The question of the B-cell mass of non-diabetic autoantibody-positive (Ab+) subjects is crucial to understand both common forms of type 1 diabetes and latent autoimmune diabetes (LADA). It is well established that the presence of GAD Abs is not sufficient to predict diabetes or insulin dependency. Knowing the B cell mass of Ab+ donors could be crucial to decipher the history of diabetes between the initial lesion, marked by the appearance of Abs, and the onset of diabetes. To this aim, we propose to use the insulin-stained virtual slides of the nPOD project to quantify the B cell mass of Ab+ subjects. We will first test whether the insulin-stained virtual slides of the nPOD database can be used for this analysis. To this end, we will compare the B cell mass, islet size distribution and B cell distribution throughout the pancreas in control donors of the nPOD database with published data of the literature. We will then compare the Ab+ subjects to control donors and patients with recent-onset, i. e. <3 years T1D.
