Nephrotic syndrome is the most common childhood kidney disease worldwide and can cause high blood cholesterol, blood clots and chronic kidney disease. The kidneys of children with nephrotic syndrome cannot keep essential proteins from being lost in the urine, and the resulting lower level of blood-proteins causes fluid to build up under the skin and around internal organs. The cause of most nephrotic syndrome cases is not known, but probably involves genetic tendencies and immune system dysfunction. Atopic eczema is a common (up to one in five children) debilitating skin disease that causes red itchy skin. Recent research suggests that atopic eczema could affect more than ones skin and may be associated with increased risks of conditions like heart disease, diabetes and mental disorders. There have been previous reports that eczema and other allergic conditions are associated with nephrotic syndrome, but we dont fully understand if this was just a chance association. We plan to use health record data from UK primary care to explore if nephrotic syndrome is more likely to occur in children (aged under 18 years) with atopic eczema, compared to children without eczema. The results of this study could improve our understanding of why children get nephrotic syndrome, and what might happen to children with eczema (beyond the skin).
We aim to explore the association between atopic eczema and incident nephrotic syndrome. Atopic eczema is common in the UK, and all but the most severe cases (97%) are treated in primary care. We will be able to ascertain the presence of atopic eczema through the use of a validated algorithm. Nephrotic syndrome is a distinct clinical diagnosis with a small number of related diagnostic codes. To explore the association between atopic eczema and nephrotic syndrome, we will conduct a matched case-control study. We will include all children aged 1-17 years old in CPRD between 1999 and 2018 who had had a first diagnosis of nephrotic syndrome and match each one of them with up to five children of the same age, sex and GP practice, registered in the same time period. We will fit conditional logistic regression models to explore the association between atopic eczema and new diagnoses of nephrotic syndrome, adjusted for age, sex, and socioeconomic status. We will also explore the strength of this association specifically among children with concomitant asthma and atopic eczema and by the severity of atopic eczema, and through a range of sensitivity analyses.
Incident nephrotic syndrome diagnosis
Dorothea Nitsch - Chief Investigator - London School of Hygiene & Tropical Medicine ( LSHTM )
Yochai Schonmann - Corresponding Applicant - London School of Hygiene & Tropical Medicine ( LSHTM )
Amanda Roberts - Collaborator - Nottingham Support Group for Carers of Children with Eczema
Amy Mulick - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Daniel Prieto-Alhambra - Collaborator - University of Oxford
Kathryn Mansfield - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Liam Smeeth - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Masao Iwagami - Collaborator - University of Tsukuba
Sinead Langan - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation