Background: The incidence of thalassaemia minor in end-stage renal disease patients is similar to that of the general population. Both these conditions are characterized by anaemia, but the underlying pathophysiology is quite different. Current literature lacks an adequate clinical survey of haemodialysis patients with thalassaemia minor.
Methods: The prevalence of thalassaemia minor (thal-m) in haemodialysis patients was assessed by a national survey collecting general information as well as clinical and haematological parameters. Data were also collected on the use of recombinant erythropoietin in these subjects. A dedicated questionnaire was sent to all Italian dialysis units.
Results: Only 116/705 dialysis units returned the questionnaire (16.4%): 33 units did not have any patients affected by thalassaemia minor. No response was obtained from six Italian regions whereas ten regions returned only partial answers. The response from four regions was satisfactory (20%) while the completed questionnaire was returned by all units in only two small regions. A total of 7731 ESRD patients were collected, 240 (3.1%) were also affected by thal-m, 142 males and 98 females. In the four regions with the highest response rates, Calabria 45%, Puglia 65%, Basilicata and Molise 100%, the prevalence of thal-m were 3.68%, 4.56%, 3.3% and 1%, respectively. A total of 3623 uraemic patients (47% of all enrolled subjects) were collected from these four regions. Here is the patient geographic distribution: northern Italy 2.16% (response rate of 9.44%); central Italy 1.69% (response rate of 7.64%), southern Italy 3.77% (response rate of 29.46%). The age range of thal-m patients was 17 to 90 years, the time spent on dialysis was between 3 and 384 months, the body weight was between 35 and 93 kg, the Hb value was between 6.2 and 13.6 g/dl, and the Htc value was between 19 and 44%. A total of 230 thal-m patients were on haemodialysis while 10 patients were on peritoneal dialysis (4.2%). The mean haemoglobin level for the thal-m group was 9.8+/-1.4 g/dl and for the control group the value was 11.4+/-1.4 g/dl (p < 0.0001). The use of rhEPO was on the average 7659+/-6256 u/wk for the thal-m and 4378+/-4435 u/wk for the control group (p < 0.0001). The bodyweight was 129+/-105 u/kg/wk (range 0-370). Finally, 17.9% of the thal-m patient did not use rhEPO, their Hb value was 10.66+/-1.67 g/dl (range 8.2-13). No patient went over 30 thousand units and only 4 had such dosage in therapy. The 12.1% thal-m patients with Hb < 10 g/dl did not use rhEPO. The need for rhEPO per gram of Hb was 796+/-722 u/wk in thal-m patients and 416+/-449 U/wk in control patients (p < 0.0001). Uraemic anaemia was corrected with 4.8 million red blood cells in the control group and with about 7.7 million red blood cells in the thal-m group.
Conclusions: Data from this national survey, although incomplete, show that rHuEpo is less effective in these patients and its use does not seems to be correct. It is important to emphasise that recent Guidelines do not recommend neither a specific treatment for these patients nor the use of r-HuEpo. However, it should also be underscored that most thal-m patients do not reach the target Hb level suggested by the National Guidelines for the general population in chronic dialysis.