1. Age dependent type 1 diabetes pathogenesis
Ake Lernmark

2. From
Joerg Ermann &
C. Garrison Fathman
Nature Immunology
2, (2001)

3. Insulitis

5. Type 1 diabetes genes v
HLA DQ2, DQ8, or both, represents almost 90% of all
type 1 diabetes patients younger than 20 years of age.
The risk of DQ2/8 heterozygotes decreases with increasing age.
The protection of DQ6.2 is attenuated by increasing age and is lost at about 35 years of age. v v v
Class I - INS VNTR -short tandem repeats - increase the
risk by about 2-5 %. v
CTLA-4 - long AT-repeats at the 5’ end UTR - increase
the risk by about 2-3%.

6. ENVIRONMENTAL FACTORS
* MONOZYGOTIC TWINS 20-30% CONCORDANCE.
** ONLY 10-15% OF NEW PATIENTS HAVE A
PARENT OR SIBLING WITH THE DISEASE.
VIRUS: MUMPS,COXSACKIE, RUBELLA, ECHO,
ROTA, LJUNGAN AND OTHERS.
FOOD ITEMS: NITROSAMINES, MILK PROTEINS
GESTATIONAL INFECTIONS AND ABO
INCOMPATIBILITY

7. VIRUS AND TYPE 1 DIABETES
Coxsackie Human, mice (Yoon)
Rubella Human, hamster
Mumps Human
Cytomegalovirus Human
Rotavirus Human
CBV4 T cell activation (Vbeta analysis): T1DM=controls
(Varela-Calvino et al. 2001)
CBV4 T cell proliferation: T1DM > controls (Juhela et al 2000)
CBV4-specific T-cell epitopes: T1DM = controls
(Martilla et al. 2001)
No or little cross reactivity between molecular mimicry regions
(Several authors)

8. ABO and hyperbilirubinemia
Autoantibody Controls ABO immunization Hyperbilirubinemia
IA-2Ab 1,4% (4/288) 6,6% (10/151)* ,6% (5/311)
GAD65Ab 1,6% (5/320) 2,6% (4/151) ,3% (4/311)
ICA ,6% (2/320) 4,0% (6/151)** ,2% (13/311)***
Difference compared to controls: * p=0.007; ** p=0.015; *** p=0.003.
All samples are cord blood.

10. R R R R R GENETIC EFFECTS ON AGE-DEPENDENT ONSET AND
ISLET CELL ANTIBODIES IN TYPE 1 DIABETES. R
PATIENTS: INCIDENT, 0-34 YEARS OF AGE
n=971 R
CONTROLS: MATCHED FOR AGE AND GENDER
n=702 R
HLA, INS VNTR AND CTLA-4 R
GAD65A, IA-2A, IAA AND ICA
LOGISTIC REGRESSION TO MODEL THE NATURAL
LOGARITHM OF THE ODDS R

14. RISK FOR TYPE 1 DIABETES AS FUNCTION OF AGE, GENDER, HLA AND GAD65A.
THE ODDS TO DEVELOP TYPE 1 DIABETES:
A FEMALE WITH GAD65Ab HAS
3 TIMES THE RISK OF A MALE.
COMPARED TO A FIVE YEAR OLD WITH GAD65Ab BUT NO DQ2:
3 TIMES HIGHER RISK WITH ONE DQ2
8 TIMES HIGHER RISK WITH TWO DQ2
DQ2 DOES NOT AFFECT THE RISK FOR
A GAD65AB POSITIVE 34 YEAR OLD

18. RISK FOR TYPE 1 DIABETES AS FUNCTION OF AGE, GENDER, HLA, AND IA-2Ab.
THE ODDS FOR TYPE 1 DIABETES WITH IA-2Ab
AT 5 YEARS OF AGE IS 11 TIMES THAT AT
34 YEARS OF AGE.
THE ODDS FOR EACH ADDITIONAL DQ8:
1.5 TIMES FOR ONE DQ8
3.0 TIMES FOR TWO DQ8
THE ODDS OF EACH ADDITIONAL DQ2:
DECREASES
0.27 TIMES FOR ONE DQ2
0.6 TIMES FOR TWO DQ2

19. Insulin autoantibodies are associated with a
combination of HLA-DQ8 and INS VNTR.
Click for larger picture

20. RISK FOR TYPE 1 DIABETES AS FUNCTION OF AGE, GENDER, HLA, INS VNTR AND IAA.
THE ODDS FOR TYPE 1 DIABETES WITH IAA
AT 5 YEARS OF AGE IS 10 TIMES THAT AT
34 YEARS OF AGE.
THE ODDS FOR EACH ADDITIONAL DQ8:
1.4 TIMES FOR ONE DQ8
2.1 TIMES FOR TWO DQ8
THE ODDS OF EACH ADDITIONAL INS VNTR
CLASS I ALLELE:
1.5 TIMES FOR ONE CLASS I
2.2 TIMES FOR TWO CLASS I

21. SUMMARY, SO FAR……... * MULTIPLE ENVIRONMENTAL FACTORS.
*GESTATIONAL EFFECTS.
* HLA HAS THE MAJOR GENETIC EFFECT
- INS VNTR AND OTHER GENETIC FACTORS
CONTRIBUTE.
* AGE-DEPENDENT EFFECTS OF HLA AND ON
GAD65Ab
IAA - INS VNTR CONTRIBUTES
IA-2Ab
* USEFUL INFORMATION FOR PREDICTION?

22. COMBINATIONS OF ISLET CELL AUTO-ANTIBODIES PREDICT TYPE 1 DIABETES
Click for larger picture

23. WHAT ABOUT CHILDREN AND TEENAGERS?
* WASHINGTON PREDICTION STUDY:
> year olds were screened
Follow up 9 years.
All 15 children developing diabetes were predicted. No false negatives.
No false positives.
Hagopian et al. Diabetes Care 2002
* SCREENING NEWBORNS: HLA and antibodies
DIPP (Finland), TRIGR (international),
DAISY (Denver, CO), PANDA (Gainesville, FL),
ABIS (South East Sweden),
DiPiS (South Sweden)
MELBOURNE NEWBORN STUDY

24. TYPE 1 DIABETES IS A T-CELL MEDIATED DISEASE
* Poor antigen quality has hampered novel technologies to detect
T-cells reactive with GAD65, proinsulin (PI), and IA-2.
* The second T cell IDS workshop reported GAD65 (Diamyd Medical)
generated in insect cells that stimulate relevant clones and
does not inhibit third-party antigens.
* A PI preparation generated in bacteria was free of effects on
proliferation to third-party antigens and low in endotoxin.
* These preparations should be useful to develop robust and sensitive
assays of autoantigen-specific T cells that predict diseases.
* Peakman et al. Report of phase II of the Second International
Immunology of Diabetes Society Workshop for Standardization
of T-cell assays. Diabetes 50: , 2001.

25. GAD65Ab modulate GAD65 antigen presentation.
T-cell hybridomas
DRB1*0401 restricted
GAD65 peptide dependent
APC from DRB1*0401 subjects
IL-2 release response
GAD65Ab positive sera from new onset children at various end-point titers
Reijonen et al Diabetes 2001

26. IL-2 concentration(U/ml)
0,0
2,5
5,0
7,5
10,0
12,5
0,0
0,25
0,5
0,75
1,0
1,25
IL-2 concentration(U/ml)
GAD65 antibody index

27. ANTIBODY-MEDIATED POTENTIATION OF ANTIGEN-PRESENTATION.
GAD65Ab mediated potentiation of antigen presentation may explain:
Preservation of conformation dependent GAD65Ab before diagnosis.
Preservation of conformation dependent GAD65Ab after diagnosis when beta cells are gone.
Acceleration of beta cell destruction by recruiting new CD4 and CD8 T cells.

28. SUMMARY AND CONCLUSIONS
* HLA HAS THE MAJOR EFFECT - OTHER GENETIC FACTORS SUCH AS INS VNTR AND CTLA-4
CONTRIBUTE.
* MULTIPLE ENVIRONMENTAL FACTORS.
*GESTATIONAL EFFECTS.
*EARLY T CELL RESPONSES ARE KEY TO INITIATION
OF BETA CELL AUTOIMMUNITY.
* AGE-DEPENDENT EFFECTS OF HLA AND ON
GAD65Ab
IAA INS VNTR CONTRIBUTE
IA-2Ab.
* CHRONIC BETA-CELL AUTOIMMUNITY MAY BE MAINTAINED BY AUTOANTIBODY-FACILITATED T CELL RESPONSES.

29. Acknowledgement JINKO GRAHAM NORMAN BRESLOW CHRISTIANE HAMPE LUO DONG
HELENA REIJONEN
GERALD T NEPOM
SWEDISH DIABETES REGISTRIES FOR CHILDREN AND ADULTS
CHRISTIANE HAMPE
LUO DONG
TERRI DANIELS
LISA HAMMERLE
STEN-A. IVARSSON
CORRADO CILIO