Using urinary neutrophile gelatinase-associated lipocalin for prognosticate renal dysfunction in children with familial Mediterranean fever the study design: a pilot study

Abstract

Background The most important finding that affects the prognosis in Familial Mediterranean Fever is renal amyloidosis. The aim of the present study was to analyze neutrophil gelatinase-associated lipocalin levels in the urine, and to investigate whether it may be used as an early marker for renal involvement. Methods Forty attack-free children followed by diagnosis of Familial Mediterranean Fever with age range of 5 and 18 years, and 38 healthy children with similar ages and genders were enrolled into the study. Hemogram, sedimentation, C-reactive protein, urine analysis, creatinine in the spot urine, microalbumin and urinary neutrophil gelatinase-associated lipocalin levels were analyzed and evaluated statistically in the patients and controls. Results There was not any statistically significant difference between the patient and control groups for age, gender, height and body weight. Although there was not any clinical sign of attack in the patient group, sedimentation, C-reactive protein and fibrinogen levels were significantly higher than the control group (p = 0.002, p = 0.023, and p = 0.006, respectively). Similarly, urinary neutrophil gelatinase-associated lipocalin level and urinary creatinine ratio were significantly higher in the patient group (p = 0.0001, p = 0.011, respectively). We found a positive correlation between uNGAL level and uNGAL/uCr ratio and number of attacks per year in FMF patients (r = 0.743, p = 0.001 and r = 0.516, p = 0.001; respectively). Conclusions Detection of significantly higher levels of urinary neutrophil gelatinase-associated lipocalin level and urinary neutrophil gelatinase-associated lipocalin level to creatinine ratio were suggested as urinary neutrophil gelatinase-associated lipocalin level as a non-invasive marker for renal involvement better than microalbumin.

The spectrum of urological disease in familial Mediterranean fever: amyloidosis and beyond

“…MA/creatinine ratio is more sensitive than the rough estimation of urinary MA. Although mutations of MEFV gene, particularly homozygous M694V mutation, are associated with higher risk of amyloidosis, 23 in a case series, the different mutations were not correlated with urinary MA and urinary MA/creatinine ratio. 42 2) Serum amyloid A levels are significantly correlated to the risk of mortality from amyloidosis.…”

“…22 Proteinuria and eventual uremia are the main presenting symptoms of secondary amyloidosis. 23 Patients may initially present with amyloidosis (2%) rather than typical febrile attacks of FMF. 11 Risk factors implicated in the development of amyloidosis include M694V mutation, male gender, age of disease onset, and frequency of attacks 24,25 plus country of origin.…”

“…1) Urinary microalbumin (MA) was widely accepted as the principle early predictor of FMFrelated amyloidosis. 23 It is considered a marker of subclinical inflammation. MA/creatinine ratio is more sensitive than the rough estimation of urinary MA.…”

“…Urinary NGAL/creatinine ratio was thought to be a more sensitive marker for FMF-related amyloidosis compared to urinary MA/creatinine ratio. 23 5) Urinary glycosaminoglycans (GAGs), mucopolysaccharides found in the form of urinary unbound polysaccharides, are components of the glomerular basement membrane. They participate in the building structure of deposited renal amyloid, get consumed and their urinary levels become less detectable.…”

Amyloidosis and Glomerular Diseases in Familial Mediterranean Fever

“…Oksay and colleagues evaluated serum and urinary markers in a cohort of 45 attack-free FMF children and 38 healthy controls of comparable ages, demonstrating significantly higher urinary NGAL ( p = 0.0001) and urinary NGAL/urinary creatinine ratio (uNGAL/uCr) ( p = 0.011) in the patients’ group than in controls. Moreover, both uNGAL level and uNGAL/uCr ratio were positively correlated to the number of attacks/year in FMF children ( r = 0.743, p = 0.001 and r = 0.516, p = 0.001; respectively) [ 59 ].…”