AA is part of the most common surgical emergencies 7. Diagnosis of AA largely depends on a clinical diagnosis supported by laboratory and imaging studies. AA is a well-known entity with remarkable signs and symptoms, but there is not a single parameter to diagnose it easily. Complicated appendicitis occurs once the appendix has become gangrenous and/or has perforated with numerous degrees of peritonitis. The rate of complicated appendicitis is slowly increasing and has been reported at an incidence of 12–30%8,9. A recent study suggests that perforation is not necessarily the inevitable result of appendiceal obstruction. PAA may occur more commonly in patients with altered inflammatory responses or alterations in the colonic microbiome 10. In the elderly people, the morbidity rate and mortality rate are higher in the presence of PAA 11,12. In our study, the mean age of PAA group obviously older than NPAA group. Appendectomy is the gold standard for the management of AA since the late 1800s. And subsequent technological advances and improvement in the 1990s, the LA has gradually become a mainstay of treatment for AA. Some studies indicate that LA provides advantages in terms of shorter length of stay, less postoperative pain and faster recovery time, but there is a controversy with the application of LA in PAA12. A range of novel biomarkers has been suggested during the past decade, including WBC and CRP, some studies have shown that increase in CRP and WBC are associated with the severity of AA, but these do not have external validity. In this study, we also found that NLR, PLR are reliable predictors of PAA, and NLR is significant independent predictors of diagnosis of PAA.
NLR is a novel inflammatory marker and the determination of NLR is a simple test can be easily ascertained using blood parameters involved in the complete blood count. Goodman 13first suggested that the use of NLR in the diagnosis of AA. Then a number of studies showed that NLR played a useful role in the diagnosis of AA and was different between non-complicated AA and complicated AA. Markar SR14 has demonstrated that NLR is greater diagnostic accuracy than either WBC or CRP alone in AA and is an independent predictor of positive appendicitis histology. Takayuki Shimizu15 demonstrated that a higher NLR is closely associated with severe appendicitis. In a retrospective study by Kahramanca 16 reported that an NLR cutoff value of 5.74 was found to be critical for complicated Acute Appendicitis. Furthermore, Ishizuka17 demonstrated that NLR above 8 was significant for gangrenous appendicitis. Khan A18 confirmed that an NLR > 6.36 or CRP > 28 were statistically associated with complicated acute appendicitis, and NLR had a better area under the ROC curve compared to CRP for predicting severe appendicitis. Similarly, in our study, the higher NLR was observed in the perforated appendectomy group (16.08 ± 10.48) and a cutoff value of 8.96 was found to be critical for PAA. Multiple logistic regression analysis determined that the examination of NLR is a significant screening test for the diagnosis of PAA. This conclusion supports the consequence of our present study that NLR is significant independent predictors of diagnosis of PAA.
PLR is a combination of the PLT and lymphocyte counts. The research of PLR is focused on cancers and inflammation. In a recent study, NLR, and PLR were evaluated in patients treated for familial Mediterranean fever 19; PLR was deemed increased in patients with the condition compared with the control group. In another study by Nazik 20, use of NLR, PLR, IMA, and ESR values may be helpful in the diagnosis of appendicitis. In our study, PLR was increased with inflammation and was higher in the perforated appendectomy group (237.51 ± 149.98). However, multiple logistic regression analysis determined that the examination of PLR is not an independent factor for the diagnosis of PAA.
Our study has several limitations. Firstly, this retrospective study was carried out without estimating adequate sample size, so it is difficult to fully ascertain if there are unknown confounding variables that affect NLR and PLR validity. And only patients who underwent appendectomy were included. Secondly, symptom onset to blood test time interval was not included in this study. Lastly, other clinical data such as symptoms and physical examinations were not investigated in this study. This is a study showing promising role of NLR, PLR at PAA.