| Abstract|| |
Background: Accurately differentiating simple and complicated acute appendicitis (CAA) in children preoperatively can be challenging. The aim of this study is to evaluate the ability of the neutrophil-to-lymphocyte ratio (NLR), total leukocyte count (TLC), percentage lymphocyte, and percentage neutrophil counts to predict the type of appendicitis a patient has preoperatively and to determine the better indicator among these. Materials and Methods: Record of 233 patients under 18 years of age who underwent appendectomy from 2005 to 2014 was evaluated. Based on perioperative findings of the surgeon, the patients were grouped under categories simple acute appendicitis (SAA) and CAA. Information such as age, gender, and laboratory investigations of the patients were recorded and analyzed. Results: SAA included 185 patients and CAA included 48 patients. An NLR >4.8, TLC >13,500 cells/mm3, percentage lymphocyte count <14.8%, and percentage neutrophil count >75% were found to be associated with complicated appendicitis. The highest sensitivity and specificity among these findings were found with the percentage lymphocyte count, which were 70.8% and 63.8%, respectively. Conclusion: The preoperative percentage lymphocyte count serves as a better indicator than TLC, NLR, and percentage lymphocyte count and is a useful parameter in differentiating simple and complicated appendicitis and can be used as a valuable adjunct to the surgeon's clinical evaluation.
Keywords: Appendicitis, lymphocyte, neutrophil
|How to cite this article:|
Virmani S, Prabhu PS, Sundeep P T, Kumar V. Role of laboratory markers in predicting severity of acute appendicitis. Afr J Paediatr Surg 2018;15:1-4
|How to cite this URL:|
Virmani S, Prabhu PS, Sundeep P T, Kumar V. Role of laboratory markers in predicting severity of acute appendicitis. Afr J Paediatr Surg [serial online] 2018 [cited 2019 Sep 16];15:1-4. Available from: http://www.afrjpaedsurg.org/text.asp?2018/15/1/1/253259
| Introduction|| |
Acute appendicitis is one of the most common causes of abdominal pain and is the most frequent cause of emergency abdominal surgery in children. It is common between the ages of 7–15 years but can occur at any age. The diagnosis of acute appendicitis is mainly based on clinical assessment, and this involves the use of well-known symptoms and signs such as right lower quadrant abdominal pain, fever, vomiting, and McBurney's point tenderness. The laboratory predictors are not constant and their accuracy is questionable, especially the leukocyte count and C-reactive protein (CRP), which are sensitive tests but are not specific for acute appendicitis. However, a combination of both tests in the presence of symptoms and signs seems to increase their specificity significantly, but the diagnosis of acute appendicitis is unlikely when both investigations are normal. It has, however, been reported that the neutrophil-to-lymphocyte ratio (NLR) is a good predictor in the preoperative diagnosis of acute appendicitis.,,
In this context, other inflammatory markers such as interleukins, leukocyte elastase activity, phospholipase A2, serum amyloid A, and D-lactate have been studied, but most of these investigations are available only in tertiary centers and laboratories in third world countries. We aimed to study the usefulness of universally available investigations total leukocyte count (TLC), percentage neutrophil count, percentage lymphocyte counts, and NLR as obtained from doing differential leukocyte count (DLC) in the diagnosis of acute appendicitis in children. We also tried to determine the role of NLR in positively diagnosing types of appendicitis (simple and complicated).
| Materials And Methods|| |
We retrospectively reviewed the medical records of 233 patients below the age of 18 years who underwent appendectomy for appendicitis between the years 2005 and 2014 at the department of paediatric surgery which was proved peroperatively and histopathologically. The clinical diagnosis of appendicitis was established preoperatively by means of clinical history (abdominal pain, vomiting, and fever), physical examination (tenderness at McBurney's point), traditional laboratory tests (hemoglobin, TLC, and DLC), and in some patients, by imaging studies such as ultrasonography. Laboratory tests were performed on blood samples obtained on the day of admission to the hospital. Data collected from the medical records of these patients included the age, gender, the time taken from the onset of the first symptom to the day of presentation (duration of symptoms), clinical symptoms and signs, the TLC, DLC, operative findings, and the histopathology reports.
The data of a total of 233 patients were analyzed. Pathology reports were used to confirm the presence of an inflamed appendix. According to the intraoperative findings, the patients were grouped into two categories, simple acute appendicitis (SAA), and complicated acute appendicitis (CAA). Complicated appendicitis was defined as the presence of intra-abdominal abscess, perforated appendix, phlegmon, gangrenous appendix, and appendicular mass.
The data analysis was performed using the Statistical Package for the Social Sciences for Windows, version 15.0, published by SPSS Inc., Chicago, USA. The cutoff values of parameters for discrimination of the groups were determined using the receiver operator characteristic (ROC) analysis. At each value, the sensitivity and specificity for each outcome under study were plotted, thus generating an ROC curve. Area under the ROC curve was used to determine the predictive (diagnostic) ability of TLC, NLR, and percentage neutrophil and lymphocyte counts for predicting simple and complicated cases of acute appendicitis. An optimum cutoff value was selected which gave high sensitivity as well as specificity for CAA.
| Results|| |
Of the 233 patients studied, there were 185 patients in group SAA and 48 patients in group CAA. There was no significant difference in the mean age of the two groups (11.83 years of age for SAA and 10.42 years of age for CAA). The percentage of males in group SAA was 78.9% while the percentage of males in group CAA was 79.7%.
The TLC, NLR, and percentage lymphocyte counts were compared in [Table 1]. The TLC cutoff value was 13,500 cells/mm3. Values greater than this cutoff value were considered to be complicated and values lower than the cutoff value were considered to be simple appendicitis. The sensitivity was 68.8%, specificity was 60.5%, positive predictive value (PPV) was 31.1%, and negative predictive value (NPV) was 88.1% [Figure 1].
|Table 1: Comparison of total leukocyte count, neutrophil-to-lymphocyte ratio, and percentage lymphocyte count|
Click here to view
|Figure 1: Receiver operator characteristic curve for total leukocyte count|
Click here to view
The NLR cutoff value was 4.8; values greater than this were considered to be complicated and values lesser than this were considered to be simple. This resulted in sensitivity of 66.7%, specificity of 60.5%, PPV of 30.4%, and NPV of 87.5% [Figure 2].
|Figure 2: Receiver operator characteristic curve for neutrophil-to-lymphocyte ratio|
Click here to view
The cutoff value for neutrophil count was 75%. Values greater than this cutoff value were considered to be complicated and values lesser than this were considered to be simple. The sensitivity was 58% and specificity was 60% [Figure 3].
|Figure 3: Receiver operator characteristic curve for percentage neutrophil count|
Click here to view
The cutoff value for lymphocyte count was 14.8%. Values greater than this cutoff value were considered to be simple and values lesser than this were considered to be complicated. The sensitivity was 70.8%, specificity was 63.8%, PPV was 33.6%, and NPV was 89.3% [Figure 4].
|Figure 4: Receiver operator characteristic curve for percentage lymphocyte count|
Click here to view
The duration of symptoms which was the period between the appearance of the first symptom and presentation at the hospital was noted.
For all cases with duration of symptoms within the first 24 h before presentation, 96.5% were in group SAA. For all cases with duration of symptoms between 24 h and 48 h before presentation, 79.6% of the cases were in group SAA. For all cases with symptoms having started more than 48 h before presentation, 71.7% were in group SAA [Table 2].
|Table 2: Comparison of duration of symptoms with severity of appendicitis|
Click here to view
| Discussion|| |
Most studies done in the past have successfully proved that the NLR ratio has better accuracy than white blood cell counts and CRPs. This study shows that NLR with a cutoff value of 4.8 can significantly help in differentiating a simple case of acute appendicitis from a complicated one. This ratio is similar to the ratio derived in previous reports such as in the reports by Kahramanca et al., Goodman et al., and Yazici et al., but quite low compared to the value reported by Ishizuka et al. Kahramanca et al. reported a sensitivity and specificity of 70.8% and 48.5%, respectively, at NLR of 5.74, while Ishizuka et al. found a sensitivity and specificity of 73% and 39%, respectively, at NLR of 8. The sensitivity of NLR in our study is slightly lower, whereas the specificity is much higher as compared to these studies.
Studies have shown that WBC counts are always elevated in complicated appendicitis such as phlegmon and perforation., Our study, however, shows that at a TLC cutoff value of 14,000 cells/mm3, the specificity remains the same, whereas the sensitivity is slightly higher, when compared to the NLR ratio. Thus, TLC and NLR seem to be equally dependable indicators of simple or complicated appendicitis. Al-Gaithy et al. reported a cutoff limit of TLC 11,100 cells/mm3 and Hotic et al. reported a neutrophil cutoff count of 15,760 cells/mm3 to differentiate complicated appendicitis from simple appendicitis.
This study also shows the relationship between the duration of symptoms and the likelihood of a case being simple or complicated. It was observed that cases with short duration of symptoms were much more likely to be SAA, whereas complicated appendicitis was more likely to have longer duration of symptoms. Bickel et al. reported a duration longer than 36 h between onset of pain and surgery to carry higher risk of perforation, whereas Moon et al. found no correlation between the two.
We have found that the percentage lymphocyte count serves as a much better indicator in the diagnosis of complicated appendicitis than TLC and NLR ratio, due to its high level of sensitivity and specificity. Although Kahramanca et al. suggested that the lymphocyte count decreases in complicated appendicitis and has relevance in diagnosis, they have not found high values of sensitivity and specificity.
| Conclusion|| |
Although NLR and TLC are both reliable parameters that can be considered in distinguishing complicated appendicitis from SAA, the percentage lymphocyte count has proven to be a much better indicator than NLR and TLC. However, the values are not high enough to supersede the surgeon's clinical evaluation and imaging studies but may help as an added indicator for the surgeon to expect complications and determine better outcome for the child.
Financial support and sponsorship
This study was financially supported by the Department of Statistics, Medical Records Department, KMC, Manipal.
Conflicts of interest
There are no conflicts of interest.
| References|| |
Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med 1986;15:557-64.
Mekhail P, Naguib N, Yanni F, Izzidien A. Appendicitis in paediatric age group: Correlation between preoperative inflammatory markers and postoperative histological diagnosis. Afr J Paediatr Surg 2011;8:309-12.
] [Full text]
Stefanutti G, Ghirardo V, Gamba P. Inflammatory markers for acute appendicitis in children: Are they helpful? J Pediatr Surg 2007;42:773-6.
Goodman DA, Goodman CB, Monk JS. Use of the neutrophil: Lymphocyte ratio in the diagnosis of appendicitis. Am Surg 1995;61:257-9.
Markar SR, Karthikesalingam A, Falzon A, Kan Y. The diagnostic value of neutrophil: Lymphocyte ratio in adults with suspected acute appendicitis. Acta Chir Belg 2010;110:543-7.
Yazici M, Ozkisacik S, Oztan MO, Gürsoy H. Neutrophil/lymphocyte ratio in the diagnosis of childhood appendicitis. Turk J Pediatr 2010;52:400-3.
Yang HR, Wang YC, Chung PK, Chen WK, Jeng LB, Chen RJ, et al
. Laboratory tests in patients with acute appendicitis. ANZ J Surg 2006;76:71-4.
Eriksson S, Granström L, Olander B, Pira U. Leucocyte elastase as a marker in the diagnosis of acute appendicitis. Eur J Surg 1995;161:901-5.
Grönroos JM, Forsström JJ, Irjala K, Nevalainen TJ. Phospholipase A2, C-reactive protein, and white blood cell count in the diagnosis of acute appendicitis. Clin Chem 1994;40:1757-60.
Lycopoulou L, Mamoulakis C, Hantzi E, Demetriadis D, Antypas S, Giannaki M, et al
. Serum amyloid A protein levels as a possible aid in the diagnosis of acute appendicitis in children. Clin Chem Lab Med 2005;43:49-53.
Caǧlayan F, Cakmak M, Caǧlayan O, Cavuşoglu T. Plasma D-lactate levels in diagnosis of appendicitis. J Invest Surg 2003;16:233-7.
Kahramanca S, Ozgehan G, Seker D, Gökce EI, Seker G, Tunç G, et al
. Neutrophil-to-lymphocyte ratio as a predictor of acute appendicitis. Ulus Travma Acil Cerrahi Derg 2014;20:19-22.
Ishizuka M, Shimizu T, Kubota K. Neutrophil-to-lymphocyte ratio has a close association with gangrenous appendicitis in patients undergoing appendectomy. Int Surg 2012;97:299-304.
Andersson RE. Meta-analysis of the clinical and laboratory diagnosis of appendicitis. Br J Surg 2004;91:28-37.
Guraya SY, Al-Tuwaijri TA, Khairy GA, Murshid KR. Validity of leukocyte count to predict the severity of acute appendicitis. Saudi Med J 2005;26:1945-7.
Al-Gaithy ZK. Clinical value of total white blood cells and neutrophil counts in patients with suspected appendicitis: Retrospective study. World J Emerg Surg 2012;7:32.
Hotic N, Hasukic S, Cickusic E, Rifatbegovic Z, Husaric E. Diagnostic value of serum inflammatory markers (Leucocyte count, C reactive protein and neutrophil count) for detection of acute appendicitis in children. Acta Med Saliniana 2012;41:44-9. [doi: 10.5457/ams. 280.12].
Bickell NA, Aufses AH Jr., Rojas M, Bodian C. How time affects the risk of rupture in appendicitis. J Am Coll Surg 2006;202:401-6.
Moon HM, Park BS, Moon DJ. Diagnostic value of C-reactive protein in complicated appendicitis. J Korean Soc Coloproctol 2011;27:122-6.
Dr. Padubidri Santosh Prabhu
Department of Paediatric Surgery, Kasturba Medical College, Manipal University, Manipal - 576 104, Karnataka
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2]