Platelet-to-Lymphocyte Ratio (PLR) Is Associated with Immune Thrombocytopenia (ITP) Recurrence: A Retrospective Cohort Study

Evaluation of the hematological inflammatory parameters in the patients with immune thrombocytopenic purpura: A case-control study

Background and Aims

Inflammation is one of the immune thrombocytopenic purpura (ITP)'s aggravating elements due to inflammatory cells' function. This study aims to identify and evaluate hematological inflammatory parameters, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and hemoglobin-to-platelet ratio (HPR), in patients with ITP compared to the control group.

Methods

We retrospectively analyzed the profile of 190 ITP patients from August 2019 to January 2021 at Imam Reza Hospital of Mashhad, Iran, along with 100 healthy individuals who had no ITP-related clinical or laboratory symptoms. Immune cell counts, NLR, PLR, and HPR were calculated using the complete blood count at the time of diagnosis and after the treatment. The results were analyzed through MedCalc, SPSS software, and the receiver operating characteristic curve.

Results

The result showed that white blood cell (WBC) and neutrophil counts were higher in ITP patients (WBC: p: 0.001, neutrophil: p: 0.001), and conversely, platelet and lymphocyte counts were higher in the control group compared to ITP patients (platelets: p: 0.001, lymphocytes: p: 0.001). The indices analysis between the two groups revealed that NLR was significantly increased in ITP patients (p: 0.001), but PLR was significantly reduced in ITP patients (with the mean platelet count of 23.44 ± 35.26 × 109/L) compared to the control group (with the mean platelet count of 234.04 ± 55.88 × 109/L). The HPR index also significantly increased in ITP patients (p: 0.001).

Conclusion

An increase in NLR, PLR, and a decrease in HPR can be considered a valuable diagnostic algorithm in patients with ITP.

Predictive effects of platelet-to-lymphocyte ratio on neonatal thrombocytopenia in primary immune thrombocytopenic mothers: a retrospective cohort study

BACKGROUND

Primary immune thrombocytopenia (ITP) can increase the risk of neonatal thrombocytopenia (NT). This study aimed to investigate the key factors for predicting the risk of NT.

METHODS

Data were retrospectively collected from all pregnant women with ITP from 2015 to 2021. Newborns were divided into two groups according to the presence or absence of NT. The parameters between the two groups were then compared. Next, the correlation between maternal platelet-to-lymphocyte ratio (PLR) and neonatal platelet count was analyzed by logistic regression and generalized additive model. Additionally, the relationships among the platelet counts of siblings were also determined.

RESULTS

A total of 147 maternal cases were included. NT was observed in 46 (31.72%) neonates. A history of previous children with NT appeared to have predictive value for NT (OR 16.484, 95% CI 2.212-122.858, P < 0.001), as the nadir gestational platelet (OR 0.958, 95% CI 0.93-0.988, P < 0.001). Correlation analysis of platelet count on postnatal day 1 and the nadir platelet count in 36 sibling neonates showed a positive correlation (r=0.684, P<0.001; r=0.900, P<0.05). PLR was divided into 3 groups via tertiles, and the incidence of NT was dramatically higher in the group with lower PLR during the second and third trimesters than in the other two groups (48.5% vs 33.3% vs 22%, P<0.05; 50% vs 21.3% vs 26.7%, P<0.001). Moreover, the risk of NT was markedly higher in the first trimester (PLR < 78.51; OR 0.975, 95% CI 0.951-0.999, P<0.05) and the second trimester (PLR < 20.41; OR, 0.899, 95% CI 0.820-0.985, P<0.05) compared to the third trimester.

CONCLUSION

Our findings suggest that a history of previous children with NT is a significant factor for predicting NT in subsequent pregnancies. PLR in the first, second and third trimesters can also be used as a reference to predict NT risk.

Platelet Parameters and Risk of Hypertension disorders of Pregnancy: a Propensity Score Adjusted Analysis

While the role of platelets in cardiovascular diseases among the general population has been widely reported, evidence is inconsistent regarding the association between platelet indices with hypertension in pregnant women. In this study, we explored the associations between platelet parameters before 20 gestational weeks, an understudied period, with hypertensive disorders of pregnancy (HDP), including preeclampsia/eclampsia (PEEC) and gestational hypertension (GH). Based on the Born in Guangzhou Cohort Study, 12053 singleton pregnant women with platelet parameters, including platelet count (PC), mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) measured at 14-19 gestational weeks were included. Conventional multivariable adjustment and propensity score analysis were used to control for confounders. The restricted cubic spline showed that the risk of PEEC increased linearly for PC, and non-linearly for PCT. For GH, the risk increased linearly for PC, MPV, and PCT, and non-linearly for PDW. When these indices were categorized into quintiles, women with higher PC and PCT were associated with increased risk of both PEEC and GH. Women with MPV exceeding the second quintile (≥ 8.8 fL) had a greater risk for GH, but not for PEEC. When HDP was classified into two groups (early- vs late-onset) based on the occurrence time, significant associations persisted for early-onset PEEC, early-onset GH, and late-onset GH. In conclusion, increased PC and PCT before 20 weeks of gestation were both associated with higher risk of PEEC and GH, while elevated MPV was only linked to GH.