Scientific summary

Chronic kidney disease affects approximately 10% globally and is associated with large costs for the society and great suffering for the affected patients. Glomerular diseases account for half of the disease cases, of which glomerulonephritis (mainly IgA nephritis, IgAN) and diabetic nephropathy (DN) are the two most common causes for renal replacement therapy in Sweden. As a result of increased lifespans and more people suffering from lifestyle-related diseases, the incidence of IgAN and DN is expected to rise dramatically. The escalating global warming is also increasing the risk of Mesoamerican nephropathy (MeN)/chronic kidney disease of unknown cause (CKDu), a diagnosis that predominantly affects young agricultural workers in warm countries.

Large individual differences in symptoms and disease course, as well as the lack of individually tailored treatment strategies in patients with chronic kidney disease, constitute a major challenge for healthcare. The outcome of renal transplantations in Sweden are in general very good. However, the long-term results are still unsatisfactory as many patients lose their grafts due to recurrence of renal disease or chronic rejection (eg chronic transplant glomerulopathy, TG).

To better understand how to treat and prevent IgAN, DN, MeN/CKDu and TG, but also other important kidney diseases affecting native kidneys and kidney transplants, we initiated a large healthcare-integrated study on kidney tissue, blood and urine in 2010. The aim was to create a detailed map of both biomolecular and clinical data in relation to the disease picture and development over time. This prospective study lays an important foundation for the development of future precision medicine regimes with more accurate diagnostics and risk assessment, as well as tailored treatments with fewer side effects. The ultimate goal is to improve the prognosis of each individual patient, contribute to better resource utilization in healthcare and to reduce costs for society.

Our goal

To obtain new knowledge of significant structural, genetic and biological markers for onset, progression and treatment of kidney diseases. Our research, which includes various diseases affecting native kidneys but also kidney transplants, aims to facilitate diagnosis at earlier stages, individualized treatments, and simplify follow-up – thereby reducing the risks associated with chronic kidney disease (CKD) and the need of kidney replacement therapy, including dialysis or kidney transplantation.

Project background

In our project, experienced clinicians collaborate with internationally recognized basic science researchers to gain new knowledge about disease mechanisms and new diagnostic methods in CKD. We have systematically created a unique biobank repository with kidney tissue, blood and urine from patients with CKD caused by various etiologies, which are all linked to longitudinal clinical outcome data. The combination of patient data with modern profiling technologies and careful histopathological investigations of kidney biopsies provides an important foundation for designing future diagnostic tools and individualized treatments (ie precision medicine). A close collaboration between the clinics, clinical researchers and basic scientists both at Karolinska Institutet, Gothenburg University and Astra Zeneca allows a fast route for implementation into clinical praxis. In an international part of the project, we collaborate with several local researchers to investigate a quite recently described disease entity, often named Mesoamerican Nephropathy or Chronic kidney disease of unknown cause (CKDu), which mainaly affects young men working at sugarcane plantages (Central America) and in other agricultural work. It is of great importance to find out if it is the same disease in all affected areas and to identify pathogenetic mechanism(s) to enable preventive work in these middle income countries.

Overview of biobank and techniques

Patient registry: Patients with CKD that undergo a kidney biopsy at Karolinska University Hospital Huddinge for clinical reasons are included in a consecutive order, about 75-100 patients per year. Information regarding previous medical history and medications are collected. Glomerular filtration rate (GFR) is determined by iohexol clearance and patients undergo anthropometric measurements of body composition, e.g., DEXA. Patients are asked to answer several lifestyle questionnaires, including questions about diet, intake of medicines/drugs and quality of life. Healthy kidney donors are recruited at the transplantation unit at Karolinska University Hospital Huddinge serving as control subjects. In total, approximately 1050 subjects have been included so far.

Tissue resources: Kidney biopsies, blood and urine are collected at baseline. At the time of kidney biopsy or transplantation, kidney tissue is immediately prepared to optimize preservation of morphology, antigen- and RNA integrity. The control biopsy is obtained within 3 minutes after the arterial circulation to the kidney is obstructed to avoid ischemic damage.

Histopathology and immunohistochemistry: To identify pathological changes and localize selected proteins tissue sections are examined with light microscopy,immunostaining techniques and electron microscopy (EM).

Ultrastructural analyzes: All biopsies are evaluated ultrastructurally. ImmunoEM (iEM) is used to localize and quantify proteins in the various structural parts of the kidney with great precision. Antibodies directed towards selected structural proteins are detected by gold-conjugated protein A, which are semi-quantitated and subsequently correlated to structural changes.

RNA sequencing: RNA is isolated from microdissected glomeruli or from other (remaining) tissue, mainly consisting of tubuli, and analyzed with RNA sequencing (bulk and single cell).

Metabolomics and proteomics: Integrated analyses of clinical variables and high-resolution biomolecular data from tissue, blood and urine are performed to gain a deeper insight that extends beyond conventional biomarkers.

Biomarker analyzes in blood and urine: Metabolic, renal, aging, cardiovascular and inflammatory markers in blood, plasma/serum and urine are analyzed with routine methods or commercial assays.

Prospective data: All participants are invited to follow-up investigations, including blood and urine sampling, at 2, 5 and 10 years after biopsy/transplantation.

Functional studies: Interesting genes/proteins will be further studied in knock-down/in established mice and rat models of CKD (PAN and Adriamycin- nephrosis and animal models for diabetes).

Principal Investigators

Lead principal investigator: Annika Östman Wernerson, Professor /MD, CLINTEC, Karolinska Institutet /Clinical pathology and cancer diagnostics Unit, Karolinska University Hospital, Huddinge.

Peter Barany, Associate professor/MD, CLINTEC, Karolinska Institutet/Renal Pediatrics Unit, Karolinska University Hospital Huddinge.

Annette Bruchfeld, Professor/MD, Department of Health, Medicine and Caring Sciences, Linköpings universitet. Guest professor, CLINTEC, Karolinska Institutet.

Maria Herthelius, Associate professor/MD, CLINTEC, Karolinska Institutet/Renal Pediatrics Unit, Karolinska University Hospital Huddinge.

Lars Wennberg, Associate professor/MD. CLINTEC, Karolinska Instiutet/ Renal transplantation Unit, Karolinska University Hospital Huddinge.

Contributing researchers (in alphabetical order)

Thomas Ebert, MD, CLINTEC, Karolinska Institutet

Karolina Kublickiene, Associate professor/MD, CLINTEC, Karolinska Institutet

Torbjörn Lundgren, Associate professor/MD. CLINTEC, Karolinska Institutet/Renal transplantation Unit, Karolinska University Hospital Huddinge

Hannes Olauson, MD/PhD. CLINTEC, Karolinska Institutet/Clinical pathology and cancer diagnostics Unit, Karolinska University Hospital Solna

Jaakko Patrakka, Adjunct professor/MD, LABMED, Karolinska Institutet /Clinical pathology and cancer diagnostics Unit, Karolinska University Hospital Huddinge.

Angelina Schwarz, PhD. Post Doc, CLINTEC, Karolinska Institutet

Peter Stenvinkel, Professor/MD. CLINTEC, Karolinska Institutet/Renal Medicine, Karolinska University Hospital Huddinge

Julia Wijkström, PhD/MD. CLINTEC, Karolinska Institutet/Renal Medicine, Karolinska University Hospital

Anna Witasp, PhD, CLINTEC, Karolinska Institutet

Regional collaborators (in alphabetic order)

Hans Blom, PhD, KTH Royal Institute of Technology

Hjalmar Brismar, PhD, KBH, Karolinska Institutet

Milan Chromek, MD, PhD, Karolinska Institutet

Ásta Dögg Jónasdóttir, MD, CLINTEC, Karolinska Institutet

Carl-Gustaf Elinder, Professor, CLINTEC, Karolinska Institutet

Ulf Eriksson, Professor, MBB, Karolinska Institutet

Helen Erlandsson, MD, PhD, Karolinska Institutet

Annelie Falkevall, MBB, Karolinska Institutet

Helena Genberg, MD, PhD, CLINTEC, Karolinska Institutet

Olof Heimburger; MD, Associate professor, CLINTEC, Karolinska Institutet

Kjell Hultenby, Associate professor, LABMED, Karolinska Institutet

Marie Jeansson, MD, MedH, Karolinska Institutet

Sigrid Lundberg, MD, Associate professor, KIDS, Karolinska Institutet

Abdul Rashid Qureshi; MD, PhD, CLINTEC, Karolinska Institutet

David Unnersjö-Jess, PhD, CLINTEC, Karolinska Institutet

PhD students

Anna Levin, MD

Emelie Westergren, MD

Johan Nordström, MD

Jessica Smolander, MD

National collaborators

Jenny Nyström, Professor, Göteborgs Universitet

Kerstin Ebefors, PhD, Göteborgs Universitet

Johan Mölne, Associate professor, Sahlgrenska Universitetssjukhuset/Göteborgs Universitet

Bengt Fellström, Professor, Akademiska sjukhuset/Uppsala Universitet

Inga Soveri, Associate professor, Akademiska sjukhuset/Uppsala Universitet

Magnus Söderberg, PhD, AstraZeneca Göteborg

Anna Reznichenko, PhD, AstraZeneca Göteborg

Kristina Jakobsson, Professor, Göteborgs Universitet

International collaborators

Ricardo Leiva, MD, Hospital Nacional Rosales, El Salvador.

Marvin Gonzalez, PhD, National Autonomous University of Nicaragua at Leon, Nicaragua.

Channa Jayasumana, PhD, Rajarata University of Sri Lanka, Sri Lanka.

Vidhya Venugopal, Professor, Sri Ramachandra Institute of Higher Education and Research, Chennai, India.

Richard J. Johnson, Professor, University of Colorado Anschutz Medical Campu, USA

Magdalena Madero, Institution Nacional de Cardiologi, Mexico.

We are also connected to The Consortium for the Epidemic of Nephropathy in Central America and Mexico (CENCAM)