Ersin Akarsu

Relation between Serum Ubiquitin Levels and KT/V in Chronic Hemodialysis Patients

Accessible online at: www.karger.com/journals/nef Dear Sir, Ubiquitin, which is localized within the nucleus and cytoplasm of eukaryotic cells, comprises 76 amino acids with a molecular weight of 8.6 kD [1]. The ubiquitin-mediated proteolysis, a major pathway for selective protein degradation, plays a variety of regulating roles in cellular processes, including stress response and apoptosis. The main aim of the ubiquitination is to eliminate the harmful effects on cells [2]. Okada et al. [3] reported that ubiquitin serum levels in hemodialysis (HD) patients were high and have suggested that this is related to both amyloidosis and duration of dialysis. An increase of plasma ubiquitin levels in patients with chronic renal failure is also partly associated with decreased renal elimination [2]. On the other hand, adequate dialysis has a positive effect on protein catabolic rate (PCR) and lean body mass, and urea kinetic model parameters are accepted as good markers in evaluating dialysis efficiency [4].

THE IMPORTANCE OF SERUM TRANSFERRIN RECEPTOR LEVEL IN THE DIAGNOSIS OF FUNCTIONAL IRON DEFICIENCY DUE TO RECOMBINANT HUMAN ERYTHROPOIETIN TREATMENT IN HAEMODIALYSIS PATIENTS

In haemodialysis (HD) patients, functional iron deficiency frequently appears due to recombinant human erythropoietin (r-HuEPO) treatment. However, the diagnosis of iron deficiency is not always easy in such patients. Recent studies have shown that the serum transferrin receptor (s-TfR) level is a sensitive, quantitative measure of tissue iron deficiency. In this study, we examined the changes in s-TfR levels in patients with iron deficiency anaemia due to r-HuEPO treatment.We compared s-TfR levels of 24 patients with i.v. administered r-HuEPO 50–70 U/kg/dose) at the end of each dialysis session (three times a week) and diagnosed as having iron deficiency anaemia by routine laboratory methods (ferritin<50 μg/l and transferrin saturation<16%) with s-TfR levels of 32 patients not receiving r-HuEPO and without iron deficiency anaemia. Also, 40 healthy volunteer subjects were included in the study as a control group. Serum ferritin and transferrin receptor levels were measured with ELISAs using monoclonal reagents. There were no differences between the two groups with and without iron deficiency anaemia with respect to mean age, body weight, haemodialysis duration, haemoglobin and serum creatinine levels (p>0.05). For s-TfR levels, while no difference was present between the control and the non-iron deficiency groups (p>0.05), the iron deficiency group had higher s-TfR values than those of both the control and non-iron deficiency groups (p<0.001). Besides, there was an inverse correlation between haemoglobin and s-TfR levels in patients with iron deficiency anaemia (r=−0.85, p<0.0001).We conclude that the measurement of s-TfR levels may be useful in the diagnosis of functional iron deficiency in haemodialysis patients receiving r-HuEPO.

Iodine deficiency and goiter prevalence of the adult population in Erzurum.

It is believed that total goiter prevalence in Turkey is as high as 30.5%. The iodine deficiency is the distinct etiologic factor in the development of goiter. The aim of this study was to determine goiter prevalence and iodine deficiency in adults living in Erzurum (1659 m above sea level) for at least 10 year. The study involved 340 people (192 females, 148 males). The median age was 38.5 year (ranging from 20 to 76 years). Ultrasound-measured thyroid volume (TV) for men (TV>25 ml) and for women (TV>18 ml) was considered goiter indicator. By this evaluation, goiter was diagnosed in 94 (27.6 %) cases, whereas the goiter prevalence, based on the palpation method, was 5.6%. Urinary iodine concentration (UIC) was measured by ammonium persulfate method. UIC in subjects with goiter was significantly lower than that of the others (median values 5.0 vs 7.8 microg/dl, p<0.0001). While the value of UIC > or = 10 microg/dl (no. 121, 36.6%) was accepted normal, the extent of iodine deficiency in other subjects was classified as severe (UIC<2.0 microg/dl, no.53, 15.6%), moderate (UIC=2.0-4.9 microg/dl, no.75, 22%) and mild (UIC=5.0-9.9 microg/dl, no.91, 26.8%). TV values were found to be significantly different among the four groups (p<0.05). TV values were significantly correlated with body surface area and UIC (r=0.15 and r=-0.16, respectively, p<0.005). Also, the prevalence of thyroid nodules was estimated as 2.1% by palpation and 18% by ultrasonography. We conclude that goiter originating from iodine deficiency has been an important health problem in Erzurum. Besides taking measures at national level, local factors and risks which interfere with the nationwide efforts should also be dealt with for the eradication of the iodine deficiency problem. In the region, periodical evaluation of iodine level and iodine related disorders will guide the measures to be taken for the well being of peoples general health.

ALTERED BONE METABOLISM IN PATIENTS WITH INFLAMMATORY BOWEL DISEASE

Patients with inflammatory bowel disease (IBD) are at risk of developing metabolic bone disease. We aimed to compare markers of bone metabolism and bone mineral density in patients with IBD and healthy subjects. Seventeen patients with ulcerative colitis (13 women, four men; median age 33.4; range 15–52), and eight patients with Crohns disease (five women, three men; median age 30.2; range 21–44), and 20 healthy subjects (12 women, eight men; median age 32.5; range 17–52) were investigated.