Acute appendicitis is a common inflammatory condition of the appendix, often caused by obstruction from fecoliths or foreign bodies, leading to bacterial overgrowth and potential necrosis.

With a lifetime risk of about 7%, it affects 100 to 150 individuals per 100,000 annually, posing a significant public health concern. The incidence is higher in developed countries, likely due to dietary factors and better healthcare access1.In India, the incidence of acute appendicitis ranges from 10 to 20 per 100,000 population annually, with variations due to socioeconomic and dietary factors, making accurate diagnosis challenging despite advances in techniques2. The Alvarado score, which includes symptoms like pain migration and elevated white blood cell count, assists in diagnosis but misdiagnosis can lead to complications such as perforation and abscess formation3. While the Alvarado score is useful, it has limitations in atypical cases, leading to increased use of imaging modalities like CT, which is highly sensitive but raises concerns about radiation exposure. Ultrasonography is non-invasive but operator-dependent, prompting renewed interest in laboratory markers such as total leukocyte count and C-reactive protein for diagnosing acute appendicitis. Leukocytosis is a typical response in acute appendicitis, with higher counts indicating more severe inflammation or complications like perforation. C-reactive protein (CRP) levels rise within hours of inflammation onset and peak within 24-48 hours, with elevated levels correlating more with complicated cases4. However, the timing of CRP measurement is crucial, as early-stage levels may not be significantly elevated5.The use of total leukocyte count (TLC) and C-reactive protein (CRP) as diagnostic markers for acute appendicitis is crucial in settings lacking advanced imaging options, aiding clinical decision-making. Combining these laboratory tests with clinical evaluations can enhance diagnostic accuracy and help determine whether patients need urgent surgery or conservative management. However, the variability in sensitivity and specificity reported in the literature highlights the need for further research on their combined effectiveness.This observational study aims to systematically evaluate the diagnostic role of total leukocyte count (TLC) and C-reactive protein (CRP) in patients with suspected acute appendicitis, assessing their accuracy individually and in combination6. Additionally, it will explore the relationship between these markers and the severity of appendicitis based on intraoperative and histopathological findings.

AIM

To evaluate the diagnostic efficacy of Total leukocyte count and C-Reactive Protein in radiologically diagnosed acute appendicitis

This observational study is designed as a hospital-based prospective investigation involving patients admitted to the Department of General Surgery at SMS Hospital, Jaipur, with symptoms suggestive of acute appendicitis. The study will commence upon approval from the review board and ethical committee, continuing until the desired number of cases is reached or until August 2024, whichever comes first. The study population will consist of patients who are radiologically diagnosed with acute appendicitis. Inclusion criteria will encompass individuals aged 15 years and older who have been confirmed as having acute appendicitis via imaging and who will undergo either open or laparoscopic appendectomy, provided they give written informed consent.

Exclusion criteria will apply to patients who are unfit for surgery, those with cases of appendicular perforation, abscess, or mass, pregnant patients diagnosed with appendicitis, and individuals with concurrent conditions that may elevate C-reactive protein (CRP) or leukocyte counts, including rheumatoid arthritis, systemic lupus erythematosus (SLE), glomerulonephritis, gout, and inflammatory bowel disease. Methodologically, clinical data and laboratory results (TLC and CRP) will be collected for all eligible participants.

STUDY PLAN

Table 1: Age distribution of study subjects according to gender

Among the 77 patients, males were maximum in all the age group. In age group of 16-20 years 15 cases belong to male while 3 cases belong to female, in age group of 21-30 years 20 cases were of male while 4 cases belong to female, in age group of 31-40 years 9 cases were of male while 8 cases were of female and lastly in age group of 41-50 years 13 cases belong to male while 5 cases were of female respectively.

Graph: Clinical symptoms and  Clinical signs of study subjects

Among the 77 patients, common clinical symptoms included migratory pain in 48 males and 15 females, anorexia in 42 males and 14 females, and fever in 36 males and 13 females, while clinical signs showed tenderness in 55 males and 20 females, and rebound tenderness in 14 males and 3 females. Additionally, leukocytosis was present in 45 males and 15 females, with elevated C-reactive protein observed in 37 males and 18 females

Table 2: USG findings ,Histopathological examination and Intraoperative findings of study subjects

Among the 77 patients, acute appendicitis was diagnosed in 66 individuals (85.71%), comprising 51 males and 19 females based on ultrasound findings, and 40 males and 16 females according to histopathological results. In contrast, 11 patients (14.28%) were found to have a normal, chronic, or healed appendix, including 9 males and 2 females

Table 3: TLC values among the patients studied

Table 4 : Diagnostic Performance of TLC

In a study of 77 patients, a total leukocyte count (TLC) cutoff of >10,000 cells/mm³ showed a sensitivity of 87.50% and specificity of 76.19% in diagnosing acute appendicitis, with an overall diagnostic accuracy of 84.42% when compared to histopathological examination (HPE) reports. These findings highlight TLC as a valuable diagnostic tool, offering clinicians critical insights for decision-making in cases of suspected acute appendicitis.

Table 5 : CRP values among the patients studied

Table 6 : Diagnostic Performance of CRP

In a study of 77 patients, a C-reactive protein (CRP) cutoff of <6 mg/dL showed a sensitivity of 91.07% and specificity of 80.95% for diagnosing acute appendicitis, with an overall diagnostic accuracy of 88.31% compared to histopathological examination (HPE) results. These findings emphasize CRP's reliability as a diagnostic tool, providing clinicians with critical information for the management of acute appendicitis.

In our study involving 77 patients, we found a mean age of 30.59 years with a standard deviation of 10.06 years. The largest age group comprised 24 individuals aged between 21 and 30 years, followed closely by 18 cases in the 16-20 years and 41-50 years age group. Conversely, the age groups of 31-40 years had 17 patients. Gender distribution in the study showed 57 male patients and 20 female patients. Similar demographic patterns were noted in a study by Srikantaiah H C et al.7 2016 where the mean age was reported as 29.84 years, and males outnumbered females, with 10 out of 40 patients being male.

All 77 patients reported pain in right iliac fossa, migratory pain was observed in 63 (81.81%) patients, a characteristic symptom where pain shifts from umbilicus to right iliac foass. Anorexia or loss of appetite, was observed in 56 patients (72.72%), highlighting its frequent occurrence. Nausea was reported by 50 patients (64.93%), while 75 patients (97.40%) experienced abdominal tenderness. Other significant symptom like vomiting present in 41 patients (53.24%). Pain localized in the right iliac fossa, a classic sign of appendicitis, was noted in all patients. Fever exceeding 38.5°C was less common but present in 49 patients (63.63%).

In terms of physical examination findings, rebound tenderness, indicative of peritoneal inflammation, was observed in 17 patients (22.07%). Elevated temperature (>38.5°C) was noted in 49 patients (63.63%), suggesting systemic inflammation. Leukocytosis, an increase in white blood cell count, was found in 60 patients (77.92%), which commonly occurs in response to infection. Guarding, a reflex involving abdominal muscle tensing, was present in 43 patients (55.84%). InLaboratory investigations further supported our clinical findings, with Total Leukocyte Count (TLC) elevated in 54 patients (70.12%), indicating inflammation. C-reactive protein (CRP), another inflammation marker, was elevated in 55 patients (71.42%), underscoring its diagnostic value in acute appendicitis response to a variety of inflammatory conditions and tissue necrosis.Talabai et al.8 2021 shows the specificity of 89.5%, however, the sensitivity was low (51.9%) suggesting that WBC count would have missed a substantial number of patients with acute appendicitis. There is no general consensus in the medical literature regarding which WBC cutoff values are optimal for maximizing predictive values, the cut-off established in the current study is comparable with that obtained by However, John et al.9 2011 are of the opinion that CRP is the earliest inflammatory marker whose concentration has been found to rise on repeated testing whereas leucocyte counts have been found to decrease. In spite of this contrasting observations, one of the major advantages of CRP is its ease of measurement and cost-effectiveness for rural communities where CT, MRI, and laparoscopy are not available.

Our study involving 77 patients shows that 55 (71.42%) had elevated C-reactive protein (CRP) levels, while 22 (28.57%) exhibited normal or low CRP levels. The CRP cutoff of <6 mg/dL demonstrated robust diagnostic performance: it showed a sensitivity of 91.07%, accurately identifying patients with acute appendicitis among those who had the condition. The test also demonstrated a specificity of 80.95%, effectively excluding acute appendicitis in patients without the condition. Furthermore, the high positive predictive value (PPV) of 92.73% indicated that a positive CRP result reliably confirmed acute appendicitis, while the negative predictive value (NPV) of 77.27% highlighted the test's ability to correctly identify cases where acute appendicitis was absent. Overall, the CRP test achieved an impressive diagnostic accuracy of 88.31% in this study, underscoring its effectiveness as a diagnostic tool for acute appendicitis when compared to histopathological examination. A recent study Monsalve S et al. 10 2021 reported that the sensitivity and specificity of CRP in identifying complicated appendix were 74% and 74%, respectively, at this cut-off of 361.9 umol/L. Other studies Shogilev et al 11 reported an association between disease severity and CRP level. This implies that CRP appears to be helpful in identifying patients with complicated appendicitis but its predictive values in appendicitis are limited as a sole diagnostic investigation as alluded to by some researchers 12,13.

Based on the diagnostic efficacy of C-Reactive Protein (CRP) at 88.31% and Total Leukocyte Count (TLC) at 84.42% in radiologically diagnosed acute appendicitis, it is advisable to recommend TLC and CRP blood tests for patients clinically suspected to have acute appendicitis with right iliac fossa pain. These tests can significantly reduce the rate of negative appendectomy, where patients undergo unnecessary surgical removal of the appendix when it is found to be normal upon histopathological examination.

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