Drugs for preventing red blood cell dehydration in people with sickle cell disease
Abstract
Background
Sickle cell disease is an inherited disorder of haemoglobin, which results in abnormal red blood cells. These can deform and cause blockages in blood vessels, leading to acute crises such as pain; stroke and splenic sequestration; and chronic organ and tissue damage. Recently research has begun to focus on therapies which prevent the red blood cells deforming by reducing the loss of water and ions from the cells. However, little is known about the effectiveness and safety of such drugs.
Objectives
To assess the relative risks and benefits of drugs which aim to prevent sickle cell‐related crises by reducing red blood cell dehydration.
Search methods
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register which comprises of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.
Date of the most recent search of the Group's Haemoglobinopathies Trials Register: November 2006.
Selection criteria
Randomised or quasi‐randomised controlled trials of drugs which aim to prevent sickle cell crises by reducing red cell dehydration, compared to placebo or an alternative treatment.
Data collection and analysis
Both authors independently selected studies for inclusion, assessed study quality and extracted data from the included studies.
Main results
Of the 39 studies identified, one met the inclusion criteria. This study tested the effectiveness of zinc sulphate to prevent sickle cell‐related crises in a total of 145 participants and showed a significant reduction in the total number of pain, haemolytic, aplastic and sequestration crises over one and a half years, mean difference ‐2.83 (95% CI ‐3.51 to ‐2.15). However, our analysis was limited by non‐reporting of standard deviations for some data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in the study.
Authors' conclusions
While the results of zinc for reducing sickle‐related crises are encouraging, larger and longer‐term multicentre studies over a number of years are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.
PICOs
Plain language summary
Drugs that aim to reduce the loss of water from red blood cells in people with sickle cell disease
Sickle cell disease is an inherited condition that causes red blood cells to become sickle shaped when they lose water. This leads to a high risk of the blood vessels becoming blocked. Such blockages can cause pain, stroke and damage to organs. Recent therapies aim to stop the cells becoming sickle shaped by preventing them losing water. This review, which included one study of zinc sulphate, showed that this drug may be able to reduce the number of sickle cell crises without causing toxic effects. There were 145 participants in this study and results showed a significant reduction in the total number of serious sickle‐related crises over one and a half years, mean difference ‐2.83 (95% CI ‐3.51 to ‐2.15). However, our analysis was limited since not all data were reported. Changes to red cell measurements and blood counts were not consistent. No serious adverse events were noted in the study. More longer‐term research is needed on this drug and others that might prevent water loss in red blood cells.
