INTERNATIONAL IgA NEPHROPATHY NETWORK
&
RENAL PATHOLOGY SOCIETY
In collaboration with the International Society of Nephrology
CONSENSUS ON PATHOLOGY OF IgA NEPHROPATHY
Consensus Meeting on the Clinico-pathological Classification of IgA Nephropathy
Magdalen College, Oxford
14-16 September 2005
MEETING SUMMARY
Attendees
Nephrologists
Jonathan Barratt [UK]
Francois Berthoux [France]
Daniel Cattran [Canada]
Rosanna Coppo [Italy]
Guiseppe D'Amico [Italy]
John Feehally [UK]
Ron Hogg [USA]
Stephen Hsu [USA]
Tetsuya Kawamura [Tokyo]
CB Leung [Hong Kong]
Paolo Schena [Italy]
Stephan Troyanov [Canada]
Pathologists
Charles Alpers [USA]
Jan Bruijn [Netherlands]
Terry Cook [UK]
Vivette D'Agati [USA]
Steven Emancipator [USA]
Franco Ferrario [Italy]
Agnes Fogo [USA]
Mark Haas [USA]
Andrew Hertzenberg [Canada]
Prue Hill [Australia]
Kensuke Joh [Japan]
Fernand Lai [Hong Kong]
Ian Roberts [UK]
Patrick Walker [USA]
Helen Price [Aspreva Pharmaceuticals]
Charles Pusey [Kidney Research UK]
Apologies:
Bob van Es [Netherlands]
Sandrine Florquin [Netherlands]
Hermann-Josef Groene [Germany]
Charles Jennette [USA]
Philip Li [Hong Kong]
Yasuhiko Tomino [Jaoan]
Jan Weening [Netherlands]
Background
This meeting was developed by the International IgA Nephropathy Network [IIgANN] supported by the Renal Pathology Society [RPS]. Sponsorship for the meeting came from the International Society of Nephrology, Aspreva Pharmaceuticals Limited, and the UK National Kidney Research Fund.
The meeting built on a first meeting of the group held in St Louis on 31st October 2004 and a subsequent gathering of pathologists at the USCAP meeting in San Antonio, 26th February 2005.
The goals and strategy of the group have previously been published for comment on the websites of IIgANN and RPS.
Overall purpose and strategy
We agreed that our goal was to develop a new clinico-pathological classification for IgA nephropathy which would become internationally accepted. The purpose of this new classification would be to identify the risk of progression of renal disease in IgAN thus enabling us to
- Improve individual patient prognostication
- Identify potential for response to immunosuppression or other specific treatments
- Refine recruitment to clinical trials
The strategy is to agree a wide range of pathological parameters which may be associated with prognosis, and score these in well-characterised cases selected from across the world. There will then be a statistical analysis of the clinico-pathological correlations, following which a classification will be proposed, which will be evaluated on further cases in an iterative process before publication and dissemination.
Meeting goals achieved and proposals for future work
The meeting achieved the following goals which had been set beforehand.
1. Agree definitions of each pathological criterion to be scored
2. Agree the pathological scoring system and scoring sheets
3. Agree the pathological material to be circulated
Anonymised biopsy material will include
- PAS – mandatory: minimum number of 10 glomeruli on PAS section.
- H&E - preferred.
- Methanamine silver - preferred.
- Trichrome - preferred.
- Biopsy report including immunofluoresence and EM reports where available.
4. Agree patient cohorts to be evaluated
- An initial cohort of 40 cases will be circulated among the pathologists to refine and verify the scoring system.
- The main cohort will consist of 300 cases – approximately 50 children, 250 adults. Each adult centre will initially be asked to provide 30 cases.
- Approximately 100 cases will come from each of Asia, Europe, and North America.
- Patients with HSP, diabetes and other known renal disease will be excluded.
- Inclusion criteria (information collected within three months of renal biopsy)
- estimated GFR > 30ml/min/1.73m 2
- Proteinuria - adults >1g/24hrs (no upper limit); children aged <18 years >0.5g/24hrs/1.73m 2 or protein creatinine ratio >0.5/1.73m 2 .
- There will be no restriction on past or present medication. There was detailed discussion about the risks and benefits of including patients who had received corticosteroids or other immunosuppressive agents. It was decided such patients should not be excluded. It was agreed that any unit which used such medications extensively should not include within its submitted cohort >25% of patients who had received such treatment. The advantage of using patients from placebo arms of previous controlled trials, or from units which did not use corticosteroids (thus including cases with histological risk factors which in other units would invoke corticosteroid or immunosuppressive treatment) was noted.
- Each case should have at least five years follow up with a minimum of five follow up datasets consisting of proteinuria, blood pressure and serum creatinine.
5. Process for identification of cases
The following centres have indicated in principle their willingness to contribute.
Asia – Adults |
Hong Kong P Li |
Juntendo University, Tokyo Y Tomino |
Chiba City University K Joh |
Beijing H Wang |
Asia - Children |
Tokyo N Yoshizawa |
Europe - Adults |
Milano G D'Amico |
Bari P Schena |
St Etienne F Berthoux |
Glasgow C Geddes |
Leicester J Feehally |
Europe - Children |
EU Group R Coppo |
North America – Adults |
Toronto D Cattran |
SW Study Group R Hogg |
Mayo Clinic F Ferenza |
North America - Children |
SW Study Group R Hogg |
6. Agree clinical datasets
These were agreed after some further minor refinements of the datasets previously published on the websites of IIgANN and RPS.
7. Process for database, electronic data transfer, data verification
All clinical and laboratory data will be anonymised at source, and collected on customised
Excel spreadsheets. Data will be verifies by double entry at each contributing centre. Data analysis will be undertaken by Stephan Troyanov under the consensus direction of the whole group.
8. Process for circulation of pathological material and scoring
The pathologists present at the Oxford meeting have all indicated their willingness to participate.
Circulation of s lides and biopsy reports will be coordinated by Ian Roberts [Oxford, UK].
Phase 1 [to be completed by the time of USCAP Meeting, February 2006]
40 biopsies will be circulated without clinical data to establish consistency of scoring. Pathologists will meet at USCAP to review cases with focus on scoring discrepancies
Phase 2 [to be completed by ASN November 2006]
300 cases, for which the clinical dataset is available will be reviewed and scored by pairs of pathologists, who will confer if necessary where there are discrepancies to agree a final score.
9. Future work
The group will communicate by e-mail. Pathologists will meet at USCAP 2006. The whole group will meet at ASN 2006 to assess progress and consolidate plans.
