Role of Platelet to Lymphocyte Ratio as a Biomedical Marker for the Pre-Operative Diagnosis of Acute Appendicitis

Blood biomarkers to distinguish complicated and uncomplicated appendicitis in pediatric patients

BACKGROUND/PURPOSE

Acute appendicitis (AA) stands as the most prevalent cause of acute abdominal pain among children. The potential for morbidity escalates significantly when uncomplicated appendicitis (UA) progresses to complicated appendicitis (CA), which can encompass gangrenous, necrotic, or perforated appendicitis. Consequently, establishing an early and accurate diagnosis of AA, and effectively differentiating CA from UA, becomes paramount. This study explores the diagnostic utility of various blood biomarkers for distinguishing CA from UA in pediatric patients.

METHODS

We conducted a retrospective review of medical records pertaining to pediatric patients who underwent surgery for AA. Patients were categorized as either having UA or CA based on histopathological examination of the appendix. The data collected and analyzed included demographic information, white blood cell (WBC) count, neutrophil proportion, lymphocyte proportion, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and C-reactive protein (CRP) levels upon admission.

RESULTS

Among the 192 pediatric patients who underwent surgery for AA, 150 were diagnosed with UA, while 42 were diagnosed with CA. The CA group exhibited significantly higher neutrophil proportions, NLRs, PLRs, and CRP levels, alongside lower lymphocyte proportions (all p < 0.01) compared to the UA group. Receiver operating characteristic (ROC) curve analysis disclosed that CRP exhibited the highest specificity, sensitivity, and positive and negative predictive values for predicting CA.

CONCLUSION

CRP emerges as a valuable biomarker for differentiating complicated appendicitis from uncomplicated appendicitis.

Diagnostic value of laboratory parameters for complicated appendicitis: A two‑center study

There are two types of treatment for acute appendicitis (AA): surgery and antibiotic therapy. Some patients with complex appendicitis are treated with surgery; however, for uncomplex appendicitis, most could be treated effectively with antibiotics instead. How to distinguish complex appendicitis from uncomplex appendicitis before surgery is currently unknown. The present study aimed to assess the efficacy of the laboratory parameters to diagnose complicated appendicitis. Data from 1,514 cases with acute appendicitis who were admitted to Beijing Tsinghua Changgung Hospital and Beijing Aerospace General Hospital (both Beijing, China) from January 2016 to September 2021 were retrospectively analyzed. All cases were divided into uncomplicated and complicated appendicitis. Independent variables were analyzed by uni- and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curve analysis was used to identify significant parameters in the multivariate logistic regression analysis. Cut-off values, sensitivity, specificity and accuracy with area under the curve (AUC)>0.600 were considered significant parameters. Significant differences were found in age (P<0.001), body temperature (P<0.001), white blood cell (WBC) count (P<0.001), C-reactive protein (CRP; P<0.001), neutrophil count (P<0.001), neutrophil-to-lymphocyte ratio (NLR, P=0.019), platelet-to-lymphocyte ratio (PLR, P<0.001), platelet count (P<0.001), coefficient of variation (CV) and standard deviation (SD) of red blood cell distribution width (RDW); both P<0.001), mean platelet volume (MPV, P<0.001) and total (P<0.001) and direct bilirubin (P<0.001) between the two groups. CRP, neutrophil count, NLR, PLR, platelet count, RDW-CV, RDW-SD, MPV and direct bilirubin levels were found as the independent variables to diagnose complicated appendicitis. In patients with acute appendicitis, CRP >22.95 mg/l, NLR >5.7, serum direct bilirubin >6.1 mmol/l and RDW-SD>17.7 fl were significantly associated with complicated appendicitis.

A different way to diagnosis acute appendicitis: machine learning

<b><br>Indroduction:</b> Machine learning is a branch of artificial intelligence based on the idea that systems can learn from data, identify patterns, and make decisions with minimal human intervention.</br> <b><br>Aim:</b> Our aim is to predict acute appendicitis, which is the most common indication for emergency surgery, using machine learning algorithms with an easy and inexpensive method.</br> <b><br>Materials and methods:</b> Patients who were treated surgically with a prediagnosis of acute appendicitis in a single center between 2011 and 2021 were analyzed. Patients with right lower quadrant pain were selected. A total of 189 positive and 156 negative appendectomies were found. Gender and hemogram were used as features. Machine learning algorithms and data analysis were made in Python (3.7) programming language.</br> <b><br>Results:</b> Negative appendectomies were found in 62% (n = 97) of the women and in 38% (n = 59) of the men. Positive appendectomies were present in 38% (n = 72) of the women and 62% (n = 117) of the men. The accuracy in the test data was 82.7% in logistic regression, 68.9% in support vector machines, 78.1% in k-nearest neighbors, and 83.9% in neural networks. The accuracy in the voting classifier created with logistic regression, k-nearest neighbor, support vector machines, and artificial neural networks was 86.2%. In the voting classifier, the sensitivity was 83.7% and the specificity was 88.6%.</br> <b><br>Conclusions:</b> The results of our study show that machine learning is an effective method for diagnosing acute appendicitis. This study presents a practical, easy, fast, and inexpensive method to predict the diagnosis of acute appendicitis.</br>.

Evaluation of the performance of simple laboratory parameters used in the diagnosis of acute appendicitis

Background

Acute appendicitis (AA) is one of the most common emergency surgery.

Aim

To evaluate the performance of laboratory parameters used in the diagnosis of AA.

Subjects and Methods

There were two groups. In both groups, leukocyte (WBC), neutrophil, lymphocyte count, neutrophil/lymphocyte ratio (NLR), mean platelet volume (MPV), red cell distribution width (RDW), and platelet distribution width (PDW) values were examined in complete blood count (CBC). In addition, serum bilirubin (total bilirubin and direct bilirubin) values were examined. All laboratory parameters studied were compared to evaluate their diagnostic performance.

Results

A total of 128 people were in the AA group and 122 people were in the healthy group (control). WBC count, neutrophil count, NLR, total bilirubin, direct bilirubin, and PDW values were significantly higher in the AA group than in the control group (P value <0.05). Lymphocyte counts and MPV values in the AA group were significantly lower than in the control group (P value <0.05). The sensitivity and selectivity of the WBC and neutrophil counts in AA were 95.13%, 89.34%, 94.53%, and 93.44%, respectively. The sensitivity and selectivity of the total bilirubin values were 59.38% and 73.77%, respectively. Area under the ROC curve (AUC) values within 95% confidence interval were over 0.900 for neutrophil count, WBC count, direct bilirubin, NLR, and PDW values. AUC values for total bilirubin, lymphocyte count, RDW, and MPV values were below 0.700.

Conclusions

Diagnostic performances of the laboratory parameters were determined as follows: neutrophil count > WBC count > direct bilirubin = NLR = PDW > total bilirubin = lymphocyte count = RDW = MPV.

The role of IL-6, thiol-disulfide homeostasis, and inflammatory biomarkers in the prediction of acute appendicitis in children: a controlled study

PURPOSE

This study aimed to examine the diagnostic value of IL-6, thiol-disulfide homeostasis, complete blood count and inflammatory biomarkers in the prediction of acute appendicitis in children.

METHODS

The study was designed as a prospective and controlled study in children-the study was conducted at a tertiary referential university hospital between May 2020 and April 2021. Patients were divided between study groups and one control group (CG): 1: confirmed acute appendicitis group (AAP); 2: perforated appendicitis group (PAP); and 3: non-specified abdominal pain (NAP). The age and gender of the patients were determined. The following listed laboratory parameters were compared between groups: TOS: total oxidative status, TAS: total antioxidant status, OSI: oxidative stress index, TT: total thiol, NT (µmol/L): native thiol, DIS: disulfide, IL-6: interleukin 6, TNF-a: tumor necrosis factor-alpha, WBC: white blood cell, NEU: neutrophil, NEU%: neutrophil percentage, LY: lymphocyte, LY%: lymphocyte percentage, PLT: platelet, MPV: mean platelet volume NLR: neutrophil lymphocyte ratio, CRP: C-reactive protein, LCR: lymphocyte CRP ratio, and serum lactate.

RESULTS

The TOS level of the PAP group was found to be significantly higher than that in the AAP, NAP and control groups (p = 0.006, < 0.001 and p < 0.001). TAS, TT, and NT levels in the PAP group were significantly lower than those in the AAP, NAP and control groups. OSI was significantly higher in the PAP group than in the other groups. The TT and NT levels of the NAP group were both similar to those of the control group. Serum DIS level was similar between the AAP and PAP groups, AAP and NAP groups, and NAP and control groups. Serum IL-6 and TNF-α levels were found to be significantly higher in the PAP group compared to those in all groups. The WBC, NEU, and NEU% values were found to be significantly higher in the PAP group than those in the NAP and control groups, while LY and LY% values were found to be significantly lower. PAP and AAP groups were found to be similar in terms of WBC, NEU, LYM, NEU%, and LYM% values. PLT and MPV values and serum lactate values did not show a significant difference between the groups. NLR was similar in the AAP and PAP groups. A significant increase in CRP versus a decrease in LCR was detected in the PAP group compared to that in the AAP group. Multivariate analysis demonstrated that only IL-6 has significant estimated accuracy rates as 80% for the control group, 78.8% for AAP, 96.9% for PAP, and 81.6% for NAP.

CONCLUSION

Rather than AAP, PAP caused significantly higher oxidative stress (increased TOS and OSI), and lower antioxidation capacity (decreased TT and NT). IL-6 levels can provide a significant stratification. Nevertheless, simply detecting WBC or CRP is not enough to distinguish the specific pathology in acute appendicitis and related conditions.

Predictors of Complicated Appendicitis with Evolution to Appendicular Peritonitis in Pediatric Patients

Background and Objecitves: Appendicitis is one of the most frequent surgical emergencies in pediatric surgery. Complicated appendicitis can evolve with appendicular peritonitis characterized by the diffusion of the pathological process to the peritoneal cavity, thus producing generalized or localized inflammation of the peritoneum. The capacity to anticipate the possibility of perforation in acute appendicitis can direct prompt management and lower morbidity. There is no specific symptom that could be used to anticipate complicated appendicitis, and diagnostic clues include a longer period of symptoms, diffuse peritoneal signs, high fever, elevated leukocytosis and CRP, hyponatremia, and high ESR. Imagistic methods, particularly US and CT, are useful but not sufficient. There are no traditional inflammation biomarkers able to predict the evolution of uncomplicated to complicated appendicitis alone, but the predictive capacity of novel biomarkers is being investigated. Materials and Methods: The present study represents a retrospective evaluation of children hospitalized between January 2021 and July 2022 in the Grigore Alexandrescu Clinical Emergency Hospital for Children with a diagnosis of acute appendicitis settled based on clinical characteristics, traditional and novel biomarkers, and ultrasonographic features. The children were subsequently grouped into two groups based on the existence of appendicular peritonitis on intraoperative inspection of the abdominal cavity. The aim of this report is to establish the predictors that may aid physicians in timely identifying pediatric patients diagnosed with acute appendicitis at risk for developing complicated appendicitis with evolution to appendicular peritonitis. Results: The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte radio (PLR) are representative severity markers in infections. This report analyzes the benefit of these markers for distinguishing uncomplicated appendicitis from complicated appendicitis in pediatric patients. Conclusions: Our study suggests that a value of neutrophil-to-lymphocyte ratio greater than 8.39 is a reliable parameter to predict the evolution to appendicular peritonitis.

Çocuklarda Akut Apandisit Tanısında Yeni Bir Belirteç Olarak Sistemik İmmün-İnflamasyon İndeksin Değerlendirilmesi

Aim: The aim of this study was to determine the usefulness of systemic immune-inflammation index (SII) in the diagnosis of acute appendicitis (AA) in children Material and Method: This study was done retrospectively, and two groups were formed as AA and control group. AA group was divided into two subgroups as nonperforated appendicitis and perforated appendicitis. The groups were compared for age, sex, WBC, neutrophil, lymphocyte and platelet count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), C-reactive protein (CRP). Results: The study included a total of 162 children. There were 81 children in the AA group and 81 in the control group. Of 81 patients included in the AA group, 31 were girls (38.3%) and 50 were boys (61.7%), and the median age of the patients was 11 (5) years. When the AA group and the control group were compared in terms of laboratory values. It was found that WBC count, neutrophil count, platelet count, NLR, PLR and SII in the AA group were significantly higher and lymphocyte count was significantly lower (p

Predicting the Severity of Acute Appendicitis in Children Using Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR)

Introduction

The ability to predict risk of perforation in acute appendicitis (AA) could direct timely management and reduce morbidity. Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) are surrogate severity markers in infections. This study investigates the use of PLR and NLR as a marker for distinguishing uncomplicated (UA) and complicated appendicitis (CA) in children.

Materials and methods

This retrospective single-center study collected data between January 1, 2014, and December 31, 2020. Children between five and 17 years of age with histologically confirmed appendicitis were included. Cut-off values for NLR and PLR were determined by employing the receiver operating characteristic (ROC) curve with sensitivity and specificity in addition to regression analysis.

Results

A total of 701 patients were included with a median age of 13 years. Out of which 52% of the cohort was female. The difference between the NLR and PLR ratios between UA and CA was significant (p=0.05, Kruskal-Wallis). For UA, the area under the ROC curve (AUC) and cut-off for NLR and PLR were 0.741, 3.80 with 95% CI of 0.701-0.781 and 0.660, 149.25 with 95% CI of 0.618-0.703, respectively. In CA, using NLR and PLR, AUC and cut-off were 0.776, 8.86 with 95%CI of 0.730-0.822 and 0.694, 193.67 with 95%CI of 0.634-0.755, respectively. All were significant with p<0.001.

Conclusions

NLR and PLR are reliable, synergistic markers predicting complicated appendicitis which can guide non-operative management in children.

Diagnostic Value of Monocyte-to-Lymphocyte Ratio Against Other Biomarkers in Children With Appendicitis

OBJECTIVES

This study aimed to investigate diagnostic value of monocyte-to-lymphocyte ratio as a novel biomarker in children with appendicitis and to compare with other biomarkers.

METHODS

A total of 683 children were included in this retrospective study. Patients were categorized as acute appendicitis (AA, n = 254), perforated appendicitis (PA, n = 82), nonspecific abdominal pain (NAP, n = 197), and control (n = 150). The groups were compared for demographics, duration of symptoms, monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), white blood cell count, neutrophil percentage (NP), C-reactive protein (CRP), mean platelet volume, and sodium level.

RESULTS

There was a significant difference between all groups for MLR, PLR, and CRP. White blood cell count, NP, and NLR were significantly increased in patients with appendicitis, but there was no significant difference in the differential diagnosis between PA and AA. Sodium levels significantly decreased in patients with appendicitis. No statistically significance was determined between all groups in term of mean platelet volume. Among the biomarkers, MLR showed the highest diagnostic value (area under the receiver operator characteristic curve = 0.798) for AA, while CRP showed excellent diagnostic value (area under the receiver operator characteristic curve = 0.897) for PA.

CONCLUSIONS

To our knowledge, this is the first study showing that MLR is a valuable parameter to differentiate patients with and without appendicitis. White blood cell, NP, and NLR are also useful parameters. On the other hand, an increased CRP level and hyponatremia are indicators of PA.

The Role of Neutrophil-Lymphocyte-Ratio (NLR) and Platelet-Lymphocyte-Ratio (PLR) as a Biomarker for Distinguishing Between Complicated and Uncomplicated Appendicitis

Introduction Acute appendicitis (AA) is one of the most common acute general surgical presentations affecting 7% of the population at some point in their lifetime. The ability to assess the risk of complicated appendicitis (CA) from uncomplicated appendicitis (UA) in acute appendicitis (AA) could reduce the associated morbidity and mortality. The value of platelet lymphocyte ratio (PLR) as an inflammatory marker increases when its fluctuations are interpreted along with other complementary hematologic indices, such as neutrophil-to-lymphocyte ratio (NLR), which provides additional information about the disease activity. Hence, we postulated that NLR and/or PLR could serve as a potential surrogate marker in assessing the severity of AA. Aim This study aims to investigate the use of PLR and/or NLR as a surrogate biomarker in differentiating uncomplicated from complicated appendicitis. Material and methods This retrospective study was conducted at Russells Hall Hospital from January 1, 2017, to December 31, 2020. Data of all patients over age 16 years that had histologically confirmed appendicitis were retrieved. NLR and PLR were calculated from the admission hemogram, and the ratios were compared between uncomplicated (UA) or complicated appendicitis (CA). Cut-off values were calculated using the summarized ROC curve; in addition, the sensitivity and specificity with 95% confidence intervals were determined using SPSS 25.0 (IBM Corp., Armonk, NY). Results A total of 799 patients were analyzed, of which 469 (58.7%) were female. The median age was 31.2 years. The difference between NLR and PLR within the two appendicitis groups was significant (P=0.05; Kruskal-Wallis). Cohen's kappa (degree of inter-rater agreement) between NLR and PLR showed a moderate agreement of 0.589 (P<0.001). We equally demonstrated an exponential relationship between PLR and NLR (R2 =0.510, P<0.05). For UA, the area under the curve (AUC) and the cut-off for NLR and PLR were 0.715, 4.75 with a confidence interval (CI) of 0.678-0.653 and 0.632, 155 with a CI of 0.591-0.672, respectively. For CA, using NLR and PLR, the AUC and cut-off were 0.727, 6.96 with a CI of 0.687-0.768 and 0.653, 180.5 with a CI of 0.602-0.703, respectively; all were significant with a P of <0.001. Conclusion NLR and PLR are a reliable, less cumbersome surrogate biomarker for assessing the severity of acute appendicitis.

Significance of laboratory parameters in diagnosing acute appendicitis during pregnancy

BACKGROUND

Acute appendicitis (AA) is the most frequently seen surgical emergency in pregnant women and the most frequently encountered cause of non-obstetric acute abdomen. Due to the physiological and anatomical changes that occur during pregnancy and the limited use of radiological methods, it is difficult to diagnose AA during pregnancy. These conditions increase the risk of morbidity and mortality; therefore, it is crucial to identify ideal laboratory markers that can be utilized to diagnose disease.

METHODS

One hundred and ten pregnancies that fulfilled the inclusion criteria for AA diagnosis were retrospectively analysed between 2010 and 2021. Markers with high diagnostic values were discussed.

RESULTS

The patients were divided into three groups as follows; Group I: negative appendectomy (n = 19); Group IIa: uncomplicated appendicitis (n = 59); Group IIb: complicated appendicitis (n = 32). There was no statistically significant difference in mean age or gestational week (P > 0.05). Group IIb had a higher rate of complications and a longer length of hospital stay (P < 0.05). There were significant differences between the groups in terms of white blood cell (WBC), neutrophil, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), C-reactive protein, lymphocyte-to- C-reactive protein ratio, total, direct, and indirect bilirubin values (P < 0.05). While platelet and lactate dehydrogenase (LDH) values did not differ substantially between groups, both were found to have a high diagnostic value.

CONCLUSION

It was concluded that WBC, neutrophil, NLR, PLR, total, direct and indirect bilirubin levels could be utilized to diagnose AA. Moreover, levels of WBC, neutrophil, NLR, platelet, PLR, LDH, total, direct and indirect bilirubin can be utilized to diagnose complicated appendicitis.

The diagnostic role of hemogram parameters in pregnant appendicitis

Background: Acute appendicitis is the most frequently encountered non-obstetric disease requiring surgical intervention during pregnancy. Early diagnosis reduces maternal and fetal morbidity / mortality rates. Aim: This study aims to investigate hemogram parameters in the diagnosis of acute appendicitis in pregnant women. Material and Methods: A retrospective case-controlled study was conducted in three groups. Thirty-nine pregnant patients with acute appendicitis (Group A), 39 fertile nonpregnant patients with acute appendicitis (Group B), and 39 healthy pregnant women (Group C) were included in the study. WBC, neutrophil count, lymphocyte count, NLR, PLR, MPV and RDW values were compared. Results: The mean NLR values in group A, group B and group C were 7.39 (1.58–46.6), 5.66 (1–20) and 4.23 (1.54–10.77) respectively, and there was a significant difference in NLR values between the groups (P= 0.002). The mean PLR values in group A, group B and group C were 159.09 (69.1–574), 134.28 (21.5-360) and 120 (68.7–334) and difference was statistically significant (P= 0.019). Cutoff points for WBC count was 14155 106/μL (51,3% sensitivity, 82,1% specificity), for neutrophil count is 10955 106/μL (53,8% sensitivity, 84,6% specificity), for NLR is 9.23 (46,2% sensitivity, 92,3% specificity) and PLR is 157,6 (51,3% sensitivity and 82,1% specificity) NLR had largest area under the curve with 0.667 NLR. Conclusion: Neutrophil count, WBC and PLR were found to be the most valuable inflammatory parameters however, RDW, Lymphocyte count, and MPV levels are not found valuable markers in terms of sensitivity and specificity in the diagnosis of acute appendicitis in pregnant patients by this study.

Are postoperative NLR and PLR associated with the magnitude of surgery-related trauma in young and middle-aged patients with bicondylar tibial plateau fractures? A retrospective study

Background

The invasiveness of different surgical procedures is variable. The purpose of this study was to investigate the value of the postoperative neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as biomarkers in assessing the magnitude of surgery-related trauma in young and middle-aged patients with bicondylar tibial plateau fractures (TPFs).

Methods

A total of 136 young and middle-aged patients with bicondylar TPFs who underwent surgical treatment between May 2016 and April 2020 were included. Details about demographic information, pre- and postoperative laboratory data, and surgical variables were obtained from the electronic database of our level I trauma center. According to the different surgery programs, all patients were divided into two groups: group 1, which represented minimally invasive reduction and internal fixation (MIRIF), and group 2, which represented open reduction and internal fixation (ORIF). Univariate and multivariate logistic regression and ROC curve analyses were used.

Results

The operative time, intraoperative tourniquet use, intraoperative blood loss, length of incision, postoperative NLR, PLR, RBC and HCRP were significantly different between the two groups (P < 0.05). In the multivariate analysis, postoperative PLR ≥ 223.9, surgical incision > 19.0 cm and operative time > 130 min were closely related to severe surgery-related trauma. The ROC curve analysis indicated that postoperative PLR could predict severe surgery-related trauma with a specificity of 76.0 % and a sensitivity of 55.7 %.

Conclusions

Postoperative PLR appears to be a useful biomarker that is closely associated with magnitude of surgery-related trauma in young and middle-aged patients with bicondylar TPFs.

Is the platelet to lymphocyte ratio a promising biomarker to distinguish acute appendicitis? Evidence from a systematic review with meta-analysis

BACKGROUND

Although several previous studies have examined the association between the platelet to lymphocyte ratio (PLR) and acute appendicitis (AA), findings have been controversial. We aimed to systematically assess the available evidence to elucidate the overall relationship between the PLR and AA.

METHODS

Pubmed and Embase databases were searched for all available published literature before August, 2019 by two independent investigators for observational studies reporting the association between the PLR and AA. Random effects models were applied for all meta-analyses. Pooled standardized mean difference (SMD) and 95% confidence interval (CI) were calculated as effect estimates.

RESULTS

Eleven articles met the inclusion criteria and included in this study. Meta-analysis showed that the level of PLR in the AA group was significantly higher than that in the control group (SMD: 1.19, 95% CI: 0.75 to 1.62, P<0.001). A series of subgroup analyses were conducted to investigate the heterogeneity, showing a significant increase in PLV levels in adults with age ≥30 years (SMD: 1.46, 95% CI: 0.89 to 2.02),compared to those in adult <30 years(SMD: 0.58, 95% CI: 0.12 to 1.04) or in children (SMD: 1.03, 95% CI: 0.51 to 1.56). Compared to non-AA controls, a significant increased PLR level was also observed in non-perforated AA (SMD: 1.23, 95% CI: 0.88 to 1.59) and in AA patients during pregnancy (SMD: 0.70, 95% CI: 0.36 to 1.04), while not in perforated AA (SMD: 2.28, 95% CI: -1.72 to 6.28).

CONCLUSIONS

A significant increase in PLR level is found in patients with AA, indicating that PLR is a promising biomarker for AA. PLR provides a convenient option for emergency department to quickly screen for clinically or radiologically confirmed AA awaiting appendectomy, especially for pregnant women suspected of having AA. More high-quality evidence is needed to further confirm the diagnostic accuracy of PLR for AA.