الفهرس 
Chronic Kidney DiseaseOnly 14 pages are availabe for public view
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Abstract
NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN (NGAL) IN RELATION TO RENAL ANEMIA OF HEMODIALYSIS PATIENTS
Anemia secondary to CKD is a complex syndrome. It is a condition frequently observed among chronic HD patients and constitutes an important cause of morbidity and mortality. These patients often have iron deficiency as a consequence of frequent blood sampling, gastrointestinal bleeding, dietary restrictions and/or decreased enteric absorption. CKD causes depression of EPO production in the kidney. Dialysate contamination may increase cytokine production (increased inflammatory stimulus) and consequently cause both depression of EPO production in the kidney and depression of EPO response in the bone marrow). The Kidney Disease Outcomes Quality Initiative (KDOQI) anemia workgroups suggest that serum ferritin and the TSAT should be considered primary tools in the assessment of iron status in nephropathic subjects. However, a large body of recently obtained evidence has led to a re-evaluation of the role of serum ferritin as a reliable index of iron storage in HD patients. This protein is an acute-phase reactant, is markedly influenced by malnutrition and has important gender differences, thus making it a less than ideal tool for identifying iron deficiency.
NGAL was initially found in activated neutrophils, however, many other cells, like kidney tubular cells, may produce NGAL in response to various insults. Recently, clinical nephrologists have discovered that NGAL can be a predictor of the progression of chronic renal diseases. NGAL can be also used as a biomarker beyond the confines of nephrology.
The aim of the present work is to evaluate circulating NGAL as a biomarker of renal anemia in chronic HD patients and its possible clinical utility as a follow up tool and a guide for management of anemia in these patients.
This study has been conducted on 40 ESRD patients on regular HD thrice weekly 4-hour sessions for more than 6 months. They were compared with 20 control individuals. The control group includes 20 healthy control subjects with Hb level ≥ 13g/dl. The patients were classified into two groups (group 1A, including 20 patients with Hb level < 11 g/dl and group 1B, including 20 patients with Hb < 13 and ≥ 11 g/dl). group 1A had been on recombinant EPO therapy for at least 6 weeks in the dose of 4000 IU twice weekly. All the individuals were subjected to full medical history and clinical examination. The lab measurements included Hb level, iron status parameters (total serum iron, serum ferritin and TSAT), CRP and serum NGAL using the ELIZA commercially available kits.
The results revealed significant difference in serum iron (p < 0.001) between the control group (135.3 ± 17.397 ug/dl) and group 1A (81.7 ± 23.49 ug/dl) and 1B (99.5 ± 36.515 ug/dl). Also, significant difference was found in serum ferritin between the control (75.3 ± 23.234 ng/ml) and group 1A (115 ± 61.529, p < 0.05) and 1B (142.2 ± 36.557 ng/ml, p < 0.001). Regarding TSAT, compared to the control group (34.25 ± 6.051 %), the difference was significant for group 1A (22.05 ± 5.907 %, p < 0.001) but insignificant for group 1B (29.4 ± 11.408 %, p > 0.05). As for CRP, the difference was significant (p < 0.01) between the control group (2.03 ± 1.006 ug/ml) and group 1A (9.458 ± 3.313 ug/ml) and 1B (7.44 ± 2.581 ug/ml). Regarding serum NGAL, the difference is significant between the control group (154.35 ± 38.348 ng/ml) and both groups 1A (222.6 ± 24.058 ng/ml, p< 0.001) and group 1B (208.15 ± 24.225 ng/ml, p< 0.01). The results revealed direct correlation (p <0.001) between CRP and ferritin (r = 0.637) and inverse correlation (p <0.001) between serum NGAL and Hb (r = – 0.631), serum iron (r = - 0.578) and TSAT % (r = – 0.446). No significant correlation was found between serum NGAL and ferritin (r = 0.244, p > 0.05).
In conclusion, the use of NGAL as a biomarker to assess renal anemia in HD patients is probably of great potential and can be used as a guide tool of iron therapy in HD patients. Further studies are needed to evaluate the real effect of chronic inflammation on circulating NGAL levels, and to make an effective cost-to-benefits analysis.