Up to now, detailed investigation of tubular function in patients with endemic nephropathy have been performed in the relatively small number of patients who have already been in chronic renal failure /3,4,5,9,15/. That is why we started this work with the aim to determine renal function of the patients suffering by endemic nephropathy in different stages of the disease, especially in the early stage of the disease. The study included 119 patients with endemic nephropathy who were grouped according to creatinine clearance values into four groups (Table 1). The first group covered the patients with normal crearinine clearance values, and other three covered the patients who were in the different stages of renal failure. The diagnosis of endemic nephropathy was established according to criteria given by Danilovic /7/ and Velimirovic /8/ after ruling out the known renal diseases. The results of clinical and laboratory examinations were processed by appropriate epidemiological and statistical techniques. The results proved that there was no significant difference between sexes of our patients (p>0,05). Objective examination reveals characteristic tan pale yellow with copperish glow on the cheeks, in 15,48% of our patients in the early stage of the disease, which is in accordance with the results of Velimirovic/8/. Among nephropathy patients 13% of them had kidney smaller than normal measured by sonography, and even 51% measured by static scintigraphy, in the early phase of the disease (Table 4, Table 5). The earlier works /11,12/ mainly supported that kidneys get smaller during renal insufficiency, and in the early phase of the disease kidneys have a normal size, whereas the later works indicated that even the patients with normal glomerular filtration have smaller kidneys/13,14,15,16/. The laboratory findings and urine analysis of this disease suggested absens of biochemical indicators of inflammation in endemic nephropathy patients (Table 2, Table 3), which is in accordance with the previous in investigations. We noticed correlation between ceatinine clearance values and values of serum beta 2 microglobulin (r==,56; p==,0002; Figure 1). It has been documented that with decreased of creatinine clearance values serum values of beta 2 microglobulin increased, in chronic renal failure /22/. Quantitative measuring of proteinuria shows values less than 1,0g/l in all examined patients. Proteinuria of tubular type has been described in endemic nephropathy/5,8,13,16/. Beta 2 microglobulinuria have been registered at 10,97% patients with normal creatinine clearance values (Table 7). Increased urinry contrecation of beta 2 microglobulin is generally accepted as an important feature of endemic nephropathy /19,20,21/. Glicosuria increased with the progression of the disease. Urine osmolallity of endemic nephropathy patients decreased with the progression of chronic renal failure (Table 6). 65,46% of the investigated patients of the first group, who were in the clinically early phase of the disease, had decreased urine osmolallity (measuring by coefficient of osmolallity U osm/Posm). The tubular reabsorbtion of the phosphate decreased with the progression of chronic renal failure and that correlation was statistically significant r<0,69; p<0,05; Figure 2). Fractional tubular excretion of sodium increased with the progression of endemic nephropathy (Table7). The obteined results of the function of proximal tubul are comparabile with the results of the other authors, but in the smaller number of patients /4,13,15,16/. Our results of functional investigations of kidney et patients with endemic nephropathy suggests primary tubular dysfunction, and reduced kidney size and that was registered in the early phase of the disease.
Comparison of Highly Sensitive CRP and Serum Creatinine as an Early Marker of Renal Impairment
