Glomerular Filtration Rate in Examined Population of Bosnian Posavina - Region of Balkan Endemic Nephropathy

Abstract

Balkan endemic nephropathy (BEN) is chronic tubulointersticial nephritis of unknown aetiology characterized by an insidious onset and gradual progression to end stage renal disease (ESRD). Endemic regions of Bosnia and Herzegovina are Posavina and Semberija, sited at basin of Sava River. In BEN, just like in other chronic renal diseases (CKD), glomerular filtration rate (GFR), is assumed a marker of overall renal function. The aim of this study was to compare GFR in examinees of endemic and non-endemic region for BEN, and between examinees with and without risk factors for BEN within endemic region. Study included 603 inhabitants of Bosnian Posavina, out of whom 386 (65%) from endemic (Domaljevac) and 217 (36%) from non-endemic (Svilaj) village, and it was performed in two phases. The first phase encompassed obtaining anamnestic data (demographic, personal and family history), measurement of arterial blood pressure, and urine dipstick testing (specific gravity, pH, proteins, leukocytes, glucose, ketones, and microalbuminuria). In the second phase, besides repeated urine dipstick test, laboratory blood testing and abdominal ultrasound, with special attention to urinary tract, was also performed. We have compared GFR between examinees of endemic and non-endemic regions for BEN, and between examinees with and without family burden for BEN within endemic region, using MDRD formula for calculating GFR, with cut-off value (5th percentile) based on result of studies performed in European Caucasians in screening for CKD and for establishing stages of CKD in BEN. Medical was used for statistical testing. Out of total number of examined inhabitants (603), 145 examinees were included in the second phase. After exclusion of 17 diabetic patients, 94 (73%) examinees from endemic and 34 (27%) examinees from non-endemic region remained. In the endemic region there were 46 (49%) examinees with and 48 (51%) without family burden for BEN. Overall GFR in examined groups was within physiologic range. There was not statistically significant difference in calculated GFR between examinees of endemic and non-endemic regions for BEN (Mann-Whitney test p=0.104; Fisher's test p=1), neither between examinees with and without family burden for BEN within endemic region (Mann-Whitney test p=0,7393; Fisher's test p=0,263). Overall GFR in examined groups was within physiologic range. There wasn't statistically significant difference in calculated GFR between examinees of endemic and non-endemic regions for BEN, neither between examinees with and without family burden for BEN within endemic region. GFR, no matter how accurately calculated and estimated, does not represent significant biomarker for diagnosis, especially early diagnosis, of BEN, until maybe its overt advanced form.

Balkan endemic nephropathy: an update on its aetiology

“…Intermittent proteinuria indicating proximal tubular damage can be found early, whereas in the uraemic stage of BEN, it becomes permanent. Loss of urine concentration capacity precedes a decrease in the glomerular filtration rate (Alecković et al 2010 ; Arsenović et al 2005 ; Dimitrov et al 2006 ).…”

Balkan endemic nephropathy--current status and future perspectives

“…The urinary sediment shows sparse white and red blood cells. In the early stages of BEN, the loss of urine concentration capacity precedes the decline in the glomerular filtration rate [ 15 – 17 ]. Serum proteins and immunoglobulins are unchanged.…”

Values of Alpha 1 Microglobulin Does Not Differ between Individuals with and without Family History of Balkan Endemic Nephropathy

“…Authors concluded that average kidney volume was bellow referent borderline values in all patients, even in the group (11 patients) with average GFR of 120.65 mL/min [ 22 ]. Twenty years later, as a part of our screening in endemic village Domaljevac, estimated GFR was found in the normal ranges regardless of family history of BEN [ 23 ].…”