ANALISIS KORELASI DAN PENETAPAN NILAI CUT-OFF RET-HE DENGAN REFERENSI CHR UNTUK DIAGNOSIS DEFISIENSI BESI PADA PASIEN HEMODIALISIS RUTIN

Latar belakang: Anemia defisiensi besi salah satu komplikasi yang sering ditemukan pada pasien penyakit ginjal kronik yang menjalani hemodialisis (PGK- HD). Pengukuran secara langsung konsentrasi hemoglobin rata-rata pada prekursor sel darah merah (retikulosit) dapat mengidentifikasi defisiensi besi namun ketersediaan alat hematologik untuk pengukuran konsentrasi hemoglobin retikulosit terbatas. Parameter reticulocyte hemoglobin content (CHr) dengan metode electro-optical flowcytometry dan reticulocyte hemoglobin equivalent (Ret-He) metode fluorescent flowcytometry dapat mengukur konsentrasi hemoglobin retikulosit. Pemeriksaan Ret-He berpotensi untuk dapat digunakan sebagai pemeriksaan rutin defisiensi besi.Tujuan : Mengetahui korelasi Ret-He dan CHr, serta nilai cut-off Ret-He untuk diagnosis defisiensi besi sesuai pengukuran CHr pada cut-off <29 pgMetode : Penelitian observasional untuk melihat korelasi Ret-He dan CHr serta penetapan cut-off menggunakan kurva ROC.Hasil : Subjek penelitian sejumlah 125 pasien PGK-HD dengan rerata usia 50,62 tahun, laki-laki 75(60%), dengan penyakit etiologi terbanyak adalah hipertensi59(47%), disusul diabetes melitus 39(31%). Sebanyak 92,8% pasien telah menjalani HD >6 bulan, dengan rerata Hb 9,34 g/dL. Korelasi Ret-He dan CHr sangat kuat ( r= 0,8221, p<0,001). Luas area under curve Ret-He adalah 0,889 untuk diagnosis defisiensi besi sesuai pemeriksaan CHr pada cut-off <29 pg. Pada cut-off <29 pg Ret-He menunjukkan sensitivitas (Sn), spesifisitas (Sp), nilai ramal positif (NRP), nilai ramal negatif (NRN), positive likelihood ratio (+LR), negative likelihood ratio (-LR) berturut-turut 48,84%, 97,56%, 91,3%, 78,4%, 20,02 dan0,52, dan pada cut-off <30,9 pg Ret-He menunjukkan Sn, Sp, NRP, NRN, +LR, - LR berturut-turut 86,05%, 91,46%, 84,1%, 92,6%, 10,08 dan 0,15Simpulan : Ret-He berkorelasi kuat dengan CHr. Pada cut-off 90% sesuai dengan CHr <29 pg, cut-off terbaik adalah<30,9 pg dengan Sn 86,05%, Sp 91,46%.Background: Iron deficiency anemia is one of the most common complication in patients with chronic kidney disease undergoing hemodialysis (CKD-HD). Direct measurement of mean hemoglobin concentration in red blood cell precursors (reticulocytes) may identify iron deficiency but the availability of hematologic instrument for reticulocyte hemoglobin concentration measurement is limited. Parameters of reticulocyte hemoglobin content (CHr) by electro-optical flowcytometry and reticulocyte hemoglobin equivalent (Ret-He) by fluorescent flowcytometry method may measure reticulocyte hemoglobin concentration. Ret- He examination has the potential to be used as a routine measurement for iron deficiency.Objective: To assess the correlation between RET-He and CHr, as well as identify the optimal cut-off value of RET-He for iron deficiency diagnosis that correspends to CHr <=29 pgMethod: An observational study to assess the correlation between Ret-He andCHr and the cut-off determination using the ROC curve.Results: A total of 125 CKD-HD patients with mean age of 50.62 years, 75 men (60%), with the most common etiology being hypertension in 59 (47%) patients, followed by diabetes mellitus in 39 (31%) patients. As many as 92.8% of patients had undergone HD 6 months, with mean Hb of 9.34 g/dL. The Ret-He and CHr had very strong correlation (r = 0.8221, p <0.001). The area under curve for Ret- He was 0.889 for iron deficiency diagnosis according to the CHr cut-off <=29 pg. At cut-off <=29 pg, Ret-He showed sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (+LR), negative likelihood ratio (-LR) 48, 84%, 97.56%, 91.3%, 78.4%, 20.02 and 0.52, respectively, and at the cut-off <= 30.9 pg Ret-He showed Sn, Sp, PPV, NPV, +LR, -LR respectively 86.05%, 91.46%, 84.1%, 92.6%, 10.08 and 0.15, respectivelyConclusion: Ret-He had strong correlation with CHr. At cut-off <= 29 pg, Ret-He had a specificity 90% according to CHr <= 29 pg, the optimal cut-off was <= 30.9 pg with Sn 86.05%, Sp 91.46%.