Tesis

Performa Diagnostik Systemic Immune-Inflammation Index (SII) sebagai biomarker catheter related bloodstream infection (CRBSI) pada pasien hemodialisis kronik = Diagnostic Performance of the Systemic Immune-Inflammation Index (SII) as a Biomarker for catheter related bloodstream infection (CRBSI) in Chronic Hemodialysis Patients.

Latar Belakang: Catheter-Related Bloodstream Infection (CRBSI) merupakan komplikasi paling signifikan pada hemodialisis (HD), dengan insiden sekitar 3,8– 11,8 per 1000 hari kateter dan menjadi penyebab kematian tertinggi kedua setelah penyakit kardiovaskular. Diagnosis CRBSI masih bergantung pada kultur darah sebagai standar emas, namun metode ini memerlukan waktu lama dan tingkat positif yang tidak tinggi. Tujuan: Mengevaluasi performa diagnostik Systemic Immune-Inflammation Index (SII) dalam mendeteksi CRBSI pada pasien HD, dibandingkan dengan biomarker lain seperti C-reactive protein (CRP), prokalsitonin (PCT), rasio neutrofil/limfosit (RNL), dan rasio platelet/limfosit (RPL). Metode : Studi potong lintang pada 100 pasien HD dengan kateter lumen ganda yang dicurigai CRBSI. Data SII dihitung dari trombosit × neutrofil / limfosit, sedangkan nilai CRP, PCT, RNL, dan RPL diukur dari sampel darah saat evaluasi awal. Diagnosis CRBSI dikonfirmasi dengan kultur darah. Analisis kurva Receiver Operating Characteristic (ROC) dilakukan untuk tiap biomarker, menentukan area under curve (AUC), titik potong optimal, sensitivitas, spesifisitas, nilai duga positif (NDP), dan nilai duga negatif (NDN). Hasil: Dari 100 subjek, 37 (37%) terkonfirmasi CRBSI. Kelompok CRBSI menunjukkan neutrofil dan NLR yang lebih tinggi serta limfosit yang lebih rendah dibanding tidak CRBSI, sedangkan jumlah platelet serupa. Bakteri Gram-positif (terutama Staphylococcus aureus) menjadi penyebab utama (67,6%) kasus CRBSI. SII memiliki AUC 0,799 (95% IK 0,701 –0,897), titik potong 1125, sensitivitas 86,5%, spesifisitas 82,5%, NDP 74,4%, NDN 91,2%. AUC SII lebih tinggi dibanding CRP (0,573) dan RPL (0,743) dan sebanding dengan PCT (0,779) dan RNL (0,763). Empat biomarker (SII, PCT, RNL, RPL) menunjukkan kinerja diagnostik signifikan (p < 0,0001) sedangkan CRP tidak signifikan (p=0,225). Simpulan: SII menunjukkan performa diagnostik yang baik sebagai biomarker untuk deteksi CRBSI pada pasien HD kronik. SII sebanding dengan PCT dan melampaui CRP dalam akurasi diagnosis, sehingga berpotensi menjadi biomarker alternatif yang murah dan mudah diakses untuk deteksi dini CRBSI, terutama di fasilitas dengan sumber daya terbatas.
Kata kunci: SII; CRBSI; hemodialisis; biomarker; diagnosis


Background: Catheter-Related Bloodstream Infection (CRBSI) is the most significant complication in hemodialysis (HD), with an incidence ranging from 3.8– 11.8 per 1000 catheter-days, and is the second leading cause of death after cardiovascular disease. Diagnosis of CRBSI still relies on blood cultures as the gold standard; however, this method is time-consuming and has a relatively low positivity rate. Objective: To evaluate the diagnostic performance of the Systemic ImmuneInflammation Index (SII) in detecting CRBSI in chronic HD patients, compared to other biomarkers such as C-reactive protein (CRP), procalcitonin (PCT), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR). Methods: A cross-sectional study was conducted on 100 HD patients with doublelumen catheters suspected of having CRBSI. SII was calculated as platelet × neutrophil / lymphocyte, while CRP, PCT, NLR, and PLR values were obtained from blood samples taken at initial evaluation. CRBSI diagnosis was confirmed through blood culture. Receiver Operating Characteristic (ROC) curve analysis was performed for each biomarker, determining the area under the curve (AUC), optimal cut-off point, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Results: Among the 100 subjects, 37 (37%) were confirmed to have CRBSI. The CRBSI group had higher neutrophil counts and NLR, and lower lymphocyte counts compared to the non-CRBSI group, while platelet counts were similar. Grampositive bacteria—particularly Staphylococcus aureus—were the leading cause (67.6%) of CRBSI cases. SII showed an AUC of 0.799 (95% CI 0.701 –0.897), with a cut-off point of 1125, sensitivity of 86.5%, specificity of 82.5%, PPV of 74.4%, and NPV of 91.2%. The AUC of SII was higher than CRP (0.573) and PLR (0.743), and comparable to PCT (0.779) and NLR (0.763). Four biomarkers (SII, PCT, NLR, PLR) showed significant diagnostic performance (p < 0.0001), whereas CRP was not statistically significant (p=0.225). Conclusion: SII demonstrates good diagnostic performance as a biomarker for detecting CRBSI in chronic HD patients. Its accuracy is comparable to PCT and superior to CRP, indicating its potential as an alternative, affordable, and accessible biomarker for early CRBSI detection, particularly in resource-limited settings.
Keywords: SII; CRBSI; hemodialysis; biomarker; diagnosis