A study of genetic and environmental factors associated with kidney disease in people of African ancestry living in the UK

ISRCTN ISRCTN17433656
DOI https://doi.org/10.1186/ISRCTN17433656
IRAS number 292365
Secondary identifying numbers IRAS 292365, CPMS 52421
Submission date
04/05/2022
Registration date
05/05/2022
Last edited
16/04/2025
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Urological and Genital Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
People of African or Afro-Caribbean ancestry are five times more likely to have kidney disease. They also develop kidney failure when they are about 10 years younger than white people. The connection between ethnicity and kidney disease is complex.
A gene pattern (APOL1-G1/G2 alleles) has been found which is common in people of African and Afro-Caribbean ancestry. We think this gene pattern prevents some forms of sleeping sickness which is why so many people of West African and Afro-Caribbean ancestry have these gene patterns. This gene pattern may make it more likely for some people to develop kidney disease (including particular types of disease: focal segmental glomerulosclerosis (FSGS), hypertensive-associated kidney disease). We do not completely understand why some people with these gene patterns develop kidney disease while others do not. We think there are additional factors including extra genetic changes and/or environmental triggers e.g. infection which lead to onset of kidney disease.
We would like to test your blood, urine and kidney tissue (if you have previously had a kidney biopsy) to get more information. This will allow us to develop tests to predict who is going to have kidney damage and find ways to prevent damage. You do not need to have a kidney biopsy if you have not already had one as part of your clinical care.

Who can participate?
For CKD Group:
You are of African or Afro-Caribbean ancestry and have kidney disease. This means that either your kidneys work less well than expected or that your kidneys leak protein or blood into your urine.
For Control Group:
You are of African or Afro-Caribbean ancestry and DO NOT have kidney disease

What does the study involve?
You will see one of the doctors or nurses who will answer any questions that you may have. If you agree to take part, we will ask you to sign a consent form and you will be given a copy to keep. We will then take extra blood, and urine from you. We will take a minimum of one extra blood test from you and we will try to do these tests when you attend your normal appointments so you will not have any extra visits to the hospital or extra needles. We will take no more than 40 ml of blood from you at one point (4 tablespoons). There will be no repeat blood tests after this. We will also look at relevant medical records.
If you have had a kidney biopsy we will ask for your permission to retrieve any spare tissue that is available from storage for testing. You will not be asked to have any more kidney biopsy samples taken.

What are the possible benefits and risks of participating?
Your samples and information may help us to improve the treatment of people of African or Afro-Caribbean ancestry with kidney disease in the future.

There are no risks to you by taking part. The amount of extra blood that we take will not affect you. Occasionally people experience pain or bruising from having blood taken, but we will try to do this at the same time as your routine blood tests to minimise discomfort.

Where is the study run from?
The study will be running in the Renal Unit of King's College Hospital NHS Foundation Trust (UK)

When is the study starting and how long is it expected to run for?
March 2022 to November 2024

Who is funding the study?
The study is co-sponsored by King’s College Hospital NHS Foundation Trust and Kings College London and funded by AstraZeneca (UK).

Who is the main contact?
1. Dr Kate Bramham, kate.bramham@kcl.ac.uk
2. Amrita Ramnarine, amrita.ramnarine@kcl.ac.uk
3. Dalvir Kular, dalvir.kular@kcl.ac.uk

Contact information

Dr Kate Bramham
Principal Investigator

King's College Hospital NHS Foundation Trust
Renal Unit
Denmark Hill
London
SE5 9RS
United Kingdom

ORCiD logoORCID ID 0000-0002-6272-7921
Phone +44 203 299 6233
Email kate.bramham@kcl.ac.uk

Study information

Study designMulticentre observational cohort
Primary study designObservational
Secondary study designCohort study
Study setting(s)Hospital
Study typeOther
Participant information sheet 41696 APPLE CKD PIS Case V1.1 25Apr2022.pdf
Scientific titleAPolipoprotein L1 in People of African ancestry Living in the UK: Exploration of genetic and environmental factors associated with Chronic Kidney Disease (APPLE-CKD)
Study acronymAPPLE-CKD
Study objectivesPrimary:
To establish if epigenetic DNA methylation patterns in the APOL1 gene promoter in renal tissue are comparable to peripheral blood mononuclear cells PBMC (or spleen) and urine in participants with CKD and controls (including deceased kidney donors) with APOL1 high and low-risk genotypes

Secondary:
1. To study the role of APOL1 genetics and epigenetics in the differentiation of inducible Pluripotent Stem Cells into kidney relevant cells
2. To develop a ‘clinical/genetic/epigenetic/inflammatory signature’ associated with CKD in people of African ancestry with validation
Ethics approval(s)Approved 03/05/2022, North West - Greater Manchester West Research Ethics Committee (Barlow House, 3rd Floor, 4 Minshull Street, Manchester, M1 3DZ, UK; +44 2071048007; gmwest.rec@hra.nhs.uk), ref 22/NW/0100
Health condition(s) or problem(s) studiedExploration of genetic and environmental factors associated with chronic kidney disease in patients of African ancestry
InterventionIn the study, plasma, serum, urine, pre-existing renal tissue and peripheral blood mononuclear cells (PBMC) will be collected from patients. These will be sent for further analyses for:
1. Genotyping and epigenetic analysis - for PBMC (spleen MCs), renal biopsy tissue, urine pellets cases and controls
2. APOL1 and inflammatory marker analysis - for plasma, serum, renal biopsy tissue, urine supernatant and urine pellets
3. Inducible Pluripotent Stem Cell (iPSC) analysis - for the cryopreserved PBMCs
Intervention typeGenetic
Primary outcome measureAt a single time point:
1. APOL1 promoter DNA methylation patterns in renal tissue and PBMC (spleen) and urine (Cases only) measured using standard laboratory analysis
2. CKD disease phenotype measured using standard laboratory analysis
Secondary outcome measuresAt a single time point:
Clinical characteristics from patient notes and laboratory records, inflammatory markers measured using novel proteomic methods
Overall study start date01/03/2022
Completion date30/11/2024

Eligibility

Participant type(s)Healthy volunteer, Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants240
Key inclusion criteriaCKD cases:
1. Self-reported African ancestry
2. Aged ≥18 years
3. Willing and able to provide written informed consent
4. Chronic kidney disease (KDIGO Criteria)
5. Group 1: Without diabetic nephropathy or serological or biopsy-proven evidence of immune-mediated kidney disease
6. Group 2: With diabetic nephropathy or serological or biopsy-proven evidence of immune-mediated kidney disease

Controls:
1. Self-reported African ancestry
2. Aged ≥18 years
3. Willing and able to provide written informed consent
4. No CKD (estimated GFR >60 ml/min/1.73m² and urinary protein: creatinine <15mg /mol or albumin: creatinine ratio <3 mg/mmol or negative urine dip for protein).
Key exclusion criteriaFor both CKD cases and controls:
1. Unable to provide informed consent
2. Pregnancy
Date of first enrolment01/06/2022
Date of final enrolment01/11/2024

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centres

King's College Hospital NHS Foundation Trust
Denmark Hill
London
SE5 9RS
United Kingdom
Guys Hospital
Guys Hospital
Great Maze Pond
London
SE1 9RT
United Kingdom

Sponsor information

King's College Hospital NHS Foundation Trust
Hospital/treatment centre

Renal Unit
Denmark Hill
London
SE5 9RJ
England
United Kingdom

Phone +44 20 3299 6625
Email rahman.ahmed1@nhs.net
Website https://www.kch.nhs.uk/
ROR logo "ROR" https://ror.org/01n0k5m85
King's College London
University/education

Health Schools (Research Management & Administration Office)
Room 5.31, James Clerk Maxwell Building
57 Waterloo Road
London
SE1 8WA
England
United Kingdom

Phone +44 (0)207 8483224
Email reza.razavi@kcl.ac.uk
Website http://www.kcl.ac.uk/index.aspx
ROR logo "ROR" https://ror.org/0220mzb33

Funders

Funder type

Industry

AstraZeneca
Government organisation / For-profit companies (industry)
Alternative name(s)
AstraZeneca PLC, Pearl Therapeutics
Location
United Kingdom

Results and Publications

Intention to publish date01/11/2025
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryData sharing statement to be made available at a later date
Publication and dissemination planThe research team plans to disseminate the study research findings in the following settings:
• Conference presentation of study process and results at UK Kidney Week, American Society of Nephrology Conference or the European Renal Association conference and International Society of Nephrology.
• Publication of results in a renal recognised high impact journal.
IPD sharing planThe data-sharing plans for the current study are unknown and will be made available at a later date

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Participant information sheet Cases
version 1.1
25/04/2022 05/05/2022 No Yes
Participant information sheet Controls
version 1.1
25/04/2022 05/05/2022 No Yes
Protocol file version 1.1 25/04/2022 05/05/2022 No No
HRA research summary 20/09/2023 No No

Additional files

41696 Protocol V1.1 25Apr2022.pdf
41696 APPLE CKD PIS Control V1.1 25Apr2022.pdf
Controls
41696 APPLE CKD PIS Case V1.1 25Apr2022.pdf
Cases

Editorial Notes

16/04/2025: Royal London Hospital and Associated Community Services NHS Trust was removed as a study participating centre.
10/10/2024: Guys Hospital and Royal London Hospital and Associated Community Services NHS Trust were added to the study participating centres.
20/09/2023: A link to the HRA research summary was added.
07/06/2022: Internal review.
05/05/2022: Trial's existence confirmed by North West - Greater Manchester West Research Ethics Committee.