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.

The impact of initial surgical management on outcome in young patients with differentiated thyroid cancer

BACKGROUND/PURPOSE

It is generally believed that differentiated thyroid cancer (DTC) in young patients has an excellent prognosis. This calls into question the need for more extensive surgical ablation of the thyroid gland with attendant risks of surgical complications. The purpose of this report was to investigate both the incidence of surgical morbidity and the impact of surgery on locoregional recurrence of disease.

METHODS

The authors reviewed the clinical course of patients under 22 years of age treated for DTC within Department of Defense hospitals since 1950. Data were available for determination of surgical morbidity in 126 and for outcome in 105.

RESULTS

The incidence of postoperative hypocalcemia was 17% and of recurrent laryngeal nerve injury 3%. Factors predictive of morbidity were (1) more extensive thyroid surgery (P = .023), and (2) the presence of gross tumor invasion (P = .022). The incidence of neck recurrence was analyzed among a cohort of 90 patients. A total of 19 (21%) patients had a local recurrence. The median time to recurrence was 24 months. The factor predictive of recurrence was the presence of gross invasion (P = .0001). A strong trend toward locoregional recurrence was found among patients with metastatic disease to more than five cervical nodes (P < .08). The primary operations on the thyroid and regional nodes were not significant predictors of neck recurrence. Among these 19 patients there have been no deaths, but 25% had persistent disease at a mean follow-up of 12.6 years.

CONCLUSIONS

The incidence of surgical morbidity does increase with more extensive surgery. Outcome is predicted primarily by the initial extent of disease.

Agenesis of the gallbladder. A cause of false-positive ultrasonography

Ultrasonography has evolved into a nonhazardous relatively inexpensive means of diagnosing biliary tract disease. It is considered to have a 95 per cent sensitivity for the diagnosis of cholelithiasis. Occasionally, a small contracted gallbladder associated with stones and chronic cholecystitis will be difficult to visualize with ultrasonography. Two patients with agenesis of the gallbladder were recently treated by the authors. Each patient had ultrasonographic evidence suggestive of a contracted gallbladder with stones. Both patients were explored and found to have absent gallbladders and normal operative cholangiograms. Agenesis of the gallbladder is a rare congenital anomaly with a reported incidence of from 0.01 to 0.04 per cent. Approximately 220 cases have been reported in the literature. Most of these are from necropsy studies. Many of these were newborns with more serious anomalies. One might project an increase in adult cases on the basis of increased usage of ultrasonography in patients with abdominal problems. At the present time, only operative findings including cholangiography can be considered as diagnostic of gallbladder agenesis. However, as more of these cases are reported, preoperative awareness of this entity will be increased.

Steroid metabolism by an oestrogen-dependent interstitial-cell tumour of a rat testis

Steroid metabolism by a unique, transplantable, oestrogen-induced, hormone-dependent interstitial-cell tumour of a rat testis was investigated. After incubation of the minced tumour in medium without substrate the presence of 3α-androstanediol, 3-epiandrosterone and androsterone was shown. There was inconclusive evidence for the presence of smaller amounts of 3β-androstanediol, and no evidence for testosterone. [14C]Pregnenolone substrate was shown to be metabolized after 2 h to androstenedione, androsterone and a small amount of testosterone. Epi- and dehydroepiandrosterone were probably formed from [14C]pregnenolone, but were incompletely characterized.