studies for early prediction of preterm delivery. However, their findings seem to be controversial. Thus, this systematic review and meta-analysis was conducted to evaluate the role of NLR in predicting preterm delivery as compared to term controls.

METHODS

PubMed, Web of Science, Embase, Scopus, and Google Scholar were systematically searched from inception up to December 2020. Interstudy heterogeneity was assessed using Cochrane's Q test and the I 2 statistic. The random-effects model was employed to pool the weighted mean differences (WMDs) and the corresponding 95% confidence intervals (CIs).

RESULTS

Out of a total of 4369 recodes, fifteen articles including 3327 participants were enrolled. The meta-analysis finding using the random-effects model produced a pooled estimate suggesting a significantly higher NLR (WMD = 1.23, 95% CI: 0.40-2.07) in women with preterm delivery (P = 0.01). We found significant heterogeneity across the included studies (P < 0.001, I 2 = 92.33%). However, interstudy heterogeneity exists mainly due to differences in the definition of preterm delivery (I 2 = 0.0%). In the metaregression analysis, there was no significant effect of publication year (B = -0.288, P = 0.088), total sample size (B = -0.002, P = 0.276), and the mean age of cases (B = -0.06, P = 0.692) on the association between NLR and preterm delivery.

CONCLUSION

The results of this meta-analysis revealed that the NLR value is higher in patients with preterm delivery. The NLR could be a useful biomarker for predicting preterm delivery; however, further prospective case-control studies are required to produce stronger evidence.

How do platelet-to-lymphocyte ratio and neutrophil-to-lymphocyte ratio change in women with preterm premature rupture of membranes, and threaten preterm labour?

The aim of the study was to investigate peripheral blood platelets, neutrophils and lymphocytes counts in women with preterm premature rupture of membranes (PPROM) and threatened preterm labour (TPL) compared with gestation-matched controls in order to learn how they change. This study was conducted on 60 women with PPROM, 50 women with TPL and 47 healthy pregnant women. Laboratory parameters (including complete blood count, C-reactive protein (CRP)) of all the participants were recorded. The neutrophil-to-lymphocyte ratio (NLR) values were significantly higher in PPROM group than TPL group and healthy control group (6.1 ± 3.9, 4.4 ± 1.7, 4.4 ± 2.2, p = .007, p = .018, respectively). At a cut-off level of 5.14, NLR accurately predicted occurrence of neonatal sepsis (AUC =  0.717 (95% confidence interval 0.610-0.824), p = .001) with sensitivity and specificity rates of 69.7% and 72.0%, respectively. In the management of the patients with PPROM, NLR can be used as a more cost-effective method than other blood parameters that require the use of a kit.IMPACT STATEMENTWhat is already known on this subject? There is only one study in the literature evaluating blood count parameters (such as platelet-to-lymphocyte ratio (PLR), NLR) in PPROM pregnancies. That study demonstrated PLR and NLR were both higher in the PPROM group.What do the results of this study add? The present study demonstrates that only NLR is higher in the PPROM group. Furthermore, we have also demonstrated distinctively that NLR can predict occurrence of neonatal sepsis.What are the implications of these findings for clinical practice and/or further research? High values of NLR may be useful for predicting adverse outcomes in PPROM and TPL patients as a cost-effective method. Further studies are needed to determine whether these parameters can be used to predict if a pregnant woman who is at risk of preterm labour will result in adverse perinatal outcome.

Prediction of Preterm Birth: Maternal Characteristics, Ultrasound Markers, and Biomarkers: An Updated Overview

There is not a single or combined screening method for preterm birth with high sensitivity which will truly identify the women at risk for preterm birth while also with high specificity to prevent unnecessary interventions and high treatment costs. Measurement of cervical length is the most cost-effective method that is used in clinical practice. Bedside tests have also been developed for detecting markers like fetal fibronectin, insulin-like growth factor binding protein-1 (IGFBP-1), interleukin-6, and placental alpha-macroglobulin-1. Taking the maternal history, health condition, and sociodemographical factors into consideration is recommended. Ultrasound markers apart from cervical length measurements as uterocervical angle and placental strain ratio are studied. Investigations on metabolomics, proteomics, and microRNA profiling have brought a new aspect on this subject. Maybe in the future, with clear identification of women at true risk for preterm birth, development of more effective preventive strategies will not be unfeasible.

Platelet-to-lymphocyte ratio: A new inflammatory marker for the diagnosis of preterm premature rupture of membranes

Objective:

Preterm premature rupture of membranes (PPROM) is closely related with maternal and fetal complications. Therefore, early diagnosis is extremely important to provide maternal and fetal well-being. Many inflammatory markers have been evaluated for their ability to diagnose membrane rupture at early stages. We aimed to investigate the relationship between the platelet-to-lymphocyte ratio (PLR) and preterm premature membrane rupture.

Material and Methods:

In this study, 121 pregnant women with PPROM and 96 age-matched pregnant women with spontaneous preterm labor who were admitted to our hospital between January 2014 and December 2015 were enrolled. Demographic data, complete blood cell count results, and neonatal outcomes were recorded.

Results:

The neutrophil and platelet counts were higher in the PPROM group (9948.4±3393.2 vs. 7466.1±1698.5/mm³ and 244.5±60 vs. 210.6±64.8/mm³, respectively, p<0.001). The PLR and neutrophil-to-lymphocyte ratios (NLR) were both significantly higher in the PPROM group (p<0.001). Correlation analysis revealed that the PLR was positively correlated with the NLR (r=0.10, p=0.031). The ability of the PLR to diagnose preterm premature rupture of membranes was evaluated using an ROC curve. The sensitivity and specificity of the PLR was 57.8% and 73.7%, respectively, at a threshold >117.14 (p<0.001).

Conclusion:

The PLR might be a cost effective, easy to use, and practical marker for the early diagnosis of PPROM, which can help to determine the appropriate waiting time for delivery and provide maternal and fetal well-being.

Plateletcrit in Ocular Pseudoexfoliation Syndrome

PURPOSE

The aim of this study was to compare all platelet markers, especially plateletcrit (PCT, total platelet mass), in patients with and without ocular pseudoexfoliation (PEX) syndrome.

METHODS

One hundred six patients with ocular PEX syndrome (study group) and 106 individuals without ocular PEX syndrome (control group) were enrolled in this retrospective case-control study. The biochemical/hematological laboratory results of both the study and control groups were analyzed by a clinician blinded to the group assignments. The main outcome measures were the PCT, platelet count (PLT), mean platelet volume (MPV), and platelet distribution width (PDW).

RESULTS

The mean PCT in the study and control groups were 0.206%±0.520% and 0.171%±0.410%, respectively (P<0.001), and the mean PDW in the study and control groups were 16.12%±1.21% and 14.68%±1.40%, respectively (P<0.001). There were no differences in the MPV or mean PLT (P=0.138 and P=0.055, respectively). The PCT cutoff value was 0.180 (area under the receiver operating characteristics curve, 0.706; P<0.001; 65% sensitivity; 74% specificity).

CONCLUSIONS

The PCT and PDW were significantly higher in patients with than without ocular PEX syndrome. These increased parameters may cause microvascular blood flow resistance and the heightened inflammatory response caused by excessive platelet activity, as with other cardiovascular diseases, and may also decrease aqueous humor outflow in ocular PEX syndrome.