The effect of RDW/PLT ratio at the time of diagnosis on disease severity in patients hospitalized for acute pancreatitis

Objective: Acute pancreatitis (AP) is an inflammatory condition characterized by abdominal pain and the elevation of pancreatic enzymes in the blood. It is one of the leading causes of hospitalization for gastrointestinal disorders. Gallstones and chronic alcohol use are the primary causes of AP etiology, accounting for approximately two-thirds of cases. The annual incidence of AP is 4.9-35/100,000. The incidence of AP is increasing worldwide due to the rise in obesity and gallstones. AP is a disease that can vary in severity and is mostly mild or moderate, with patients recovering completely. In AP, death often occurs during the first two weeks due to systemic inflammatory response syndrome and organ failure, while after two weeks it is caused by sepsis and its complications. One of the indices used to determine the severity of AP is the Bedside Index of Severity in Acute Pancreatitis (BISAP) scoring system. The BISAP score is based on a study conducted between 2000 and 2001 involving 17,922 cases of AP. Between 2004 and 2005, this study was validated in 18,256 cases. In the BISAP scoring system, a BUN level >25 mg/dL within the first 24 hours, impaired mental status, SIRS, age over 60, or the presence of pleural effusion are each scored as one point. The mortality rate was found to be below 1.4% in patients with a score of zero, while the mortality rate was observed to be 22% in patients with a score of 5. Red blood cell distribution width (RDW) is a measure of variation in the size of red blood cells. Although the cause remains unknown, an increase in RDW is associated with an increased mortality rate in patients with many disease groups. Platelets are fragments of megakaryocyte cytoplasm. They play an important role in cellular hemostasis. Conditions such as acute sepsis, tissue necrosis, vascular wall disorders, and chronic inflammatory diseases lead to increased platelet consumption. The RDW/PLT ratio stands out as an easily accessible and low-cost hematological parameter that reflects the severity of inflammation. An increased RDW value reflects cellular stress and inflammation, while a decreased platelet count reflects the severity of the disease. Studies in the literature show that it can be used as a prognostic predictor in AP, sepsis, liver diseases, heart failure, and some malignancies. In our study, we aimed to reveal the relationship between the RDW/PLT ratio and the severity of AP in patients hospitalized due to AP. Materials and Methods: In this retrospective study, the records of 229 patients aged 18 years and older who were admitted to the Internal Medicine Clinic of Afyonkarahisar Health Sciences University Hospital with an AP diagnosis between January 2020 and July 2024 were reviewed, and those who met the exclusion criteria were excluded. Patients were divided into two groups based on their length of hospital stay: those with a stay of 7 days or less were classified as early discharge, and those with a stay of 8 days or more were classified as late discharge. RDW/PLT values at the time of AP diagnosis were compared with BISAP index scores and hospital stay lengths. Statistical analyses were performed using the SPSS version 25.0 program. Findings: Of the 105 AP patients included in our study, 36 (34.3%) were female and 69 (65.7%) were male. Of these patients, 64 (60.95%) were under 60 years of age and 41 (39.04%) were 60 years of age and older. The most common chronic disease among the patients was hypertension, seen in 34 (32.4%) patients. The second most common was diabetes mellitus in 32 (30.5%) patients, and the third was hyperlipidemia in 22 (21%) patients. The mean age was 53.1±20.12, and the mean length of stay was 6.4±2.7 days. When patients' BISAP scores and length of stay were statistically analyzed, a positive statistically significant (p<0.05) relationship was found between them. When statistically comparing the RDW/PLT values of patients with BISAP scores <3 and 3 and above, it was observed that the RDW/PLT value was significantly (p<0.05) higher in patients with BISAP scores of 3 and above compared to patients with scores <3. No statistically significant difference was observed in the comparison of patients' RDW/PLT values according to length of stay and CRP, BUN, creatinine, hematocrit, triglyceride, HDL, and LDL cholesterol levels. (p>0.05). There was a statistically significant positive relationship (p<0.05) between RDW levels and length of stay, between age and length of stay, BUN levels and length of stay, creatinine levels and length of stay, a statistically significant negative relationship was found (p<0.05), between high density lipoprotein cholesterol (HDL-C) and length of stay, and between low density lipoprotein cholesterol (LDL-C) and length of stay. Results: The data obtained from our study indicate that the RDW/PLT ratio during hospitalization and parameters such as RDW, creatinine, BUN, HDL-C, LDL-C, and age may be associated with clinical severity. However, prospective, multicenter studies with larger sample sizes are needed to make more accurate predictions in the assessment of AP prognosis.