Case Control Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Feb 26, 2021; 9(6): 1259-1270
Published online Feb 26, 2021. doi: 10.12998/wjcc.v9.i6.1259
New indicators in evaluation of hemolysis, elevated liver enzymes, and low platelet syndrome: A case-control study
Su-Ya Kang, Yun Wang, Li-Ping Zhou, Hong Zhang
Su-Ya Kang, Yun Wang, Li-Ping Zhou, Department of Obstetrics, Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Suzhou 215002, Jiangsu Province, China
Hong Zhang, Department of Gynecology and Obstetrics, The Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu Province, China
Author contributions: Kang SY, Wang Y, Zhou LP and Zhang H designed the research study; Kang SY, Wang Y and Zhou LP collected and analyzed the data; Kang SY wrote the manuscript; Zhang H reviewed the writing; All authors have read and approved the manuscript.
Supported by the People’s Well-being Project of Suzhou City, No. SS201710; the Clinical Expert Team Introduction Project of Suzhou City, No. SZYJTD201709; and the Research Project on Maternal and Child Health of Jiangsu Province, No. F202045.
Institutional review board statement: The study was reviewed and approved by the Ethics Committee of Suzhou Affiliated Hospital of Nanjing Medical University [approval No. (2019)118].
Informed consent statement: All gravidae involved gave informed written consent.
Conflict-of-interest statement: No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. The authors declare that there is no conflict of interest.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Li-Ping Zhou, BSc, Doctor, Department of Obstetrics, Suzhou Affiliated Hospital of Nanjing Medical University, Suzhou Municipal Hospital, No. 206 Daoqian Street, Gusu District, Suzhou 215002, Jiangsu Province, China. zhoulpszslyy@163.com
Received: September 8, 2020
Peer-review started: September 8, 2020
First decision: December 8, 2020
Revised: December 16, 2020
Accepted: January 5, 2021
Article in press: January 5, 2021
Published online: February 26, 2021
Abstract
BACKGROUND

Indices such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), platelet distribution width (PDW), and red cell distribution width (RDW) are considered new markers of the systemic inflammatory response (SIR), and have been widely implemented for the diagnosis of patients with inflammatory diseases. These new indicators have also been widely investigated in preeclampsia (PE) but less analyzed in hemolysis, elevated liver enzymes, and low platelet (HELLP) syndrome.

AIM

To compare SIR markers among HELLP patients, PE only patients, and healthy gravidae.

METHODS

This retrospective case-control study enrolled 630 cases, including 210 patients with HELLP syndrome (HELLP group), 210 patients with only PE (PE group) and 210 healthy gravidae (control group). The three groups were matched by age, parity, status of assisted reproduction, and multiple pregnancies. Birthweight, gestational age at complete blood count collection, gestational age at delivery, mode of delivery, etc. were recorded. The main indices as NLR, PLR, MPV, PDW, and RDW among the groups were compared, as well as some secondary outcomes including neutrophil, platelets, and hemoglobin.

RESULTS

The NLR (6.4 vs 4.3 vs 3.5), MPV (11.9 vs 11.2 vs 10.7), PDW (16.4 vs 13.3 vs 14.2), leukocyte (12.4 × 109/L vs 9.7 × 109/L vs 8.7 × 109/L) and neutrophil count (9.9 × 109/L vs 7.3 × 109/L vs 6.1 × 109/L) were highest in the HELLP group, lower in the PE group, and lowest in the control group. Both the overall comparisons between the three groups (all bP < 0.01) and pairwise comparisons between every two groups elicited statistically significant differences (all dP < 0.01, except control vs PE: cP < 0.05 in PDW). The average lymphocyte counts were 1.4 (1.1, 2.0) × 109/L in the HELLP group, 1.6 (1.3, 2.0) × 109/L in the PE group and 1.7 (1.4, 2.0) × 109/L in the control group. The overall comparison of lymphocyte count within the three groups had statistically significant differences (P = 0.000). The pairwise comparisons between every two groups demonstrated that the HELLP group had a lower lymphocyte count than both the PE (P = 0.019) and control groups (P = 0.000), but the difference between the PE and control groups was not statistically significant (P = 0.432). The overall comparisons on platelet counts and the PLR among these three groups also showed statistically significant differences (both P = 0.000), from low to high being those in the HELLP group (43.4 × 109/L, 64.0), control group (180.5 × 109/L, 103.6) and PE group (181.5 × 109/L, 112.8). Pairwise comparisons of neither index displayed statistically significant differences between the PE and control groups (both P > 0.05), while the differences in the two indices between the HELLP group and the two other groups were still statistically significant (all P = 0.000). RDW values were highest in the HELLP group (14.5% [13.6, 15.3]), lower in the control group (14.1% [13.5, 14.8]) and lowest in the PE group (13.9% [13.4, 14.9]). The difference between the PE and control group did not show statistical significance (P = 1.000), while RDW values in the HELLP group were higher than those in the other two groups (cP < 0.05 vs control, dP < 0.01 vs PE).

CONCLUSION

SIR markers such as NLR, RDW, MPV, and PDW were increased and PLR was decreased in HELLP. These SIR markers may become new indicators in the evaluation of HELLP syndrome.

Keywords: Hemolysis, elevated liver enzymes, and low platelet syndrome, Neutrophil-to-lymphocyte ratio, Platelet-to-lymphocyte ratio, Mean platelet volume, Platelet distribution width, Red cell distribution width

Core Tip: Systemic inflammatory response (SIR) markers including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), platelet distribution width (PDW) and red cell distribution width (RDW) have been widely investigated in preeclampsia (PE) and less analyzed in hemolysis, elevated liver enzymes, and low platelet (HELLP) syndrome. In this retrospective case-control study, SIR markers were compared among HELLP/PE patients and healthy gravidae. NLR, RDW, MPV and PDW were increased and PLR was decreased in HELLP syndrome. These parameters may become predictive and prognostic indicators and useful additions to the current diagnostic standard of HELLP syndrome, if confirmed by further more studies.