Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Improvements in patient-reported outcomes in patients with psoriasis receiving etanercept plus topical therapies: results from REFINE

Background

The REFINE study examined the efficacy and safety of adding topical corticosteroid therapy to etanercept when stepping down from the initial dose of etanercept to the maintenance dose. Clinical responses were shown to be similar in patients who remained on etanercept 50 mg twice weekly (BIW) and those who received etanercept 50 mg once weekly (QW) plus topical therapies through week 24.

Objective

The purpose of this analysis was to evaluate the effect of treatment on health‐related quality of life (HRQoL) for patients in REFINE.

Methods

All patients received etanercept 50 mg BIW for 12 weeks and were then randomized to etanercept 50 mg BIW or etanercept 50 mg QW plus topical corticosteroid as required to clear through week 24. HRQoL measures included the Dermatology Life Quality Index (DLQI), Treatment Satisfaction Questionnaire for Medication (TSQM) and the Economic Implications of Psoriasis Patient Questionnaire. No comparative testing was performed for this descriptive analysis. Missing data were imputed using the last observation carried forward.

Results

For 287 randomized patients (144 etanercept; 143 etanercept plus topical), the mean change [standard deviation (SD)] in DLQI from baseline to week 24 was 10.7 (7.8) for etanercept and 9.9 (6.9) for etanercept plus topical. Mean change (SD) in TSQM effectiveness, convenience, side‐effects and global satisfaction was 27.1 (36.1), 14.8 (25.9), −0.7 (22.0) and 26.7 (32.5) for the etanercept arm and 32.5 (40.3), 18.5 (29.0), 1.3 (19.4) and 28.4 (35.9) for etanercept plus topical. Economic implications, including healthcare visits, employment status, work productivity, ability to perform daily activities and out‐of‐pocket expenses were similar between treatment arms.

Conclusion

At week 24 of REFINE, measures of HRQoL were numerically similar in patients who stayed on etanercept 50 mg BIW and patients who received etanercept 50 mg QW plus topical therapies.

A Randomized, blinded assessor study to Evaluate the efFIcacy and safety of etanercept 50 mg once weekly plus as Needed topical agent vs. Etanercept 50 mg twice weekly in patients with moderate to severe plaque psoriasis (REFINE)

BACKGROUND

Topical corticosteroids are used with systemic therapies for treatment of plaque psoriasis, but data from randomized clinical trials to document efficacy of combination therapy are lacking.

OBJECTIVE

To evaluate efficacy and safety of adding topical corticosteroid therapy from the time that etanercept dosage is reduced from initial label dose [50 mg twice weekly (BIW)] to maintenance dose [50 mg once weekly (QW)].

METHODS

In this phase 3b, multicentre, randomized, open-label study, patients with moderate-to-severe plaque psoriasis received etanercept 50 mg BIW for 12 weeks, and then were randomized to etanercept 50 mg BIW or 50 mg QW plus topical agent as needed to achieve static physician global assessment (sPGA) status of clear for 12 weeks. Endpoints included percentage change in Psoriasis Area and Severity Index (PASI) score from week 12 to week 24 (primary endpoint); proportion of patients achieving 50% improvement in (PASI 50), PASI 75 and PASI 90; patients achieving sPGA of clear/almost clear; and change in affected body surface area (BSA).

RESULTS

Mean difference [95% confidence interval (CI)] between etanercept arm (n = 140) and etanercept plus topical arm (n = 142) in change in PASI score from week 12 to week 24 was 16.2% (-3.5%, 35.8%). PASI response rates were similar between groups. Percentage (95% CI) of patients achieving sPGA status of clear/almost clear was 40.6% (32.5%, 48.6%) and 45.8% (37.6%, 54.0%) at week 12 for patients in etanercept and etanercept plus topical arms, respectively, and 53.5% (45.3%, 61.7%) and 45.4% (37.2%, 53.6%) at week 24. Difference (95% CI) between groups in change in affected BSA from week 12 to week 24 was 4.9% (-23.4%, 33.2%).

CONCLUSION

Patients who received etanercept 50 mg QW at week 12 plus as-needed topical therapy and those who stayed on etanercept 50 mg BIW maintained clinical response through week 24 with no notable differences in PASI responses.

A study of the safety and efficacy of calcipotriol and betamethasone dipropionate scalp formulation in the long-term management of scalp psoriasis

BACKGROUND

Effective and safe products are needed for long-term management of scalp psoriasis. This study investigated the long-term safety and efficacy of a two-compound formulation (calcipotriol 50 microg/g plus betamethasone dipropionate 0.5 mg/g) for scalp psoriasis.

METHODS

In this 52-week, international, double-blind study, 869 patients with moderate-to-severe scalp psoriasis were randomized to either a two-compound scalp formulation (n = 429) or calcipotriol (n = 440).

RESULTS

Adverse drug reactions were less frequent in the two-compound group compared with the calcipotriol group (17.2 vs. 29.5%; p < 0.001). Incidences of adverse events possibly associated with long-term corticosteroid use were low in both the two-compound (2.6%) and the calcipotriol (3.0%) groups. Disease was satisfactorily controlled in 92.3% of visits in the two-compound group versus 80.0% in the calcipotriol group (p < 0.001).

CONCLUSION

The two-compound scalp formulation demonstrated a high level of safety and efficacy in long-term management of scalp psoriasis.

A long-term follow-up study of asymptomatic hepatitis B surface antigen-positive carriers in Montreal

BACKGROUND/AIMS

Prospective studies from the Far East and Alaska have shown an increased mortality from cirrhosis and/or hepatocellular carcinoma in asymptomatic hepatitis B virus (HBV) carriers. The magnitude of this risk in apparently healthy North American carriers remains undefined.

METHODS

The outcomes of 317 asymptomatic hepatitis B surface antigen-positive carriers from the Montreal area were examined after 16 years of follow-up. A majority of carriers were of French Canadian origin, were positive for antibody to hepatitis B e antigen, and had normal serum transaminase levels; institutionalization in orphanages as infants or children was the most important epidemiological risk factor, suggesting horizontal transmission of HBV during childhood.

RESULTS

At follow-up, mean age was 46 +/- 8 years; 3 carriers had died of HBV-related cirrhosis, 1 of alcoholic cirrhosis, and 9 of causes unrelated to liver disease. No carrier died of hepatocellular carcinoma; had the risk of hepatocellular carcinoma been similar to that reported from the Far East and Alaska, 17 cases of hepatocellular carcinoma-related deaths would have been expected. During follow-up, the annual negativation rate for hepatitis B surface antigen was 0.7%.

CONCLUSIONS

In asymptomatic HBV carriers from Montreal, a majority are "healthy" carriers and remain asymptomatic after 16 years of follow-up and the risk of death from HBV-related cirrhosis and/or hepatocellular carcinoma is low.

Vitamin D-sensitive and quinacrine-sensitive zinc transport in human intestinal cell line Caco-2

We studied the mechanism of transepithelial zinc (Zn) transport using monolayers of Caco-2 cells grown on permeable filter supports. 65Zn transport could be fitted to a modified Michaelis-Menten equation, which includes a nonsaturable [linear diffusion constant of nonsaturable component (Kd) = 0.08%.cm-2.90 min-1] and a saturable component [upper well Zn concentration at half Jmax (Kt) = 226 microM and maximal rate of saturable Zn transport (Jmax) = 1.06 nmol.cm-2.90 min-1]. Caco-2 cells contained metal-inducible metallothionein (MT) protein and mRNA as well as mRNA for cysteine-rich intestinal protein (CRIP). Cells pretreated with 10 nM 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] for 3 days transported more Zn (159%) than controls (0.48 +/- 0.02 nmol.cm-2.90 min-1) when each was incubated with 100 microM Zn for 90 min. This effect was significant after 24 h of 1 alpha,25-(OH)2D3 pretreatment and continued to increase up to 72 h, with concomitant increases in MT mRNA levels being observed (4-fold by 24 h, 10-fold by 72 h). MT protein levels were only modestly elevated by 72 h 1 alpha,25(OH)2D3 treatment (from 0.32 +/- 0.04 to 0.45 +/- 0.03 nmol MT/mg protein). CRIP mRNA levels were reduced by 1 alpha,25(OH)2D3 treatment. The lysosome-disrupting agent quinacrine (0.5 mM) inhibited basal Zn transport by 68%, suggesting the possible presence of a lysosome-mediated component for transepithelial Zn transport in Caco-2 cells. 1 alpha,25(OH)2D3-stimulated Zn transport was not affected by quinacrine, suggesting that 1 alpha,25(OH)2D3-induced Zn transport is distinct from the putative lysosome-mediated Zn transport pathway.