The insulin gene region and susceptibility to insulin-dependent diabetes mellitus in four races; new insights from Afro-Caribbean race-specific haplotypes

Factors affecting the resolution of acute non-infectious anterior scleritis

BACKGROUND/AIMS

Tumor necrosis factor alpha (TNF-⍺) inhibitors are increasingly being used to treat scleritis, however, their efficacy has not been compared to older treatments. Additionally, few studies have assessed differences in the course of scleritis among different patient groups. We identify demographic factors, comorbidities and treatments associated with the resolution of acute scleritis.

METHODS

The records of patients with non-infectious anterior scleritis who presented between 1 January 2013 and 1 January 2018 were retrospectively reviewed.

RESULTS

A total of 141 patients (169 eyes) with anterior scleritis were identified. 92.9% had diffuse anterior scleritis, 5.0% had nodular anterior scleritis and 2.1% had necrotising scleritis. Topical corticosteroids were used in 66.7% of patients, systemic non-steroidal anti-inflammatory drugs (NSAIDs) in 48.9% and systemic corticosteroids in 37.6%. Non-corticosteroid immunomodulatory therapies were required in 37.6% of patients. In a Cox proportionate hazards model, factors positively associated with the resolution of an episode of scleritis included NSAID use (HR=2.145; 95% CI 1.200 to 3.832), Hispanic race (HR=2.991; 95% CI 1.115 to 7.341) and lupus erythematous (HR=6.175; 95% CI 1.774 to 21.489). Bilateral scleritis was negatively associated with resolution (HR=0.437; 95% CI 0.196 to 0.972). TNF-⍺ inhibitors (HR=3.346; 95% CI 1.277-8.763), NSAID use (HR=2.558; 95% CI 1.383 to 4.729), lupus erythematosus (HR=5.251; 95% CI 1.478 to 18.659) and Hispanic race (HR=3.198; 95% CI 1.022 to 10.005) were significantly positively associated with steroid sparing resolution.

CONCLUSION

Patient characteristics including a lupus diagnosis and Hispanic race were associated with faster times to symptom resolution and steroid sparing resolution, as were treatments including systemic NSAIDs and TNF-⍺ inhibitors. Due to limitations in the available data, this analysis did not account for disease severity. Future prospective studies will further elucidate the relationship between these factors and patient outcomes.

Race/ethnicity is an independent risk factor for autoimmune hepatitis among the San Francisco underserved

Although autoimmune hepatitis (AIH) is more common in women and affects people of all races/ethnicities, there is currently limited information regarding the relationship between race/ethnicity and AIH, especially in the context of underserved populations. We aim to evaluate the relationship between race/ethnicity and AIH and better characterize its clinical features among different racial groups. We conducted a 15-year retrospective analysis, from January 2002 to June 2017, of patients seen at Zuckerberg San Francisco General Hospital (ZSFG). Sixty-three AIH patients and 2049 non-AIH controls were eligible for the study. The main predictor of interest was race/ethnicity, and the main outcome of interest was AIH diagnosis; other secondary measures recorded include clinical features such as ALT, bilirubin, and biopsy fibrosis at presentation. In a multivariable model adjusting for age and sex, we found that black (OR 9.6, 95% CI 1.8-178), Latino (OR 25.0, 95% CI 5.3-448), and Asian/Pacific Islander (API) (OR 10.8, 95% CI 2.2-196) race/ethnicity were associated with increased odds of an AIH diagnosis compared to the white reference group. Among people of colour with AIH, there were no significant differences in baseline ALT (p = .45), total bilirubin at presentation (p = .06), fibrosis at presentation (p = .74), and hospitalization (p = .27). Race/ethnicity is an independent risk factor for AIH. The clinical features of AIH did not differ significantly among black, Latino, and API patients.

The association of variable number of tandem repeats of the insulin gene with susceptibility to type 1 diabetes among Korean subjects

BACKGROUND

There is ethnic variation in the variable number of tandem repeats of the insulin gene (INS VNTR), one of the susceptibility loci for developing type 1 diabetes (T1D). We evaluated the influence of the genotypes and subdivisions of INS VNTR on the development of T1D in Korean subjects.

METHODS

The study included 352 Korean patients, under the age of 18 years who were diagnosed as having T1D, and 356 control subjects. The insulin - 23HphI A/T single nucleotide polymorphism was used as a marker of class I and III alleles. Surrounding polymorphisms at nucleotide positions + 1127, + 1140, + 2331 and + 2336 were determined as subdivisions of INS VNTR.

RESULTS

Classes I/I, I/III and III/III were observed at frequencies of 95.8, 4.2 and 0% among all subjects, respectively. Class I/III genotype was significantly less frequent in patients with T1D than in controls (2.56 versus 5.90%; odds ratio 0.419; P = 0.039). In a subdivision analysis, the ID/ID genotype was decreased among patients (P = 0.017, adjusted P = 0.085) and the IC allele tended to increase. The frequency of the class I/III genotype was significantly lower among patients who were diagnosed when younger than 7 years of age than in controls (odds ratio 0.115; P = 0.011).

CONCLUSIONS

INS VNTR has predominance of class I over class III alleles and is associated with susceptibility to T1D in Koreans. In addition, INS VNTR shows distinctive susceptibility according to the age at the onset of T1D.

Genetic polymorphisms in susceptibility to Type 1 Diabetes

Type 1 Diabetes is a serious complex disease caused by several environmental and genetic factors. It is one of most common childhood diseases, requires life-long treatment, and is associated with increased mortality, mainly due to complications that occur later in life. More than three decades of genetic studies have identified several genetic disease variants and a longer list of putative associated genetic loci. These findings have greatly increased our understanding of the genetic background of T1D and have encouraged the development of genetic tools for mapping complex diseases. Here we review the wealth of data on T1D and discuss the major genetic polymorphisms involved in the disease. We place some putative genetic risk factors in perspective and look at those still to be detected.

The insulin gene in diabetes

Lack of insulin production or abnormalities affecting insulin secretion are key to the development of almost all forms of diabetes, including the common type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes and the more rare forms of maturity-onset diabetes of the young (MODY). Because insulin has such a central role in the pathogenesis of both forms of diabetes, the insulin gene (INS) has always been considered a candidate susceptibility gene. A number of studies have shown that the allelic variation and parent-of-origin effects affect the transmission and expression of the insulin gene in pancreatic beta-cells and extra-pancreatic tissues. These observations have led to the formulation of new hypotheses to explain the biological mechanisms by which functional differences in the expression of the insulin gene may contribute to diabetes susceptibility.

Genetic epidemiology of type 1 diabetes mellitus in Taiwan

Some environmental and genetic factors play important roles in etiopathogenesis of type 1 or insulin-dependent diabetes mellitus (IDDM). HLA genes, the IDDM1 locus located the human chromosome 6, were found to be associated with insulin-dependent diabetes mellitus. However, the incidence of IDDM varied greatly among various populations. To evaluate the pathogenetic factors contributing to the development of IDDM in Taiwan, HLA typing was performed in a group of IDDM unrelated individuals and IDDM pedigrees along with the normal controls from the northern Taiwan. DNA genotypes of class II HLA were done by polymerase-chain-reaction based oligotyping techniques. We confirmed that class II HLA genes were significantly associated with IDDM in Taiwan. To study detailed molecular structure of class II HLA molecules and disease association, we examined several amino acid residues on DQalpha and DQbeta chains and the molecular mechanisms to explain the heterozygotic effect of the DR3/DR4 and DR3/DR9 in the Chinese population. Linkage analysis in our pedigrees confirmed the association between HLA and IDDM in population association studies. Among the several class II alleles, a closer segregation of HLA-DQB1*0401 to the affected persons might suggest that HLA-DQB1*0401 itself or an allele closely linked to the DQB1 locus was the IDDM-predisposing allele in Taiwanese. For IDDM2 (INS) region, association with IDDM was not found due to that more than 90% of the population carried class I alleles. In our collection of IDDM, we found few cases (2.4%) carried mitochondrial DNA mutation. Our studies in Taiwanese confirm a multigenetic nature for IDDM.