Yoğun Bakım Hastalarında 30 Günlük Mortalite İçin Serum Kalprotektin ve Keşifsel Bir Bileşik İndeks: Prospektif Gözlemsel Çalışma

Öz

Amaç: Birincil amaç, yoğun bakıma kabulde serum kalprotektinin 30 günlük tüm nedenlere bağlı mortaliteyi ayırt etme performansını değerlendirmektir. İkincil keşifsel amaç, organ yetmezliği skoru, kalprotektin ve laktatın çarpımıyla oluşturulan bileşik indeksi incelemektir. Gereç ve Yöntem: Bu tek merkezli prospektif çalışmaya Ocak 2024–Mart 2025 arasında 76 erişkin hasta alındı. İlk 24 saatte alınan serumda kalprotektin enzime bağlı immünosorbent analizle ölçüldü. Ayırt edicilik, alıcı işletim karakteristiği eğrisi altında kalan alan ve %95 güven aralıklarıyla değerlendirildi. İndeks tüm hastalarda bileşenlerden yeniden hesaplandı. Beş ikili eğri karşılaştırmasına Holm düzeltmesi uygulandı; 5.000 tabakalı bootstrap tekrarıyla belirsizlik ve eşik kararlılığı incelendi. Bulgular: Sekiz hasta (%10,5) öldü. Kalprotektin medyanı ölenlerde 16,06, yaşayanlarda 8,20 µg/mL idi (p=0,005). Eğri altında kalan alan kalprotektin için 0,804 (%95 güven aralığı: 0,665–0,944), laktat için 0,903 ve düzeltilmiş indeks için 0,941 (%95 güven aralığı: 0,860–1,000) bulundu. Çoklu karşılaştırma düzeltmesinden sonra indeksin hiçbir tekil parametreye üstünlüğü gösterilemedi. İndeksin yeniden örneklemeye alınmayan hastalardaki ortalama duyarlılığı %73,7, özgüllüğü %87,2 idi. Sonuç: Serum kalprotektin bu küçük kohortta 30 günlük mortaliteyle ilişkiliydi. Bileşik indeksin yüksek gözlenen ayırt ediciliği klinik üstünlük veya doğrulanmış kullanım eşiği göstermemektedir. Az olay sayısı ve eşik kararsızlığı nedeniyle sonuçlar hipotez oluşturucudur; bağımsız doğrulama gereklidir.

Anahtar Kelimeler

• Biyobelirteçler
• Kalprotektin
• Mortalite
• Yoğun bakım üniteleri

Etik Beyan

Çalışma protokolü, Hitit Üniversitesi Klinik Araştırma Etik Kurulu tarafından onaylanmıştır (Onay No: 2023-76; Tarih: 21.08.2023). Tüm katılımcılardan veya yasal temsilcilerinden kayıt öncesinde yazılı bilgilendirilmiş onam alınmıştır. Tüm işlemler, Helsinki Bildirgesi'nin (2013 revizyonu) etik ilkelerine uygun olarak yürütülmüştür.

Serum Calprotectin and an Exploratory Composite Index for 30-Day Mortality in Intensive Care Patients: A Prospective Observational Study

Öz

Objective: The primary objective was to assess the discriminatory performance of admission serum calprotectin for 30-day all-cause mortality. The secondary exploratory objective was to evaluate a composite index calculated by multiplying the Sequential Organ Failure Assessment score, calprotectin, and lactate. Materials and Methods: This single-center prospective study included 76 adults admitted to intensive care between January 2024 and March 2025. Serum calprotectin was measured by enzyme-linked immunosorbent assay within 24 hours of admission. Areas under the receiver operating characteristic curves and 95% confidence intervals were used to quantify discrimination. The index was recomputed from its components for every patient. Five pairwise curve comparisons underwent Holm correction. Uncertainty and threshold stability were examined using 5,000 stratified bootstrap resamples. Results: Eight patients (10.5%) died. Median calprotectin was 16.06 µg/mL in non-survivors versus 8.20 µg/mL in survivors (p=0.005). The area under the curve was 0.804 (95% confidence interval: 0.665–0.944) for calprotectin, 0.903 for lactate, and 0.941 (95% confidence interval: 0.860–1.000) for the corrected index. No superiority of the index over any individual parameter was demonstrated after multiplicity correction. Mean out-of-bag sensitivity and specificity of the index were 73.7% and 87.2%, respectively. Conclusion: Serum calprotectin was associated with 30-day mortality in this small cohort. The composite index’s high apparent discrimination does not establish clinical superiority or a validated clinical threshold. Given the small number of events and the unstable thresholds, these findings are hypothesis-generating; independent validation is required.

Anahtar Kelimeler

• Biomarkers
• Calprotectin
• İntensive care units
• Mortality

Etik Beyan

The study protocol was approved by the Hitit University Clinical Research Ethics Committee (Approval No: 2023-76; Date: 21.08.2023). Written informed consent was obtained from all participants or their legal representatives prior to enrollment. All procedures were conducted in accordance with the ethical principles of the Declaration of Helsinki (2013 revision).

Kaynakça

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