Pruritus, defined as an unrestricted and uncomfortable sensation that elicits the desire to scratch, has been well recognized as a common complication in patients with chronic Renal failure [2-6]. It has been found that 15%-49% of patients with predialysis chronic renal failure and 50%-90% of those on hemodialysis or CAPD have pruritus [7].

In 2012, over 2500 patients received hemodialysis (HD) in the Bosnia and Herzegowina [17], in USA about 384,000 [7], and in Germany about 63,300 patients per year depend on HD [8]. It is estimated that worldwide more than 2 million people suffer from end-stage renal disease (ESRD) that requires HD.

Pruritus may be localized or disseminated and is the most common symptom of ESRD. It occurs in about 53% of these patients, causing great harm to their quality of life [2,10,11]. It is not associated with other primary or systemic skin diseases, psychological disorders or acute renal failure. The pathogenesis is not fully known, but there is a relation with hyperparathyroidism, xerosis, hypervitaminosis A, iron deficiency anemia, and elevated serum levels of magnesium, calcium, phosphate, aluminum and histamine, though the latter may be associated with allergic sensitization to components in dialysis membranes. Pruritus contributes to the appearance of perforating injuries by the Koebner phenomenon [12-16].

Moreover, there is no relationship between the plasma level of PTH and dermal Cell proliferation, nor is there a difference in the number of mast cells or the levels of PTH between patients with or without pruritus.

The pathophysiology of pruritus is multifactorial. Until now, studies reported significant association between serum parathyroid hormone (PTH) and the itching; some other studies have found no specific relationship between pruritus and hyperparathyroidism, hypercalcemia, hyperphosphatemia, and level of PTH [5,9,14,23].

This cross-sectional study was conducted on sixty and two patients with ESRD (age ranging from 31 to 87 years) free from systemic, skin or psychiatric disorders and other secondary causes attributable to pruritis, undergoing maintenance HD at Fresenius dialysis center, Banja Luka, Bosnia and Herzegovina were evaluated for pruritus and included in a study during period from December, 2013 to May, 2014. Duration of each session was 4 hours.

Those with history of dermatologic disease or chemical exposure were excluded. Patients were asked to report the severity of their pruritus.

Blood samples were taken from all patients for assessment of serum levels of phosphate, PTH, KT/V (index of dialysis dose), parameters at the beginning of the study and six months after.

The overall prevalence of pruritus in the present study is 45,2%.

Pruritus has been discovered in 21 out of 34 males (54,8%) and 6 out of 28 females (22,2%).

Applying χ² test with Yates correction was highly statistically significant (χ² = 8.003, p = 0.005) by gender. Analysis of the gender revealed that pruritus was significantly more detected in men, as shown in Table 1.

According to patients’ age no significant differences were found (applying T-Test (Independent Samples), t = - 0.443, p = 0.659).

Applying the Mann-Whitney-U test, there was no statistically significant difference in the duration HD/months/by groups of patients with pruritus (n = 27, Md = 84.00) and those without pruritus (n = 35, Md = 75.00), U = 421.00 z = -0731, p = 0.465, r = 0.092 (Table 2).

Using the Mann-Whitney-U test, there was no statistically significant difference in KTV1 by groups of patients with pruritus (n = 27, Md = 1.56) and patients without pruritus (n = 35, Md = 1.65), U = 339.50, z = -1889, p = 0.059, r = 0.239), the laboratory determined the start of the study as shown in Table. 3.

Using the T-test for independent samples there was no statistically significant difference (t = - 1.166, p = 0.248) in KT/V2 examined groups of subjects, measured at the end of the study.

Using the Mann-Whitney-U test, there was no statistically significant difference of level Phosphate 1 in serum by groups of patients with pruritus (N = 27, Md = 1.42) and patients without pruritus (N = 35, Md = 1.33), U = 371.50, z = -1.434, p = 0.151, r = 0.182. The laboratory determined the start of the study as shown in Table 4.

Using the Mann-Whitney-U, test there was no statistically significant difference of level Phosphate 1 in serum by groups of patients with pruritus (N = 27, Md = 1.26) and patients without pruritus (N = 35, Md = 1.30), U = 456.50, z = -0.227, p = 0.820, r = 0.029, measured at the end of the study.

Using the Mann-Whitney-U test, there was no statistically significant difference in PTH 1 by groups of patients with pruritus (N = 27, Md = 194.50) and patients without pruritus (N = 35, Md = 245.80), U = 453.00, z = -0.277, p = 0.782, r = 0.035 as shown in Table 5.

Using the Mann-Whitney-U test, there was no statistically significant difference in PTH 2 by groups of patients with pruritus (N = 27, Md = 218.20) and patients without pruritus (N = 35, Md = 214.70), U = 455.00, z = -0.248, p = 0.804, r = 0.031.

By applying the Wilcoxon test of paired couples there was no statistically significant difference in patients with pruritus neither in the change of KT/V2 and KT/V1 (z = 0.000, p = 1.000), nor in the change of Phosphates2 and Phosphates (z = -1.261, p = 0.207) nor in the change of PTH2 and PTH2 (z = -0,505, p = 0.614)., that is the measured laboratory value at the beginning of the study as shown in Table 6.

By applying the Wilcoxon test of paired couples there was no statistically significant difference in patients without pruritus neither in the change of KT/V2 and KT/V1 (z = -1.720, p = 0.085), nor in the change of Phosphates2 and Phosphates ((z = -0.377, p = 0.706), nor in the change of PTH2 and PTH2 (z = -0.419, p = 0.675). measured at the end of the study as shown in Table 7.

We conducted the first study of uremic pruritus in Republic of Srpska (Bosnia and Herzegovina).

Our study as many others showed that pruritus is very common (45.2%) in HD patients.

The overall prevalence of pruritus among our study population is 45,2 % and it is comparable with the published reports [1,3-5,14,17-19,20-22,24].

Pruritus has been detected in 21 out of 34 males (54,8%) and 6 out of 28 females (22,2%).

Analysis of the gender revealed that pruritus was significantly more shown in men, and previous studies have shown no difference in gender [24].

Men in the DOPPS I and I Studies had UP more often than women. In contrast, Snit M. et al. report that UP occurred statistically significantly more often in women, in­dependent of method of renal replacement therapy [1,14].

In our study, we did not find any relationship between pruritus and duration of dialysis as seen in some previous studies [14,21,23,24].

Like most of other studies, we could not find any relationship between serum levels of phosphorus and UP in the patients’ [24].

Hyperparathyroidism has been proposed by some authors as a cause of uremic pruritus [24]. Hyperparathyroidism can stimulate mast cells to release histamine and can promote microprecipitation of calcium and magnesium salts in the skin. On the other hand, all of the patients with severe hyperparathyroidism do not have pruritus. Moreover, there is no relationship between the plasma level of PTH and proliferation of dermal cell, and there is no difference in the number of mast cells and the levels of PTH between patients with or without pruritus. On the other hand, a direct role for parathyroid hormone as a cause of uremic pruritus has been questioned because of the failure of intradermal injections of PTH analogs to produce pruritus, and because of negative immunohistochemical studies for PTH in the skin biopsy specimens [24].

Furthermore, no correlation between PTH levels and itching intensity was found in most studies [14,21,23].

In our study, we did not find any relationship between pruritus and the plasma level of PTH.

This first cross-sectional study describes key features UP in Republic of Srpska and results that the UP is significantly more common in men.

This study demonstrates that the serum level of PTH and phosphate isn’t associated with the incidence of pruritus in HD patients.