**5.2. Treatment of proteinuria**

The benefits of angiotensin-converting enzyme (ACE) inhibitors and angiotensin-II receptor blockers (ARB) in slowing kidney disease progression in many situations are well-known. Improving nocturia has been reported to be an additional beneficial effect of ACE, presumably as a result of reduction in GFR [148]. A recent Cochrane database review, in 2015, reported the potential for reduction in albuminuria and proteinuria with the use of captopril in patients with SCD compared with those without the disease [148]. However, the administration of ACE and ARB should be carried out carefully due to the risk of hypotension and hyperkalemia, the latter condition often present in SCD patients.

The use of hydroxyurea (HU) has been suggested to reduce proteinuria and hyperfiltration as suggested in one prospective study consisting of 26 patients with SCD. However, no 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 to 145 (SD 27) mL/min/1.73 m2 , indicating an improvement in the hyperfiltration [150].

**6. Conclusions**

**Acknowledgements**

help and suggestions.

**Competing interests**

**Authors' contributions**

**Author details**

Baba P.D. Inusa<sup>1</sup>

The authors declare that they have no competing interests.

discussed, read and approved the manuscript.

St Thomas NHS Trust, London, UK

\*, Lodi Mariachiara2

\*Address all correspondence to: baba.inusa@gstt.nhs.uk

of North Carolina at Chapel Hill, Chapel Hill, NC, USA

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.

Sickle Cell Nephropathy: Current Understanding of the Presentation, Diagnostic and…

http://dx.doi.org/10.5772/intechopen.76588

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The authors thank Professor Lorenzo Iughetti, Donatella Venturelli and Elena Bigi for their

BI designed the draft of the chapter, BI and ML reviewed the literature and wrote the manuscript, BI, KA and GP reviewed and made the substantial changes the manuscript. All authors

, Palazzi Giovanni3

1 Paediatric Sickle Cell and Thalassaemia, Evelina London Children's Hospital, Guy's and

3 Oncology and Hematology Pediatric Unit, Department of Medical and Surgical Science for

4 UNC Comprehensive Sickle Cell Program, Division of Hematology/Oncology, University

2 Post Graduate School of Pediatrics, Department of Medical and Surgical Sciences for Mothers, Children and Adults, University of Modena and Reggio Emilia, Modena, Italy

Mothers, Children and Adults, University Hospital of Modena, Modena, Italy

and Kenneth I. Ataga4

Dietary protein restriction is not recommended, because of the underlying growth failure and decreased energy state in most patients with SCD [151].
