should all children with type 1 diabetes be screened for celiac
TRANSCRIPT
Should all children with type 1 diabetes be screened for celiac disease?
Edwin Liu, [email protected]
Screening-identified patient
• 15 yo with type 1 diabetes (T1DM) diagnosed at age 6.
• Recently screened for CD tTG+• His mother wants to pursue biopsy, wants
to prevent future potential complications.• Patient unsure, but will do whatever his
doctors recommend.• Asymptomatic, good growth, normal
nutritional labs, normal DEXA.
Biopsy showed Marsh 3 lesions, diagnosed with CD
• Started the gluten-free diet (GFD).• tTG autoantibodies resolve.• Follow-up over the next 2 years, remains
adherent to the diet but feels no different.• He wants to be a good patient, but admits
that the diet is difficult.
So, what is the rationale for screening and treating CD in this patient? Are we doing him
any favors?
Screening Recommendations
AGA ADA
NASPGHAN ESPGHAN
Screening Recommendations
AGA
It is the position of the American Gastroenterological Association (AGA) Institute that testing for celiac disease (CD) should be considered in symptomatic individuals who are at particularly high risk.
Screening Recommendations
ADAPatients with type 1 diabetes (T1DM) should be screened for celiac disease.
Positive antibody levels should be confirmed.
Referral to a gastroenterologist for consultation.
Screening Recommendations
NASPGHAN
It is also recommended to test asymptomatic children who belong to specific groups at risk…type 1 diabetes
Screening Recommendations
ESPGHAN
Testing for CD should be offered to asymptomatic children and adolescents with an increased risk for CD such as T1DM
Screening T1DM for CD
• Primary reason for screening is because having T1DM is a risk factor for developing CD– The same reasons for screening any other
group at risk for CD should apply to screening in T1DM
– But are there any specific benefits (or potential harm) to screening and treating for CD in T1DM?
Considerations for generalized screening of CD in T1DM
• What is the risk of developing CD with T1DM?• Will all individuals with asymptomatic CD
develop long-term complications?– If not, should we treat every patient with
asymptomatic CD to prevent complications in just a subset of patients?
• What are the potential benefits and potential harmful effects of gluten-free diet in T1DM?
More questions than answers!
CD and T1DM share DR3-DQ2 and DR4-DQ8 as part of their risk
The major haplotype, DR3-DQ2 is present in:• 90% of patients with CD• 55% of patients with T1DM• 20-25% of general population of European
ancestry
What is the frequency of Celiac Disease in T1DM?
T1DM 4-12%
T1DM (DQ2/DQ2) 33%Bao, J Autoimmunity 1999
The co-occurrence of both CD and T1DM are mainly dependent on shared HLA
An example of how we can learn from the study of other autoimmune diseases:
Natural History Studies in Type 1 Diabetes
Observational, prospective, birth cohort studies to look at the natural history of islet autoimmunity, and to identify environmental triggers
• Germany – BABYDIAB
• Finland – DIPP (Type 1 Diabetes Prediction and Prevention Project)
• Denver – DAISY (Diabetes Autoimmune Study of the Young)
• Multinational – TEDDY (The Environmental Determinants of Diabetes in the Young)
Given the shared HLA risks, subjects are also monitored for CD in these studies!
DR3-DQ2/DR4-DQ8
DR4-DQ8/DR4-DQ8
DQ8
DQ2
BABYDIAB studyDR3-DQ2/DR4-DQ8 is the highest risk for
T1DM, followed by DR4-DQ8/DR4-DQ8
Achenbach P et al. Diabetes 2005;54:S25-S31
DQ8/DQ8
DQ2/DQ8
% T
ype
1 D
iabe
tes
auto
antib
odie
s
HLA group % incidenceat 10 years
DQ2/DQ2 17.9%DQ2/DQ8 13.7%
DQ2/X 13.8%DQ8/DQ8 7.3%
DQ8/X 3.2%
Cel
iac
Aut
oim
mun
ity (%
)
Age (years)
DQ2/DQ2DQ2/DQ8
DQ2/X
DQ8/XDQ8/DQ8
DAISY StudyDR3-DQ2/DR3-DQ2 is the highest risk
for CD, followed by DR3-DQ2
Natural history of untreated CD?• Burden of untreated symptomatic CD is well
described• What about untreated subclinical CD in adults?
– 4x increased mortality in young adults– Limited morbidity and no increase in mortality in older
individuals• Lower ferritin levels• Reduced bone density• Lower BMI and cholesterol (favorable)
• Undiagnosed CD can confer benefits and liabilities to older individuals.
Godfrey JD, Gastro 2011
Rubio-Tapia A, Gastro 2009More studies needed to determine the
natural history of screening-identified CD
Does GFD prevent autoimmunity?• Rationale
– Anti-tTG develop in NOD mice• Sblattero D, J Immunol 2005
– Prevention of T1DM in NOD mice with various dietary interventions
– Early dietary factors (cereal exposure) affects risk of T1DM in humans
• Zeigler A, JAMA 2003• Norris J, JAMA 2003
No good clinical studies to indicate that GFD will prevent T1DM
Will untreated celiac disease lead to development of other autoimmunity?
1. Ventura A, Gastroenterology 1999
2. Ventura A, J Pediatr 2000
3. Cosne J, Clin Gastroenter Hepatol 2008
1. Sategna Guidetti C, Gut 2001
2. Ansaldi N, J Pediatr Gastroenterol Nutr 2003
3. Viljamaa M, Scand J Gastroenterol 2005
4. Meloni A, J Pediatr 2009
No Yes
Data is mixed about autoimmune thyroiditis and other autoimmunity in association with duration
of gluten exposure
Determine the benefits of screening for tTG+ in children with T1DM
Baseline characteristics• 79 children with T1DM and tTG+, and 56 T1DM and tTG-
children followed for 2 years• Body composition, bone health and nutritional markers
evaluated at baseline, 1 year and 2 years.
BASELINE:• tTG+ children had altered body composition but not
reduced bone mineral density (BMD) compared to tTG-.• tTG+ children self-selected for GFD (43) or regular diet
(36)• No difference in symptoms
2-year findings• tTG+ children maintained (at baseline and at 2 years)
consistently lower scores for weight and BMI and increased bone turnover than tTG- subjects.
• No difference in HbA1c levels and frequency of hypoglycemic episodes
• No significant differences in tTG+ patients following a GFD vs regular diet, including symptoms.
• Half of children reportedly following GFD have remained persistently tTG+
• Children with persistent high tTG levels (>10x) had also reduced BMD, vitamin D, and ferritin levels
Limitations of the ROSE study
• Not randomized• Some crossover between GFD and regular diet
– reflects the changing attitudes of parents regarding GFD in tTG+ children
• Two-year follow-up may be too short to find differences in bone density/growth
• Smaller numbers were not powered to determine an absence of a difference between tTG+ and tTG- groups.
Summary• No differences in metabolic control in tTG+
children vs tTG- children
• Limited adverse outcomes in tTG+ children who remained untreated over 2 years compared to tTG- children
• Persistence of tTG at high levels should be a reason for concern, regardless of reported dietary compliance.
• There may not be a rush to treat for CD in patients with T1DM
What is the evidence that celiac disease affects individuals with type 1 diabetes?
# CD and T1DM
Condition at presentation Findings
*Simmons 2011 79Screening-identified children
Higher persistent tTG levels had lower bone mineral density z-scores, ferritin, and vitamin D levels after 2 years
Freemark 2008 30 Asymptomatic children
High tTG levels correlated with lower weight and BMD
Leeds 2011 12Newly
diagnosed adults
Worse glycemic control, higher prevalence of retinopathy and nephropathy at diagnosis
Pitocco 2011 30 Adults, existing CD
T1DM+CD show more severe subclinical atherosclerosis compared to those presenting T1DM or CD only
All studies compared type 1 diabetics with CD vs without CD*indicates prospective evaluation
What is the effect of GFD in T1DM?# children Duration of
follow-up Benefit of GFD
*Husby 2006 33 2 years Improved SDS height & weight, hemoglobin, ferritin
*Dunger 2002 11 2 years Improved BMI and HbA1C
Stern 2005 9 1-6 years Improved SDS height, HbA1C, anemia
Catto-Smith 2004 21 1 year Improved growth, glucose control
Abid 2011 23 1 year Improves symptoms and hypogycemia, increased insulin requirements.
Protheroe 2009 22 1 year Resolution of symptoms and improved nutritional status with GFD
Rami 2005 98 > 1 year Decreased weight gain, but no effect on metabolic control
Goh 2010 29 1 year Asymptomatic children, no significant changes in BMI, height Z-score or metabolic control
Chan 1999 20 ? No benefit, no difference from type 1 diabetic controls
All studies compared type 1 diabetics with CD vs without CD*indicates prospective evaluation
My conclusions from these studies of CD and T1DM
• Some differences in outcomes may be related to phenotype of CD – some groups more symptomatic than others
• In asymptomatic cases, the benefit of GFD appears to be mainly limited to growth and bone health
• Trend towards improved metabolic control (HgbA1c, hypoglycemic episodes) and increased insulin requirements
• 2 years prospective follow-up likely not sufficient to detect potential long-term complications
How does Celiac Disease affect Quality of Life in T1DM?
• The “double” diagnosis of CD has minimal impact on quality of life in children with T1DM– however, parents of CD + T1DM children did express greater
concern about their child's social functioning.
• Most celiac patients found it challenging to adhere to a GFD– Challenging diet was associated with reductions in patient
wellbeing and increased psychological distress
Sud S, Pediatr Diabetes 2012Barratt J Gastrointestin Liver Dis 2011
Screening for CD in T1DM
If symptomatic CD, then there is a clear benefit from GFD
Many screening-identified children do not have symptoms
Possible increase in mortality Prevention of morbidity and mortality is not known
Most patients with apparently silent CD were not completely asymptomatic
In asymptomatic cases the benefit appears to be limited to growth and bone mineralization
Increased risk of hypoglycemia, higher HbA1c, impaired growth, bone mineralization and possibly atherosclerosis
May have a significant impact on quality of life
Treatment is readily available Poor adherence to GFD (only about 50%).
FOR AGAINST
What evidence is lacking?• *No evidence that celiac autoimmunity predisposes to anti-islet
autoimmunity
• *No evidence that GFD reduces risk of anti-islet autoimmunity
• No compelling long-term prospective evidence to date to show
that asymptomatic children have significant long-term
consequences
• No strong long-term prospective controlled studies to support
GFD in type 1 diabetes (data on metabolic control is growing,
but not unanimously positive)
*negative studies
Recommendations for CD in T1DM• Should they be screened?
– High incidence – yes– annually, or if symptoms develop
• Should they be treated?– Reasons FOR and AGAINST treatment.– If symptomatic – no debate– If asymptomatic – look for pre-existing complications. If present,
then treat.– Otherwise, recommend thoughtful discussions with
patients/families. There may not be a rush to diagnose and treat!
– Bias towards being more conservative and recommend treatment in children – (they need to grow and develop, current data is not definitive)
Larger controlled, randomized prospective studies needed to determine natural history.
One final thought: Should children with CD be screened for T1DM?
• No recommendations at present for screening with islet autoantibodies in a patient with CD
• Low risk to develop diabetes:– HR 2.4 (95%CI 1.9-3.0) vs matched controls
followed to age 20 years
D’Annunzio G, Diabetes Care 2009
Ludvigsson Diabetes Care 2006
HLA genotypes in T1DM are more permissive for the development of CD, but not vice versa
HLA genotype frequencies for Denver general population
Vast majority of CD will have one of these
genotypes
HLADistribution
(%)DQ2/DQ2 1.1DQ2/DQ8 2.3
DQ2/X 17.1DQ8/DQ8 2.2
DQ8/X 17.3X/X 60.0
Highest risk genotypes for
T1DM
Could we adopt a personalized screening strategy for T1DM in celiac patients?
The Environmental Determinants of Diabetes in the Young
Age at developing tTG autoantibodies (Months)
Kap
lan-
Mei
er e
stim
ates
0 12 24 36 48 60 72 84
0.5
0.6
0.7
0.8
0.9
1.0
tTG autoantibodies
DR3-DQ2/DR3-DQ2 DR3-DQ2/DR4-DQ8DR4-DQ8/DR4-DQ8DR4-DQ8/DR8
Log-rank test p-value<0.0001
DR4-DQ8/DR8DR4-DQ8/DR4-DQ8DR3-DQ2/DR4-DQ8DR3-DQ2/DR3-DQ2Number of subjects at risk
901999
2052988
647702
1347595
362413789345
205237381151
DQ2/DQ2
DQ8
DQ8/DQ8
DQ2/DQ8
% w
ithou
t tTG
aut
oant
ibod
ies
Age at developing tTG autoantibodies (months)
Time to persistent tTG by HLA
TEDDY StudyDQ2/DQ2 is the highest risk for CD,
followed by DQ2/X