Urinary hydroxyproline and serum alkaline phosphatase in sickle cell disease

Area of Science:

• Biochemistry
• Hematology
• Pediatrics

Background:

• Sickle cell disease (SCD) is a genetic blood disorder.
• Bone complications are common in SCD patients.
• Alkaline phosphatase and hydroxyproline are markers of bone metabolism.

Purpose of the Study:

• To investigate serum alkaline phosphatase and urinary hydroxyproline levels in young adult sickle cell patients.
• To determine the predominant alkaline phosphatase isoenzyme in sickle cell patients.
• To explore the relationship between these markers and disease progression.

Main Methods:

• Measured serum alkaline phosphatase (total and isoenzymes) and urinary hydroxyproline excretion.
• Compared levels between 20 young adult sickle cell patients and 58 healthy controls.
• Utilized heat inactivation and isoenzyme electrophoresis for isoenzyme analysis.

Main Results:

• Sickle cell patients had significantly higher total alkaline phosphatase than controls.
• Bone alkaline phosphatase was the predominant isoenzyme in patients.
• Urinary hydroxyproline excretion was significantly elevated in sickle cell patients.
• A strong positive correlation (r=0.73) was found between serum alkaline phosphatase and urinary hydroxyproline.
• Both markers increased with age in sickle cell patients.

Conclusions:

• Elevated alkaline phosphatase and hydroxyproline in sickle cell patients suggest increased bone turnover.
• Delayed growth and/or bone destruction are likely contributors to these findings.
• These markers may serve as indicators of bone health status in sickle cell disease.