**6. Conclusions**

to 145

C

effect on microalbuminuria was found [77, 149]. A cross-sectional study of 149 adult patients showed that those using hydroxyurea were less likely to exhibit albuminuria (defined as urinary urinary-creatinine ratios ≥30 mg/g) [149]. A multi-center trial in infants (mean age 13.8 months) demonstrated that treatment with hydroxyurea for 24 months did not influence the GFR. However, it was associated with better urine-concentrating ability and less renal enlargement, suggesting a possible renoprotective effect [41]. In a non-randomized study of children with SCD requiring hydroxyurea for standard indications, treatment for 3 years led to a mean (standard deviation (SD)) decrease in GFR from 167 (SD 46) mL/min/1.73 m2

Dietary protein restriction is not recommended, because of the underlying growth failure and

The use of multiple blood transfusions demonstrated to restore the urinary concentrating ability in children with SCD [152, 153]. One study of 120 children with sickle hemoglobinopathies found that chronic red blood cell transfusions before the age of 9 years was protective against the onset of microalbuminuria [154]. Blood transfusion receives HbS, prevent direct sickling in the kidney and vaso-occulsion, reducing glomerular and tubular ischemia damage to the kidney. However, the benefits of transfusion therapy must be balanced against risks including infections, iron overload, acute or delayed hemolytic transfusion

Hemodialysis is reportedly the leading form of renal replacement therapy for SCD-ESRD patients, as well as peritoneal dialysis and kidney transplantation. Mortality in SCD patients is approximately 26% during the first year of therapy for ESRD, nearly threefold higher than in ESRD patients without SCD. However, SCD patients who received pre-dialysis nephrology care had a lower death rate than those who did not receive such care [159].

Kidney transplantation may offer survival advantage over dialysis in ESRD. As in the general population, allograft survival for patients with ESRD is greater in those with a living donor than in those with a deceased donor. The post-transplantation one-year graft survival exceeds 60–80% [160]. Complications specific to the SCD population include higher infection risk due to autosplenectomy and precipitation of sickle cell crises with anemia correction following a successful transplant. Kidney transplant may be also complicated by allograft venous thrombosis, deep vein thrombosis, and vaso-occlusive crises [63, 161, 162]. Suggested maneuvers to decrease the incidence of post-transplant complications in these patients include [63, 163] preoperative blood transfusions to decrease hemoglobin S levels, preoperative oxygen supplementation with 40% oxygen, pretransplantation warming of the kidney allograft using 37<sup>o</sup>

saline, intraoperative and postoperative dopamine infusion at 4 μg/kg/min stem cell transplantation remain as the only curative treatment with good result and survival rates around 90% in

, indicating an improvement in the hyperfiltration [150].

(SD 27) mL/min/1.73 m2

170 Hematology - Latest Research and Clinical Advances

**5.3. Treatment of anemia**

reactions [48, 155–158].

4 years [164, 165].

**5.4. Treatment of end-stage renal disease**

decreased energy state in most patients with SCD [151].

SCN represents a new challenge in the treatment of acute and chronic complications in SCD. The underlying pathophysiology it is not completely understood, but it is already known that kidney damage occurs since the first months of life. The onset of hyperfiltration and albuminuria is an opportunity to intervene. The lack of diagnostic test capable of detecting the onset of symptoms remains a barrier to institute therapy. Furthermore, the absence of therapeutic strategy compounds the management of SCN. New markers of renal impairment in SCD such as the use of cystatin C assays may become available for community-based screening in order to identify patients at risk, to treat them and to improve their survival and quality of life.
