The Intersection of COVID-19 and Autoimmunity: What is Our Current Understanding?

Viral infections have historically had a complex relationship with autoimmune diseases. For patients with preexisting autoimmune disorders, often complicated by immunosuppressive therapies, there are numerous potential effects of COVID-19, a disease of complex immunobiology, including the potential for an altered natural history of COVID-19 when infected. In addition, individuals without recognized autoimmune disease may be vulnerable to virally induced autoimmunity in the forms of autoantibody formation, as well as the development of clinical immune-mediated inflammatory diseases. Until quite recently in the pandemic, this relationship between COVID-19 and autoimmune diseases has been relatively underexplored; yet such investigation offers potential insights into immunopathogenesis as well as for the development of new immune-based therapeutics. Our review examines this relationship through exploration of a series of questions with relevance to both immunopathogenic mechanisms as well as some clinical implications.

Oribatid mite communities in the canopy of montane Abies amabilis and Tsuga heterophylla trees on Vancouver Island, British Columbia.

To study the oribatid mite community inhabiting microhabitats in the canopy of montane Abies amabilis [(Douglas ex D. Don) Lindl.] and Tsuga heterophylla [(Raf.) Sarg] tree species across five elevational sites, we collected 180 branch tips and 180 foliose/crustose lichen samples over three time periods. Thirty-three species of oribatid mites were identified from the study area. Mite species richness and abundance was significantly affected by microhabitat, and this association was independent of sampling time. At the microhabitat scale, distinct species assemblages were associated with lichen and branch tip habitats, and to a lesser degree, tree species. Conifer specificity was most apparent in the closely related species of Jugatala, where Jugatala tuberosa Ewing was only found on branch tips from A. amabilis and Jugatala sp. was primarily found on branch tips from T. heterophylla. Microhabitat specificity was most pronounced in Dendrozetes sp. where most individuals were found on branch tips and Anachiperia geminus Lindo et al. that occurred primarily on lichens. Principal components analysis of oribatid mite community composition further showed a high degree of association with microhabitat and tree species. Habitat profiles are difficult to discern for many species because tree, microhabitat, and elevation preferences confound distribution patterns. Given the significant tree-microhabitat associations in species composition in this montane canopy study, we suggest that sampling multiple microhabitats across elevations to look for patterns in community structure offers opportunities to explicitly test organizing principles in community ecology.

Sexual behavioral changes in Alzheimer disease.

The frequency and correlates of sexual behavioral changes in Alzheimer disease (AD) were assessed in two studies. In the first study, we reviewed the medical records of 135 consecutive community-living patients who fit the criteria of the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer Disease and Related Disorders Association for probable or possible AD, and we asked spouses to complete a questionnaire that included two questions about sexual activity. Indifference to sexual activity was reported by 70% of the spouses, and sexual behavioral modifications were reported by 50%. No correlation was found between sexual changes and the general characteristics of the patients, the severity of the disease, or depressive symptomatology. Sexual changes were correlated to the severity of behavioral and mood disorders, mainly to a reduction of activity and emotional deficit. Seventy-seven of the patients had a second examination after an interval of 18.9 +/- 9.9 months. The links between sexual changes and the other variables were similar to those found by the first examination. In the second study, a questionnaire was sent by mail to the spouses of 100 patients. No relationship was found between sexual changes and the severity of cognitive deficits, previous sexual agreement, age, or gender. Sexual changes were considered a factor of maladjustment for the couple by 46% of the spouses.

Determination of the Transmittance Uniformity of Optical Filter Standard Reference Materials.

An instrument based on a scientific grade charge-coupled device (CCD) camera system is performance-qualified to evaluate the transmittance homogeneity of solid optical filter standard reference materials. Measurement results are presented for the new instrument, and compared, where appropriate, with an older, scanning instrument, for a variety of filters spanning transmittances down to 0.01. The new instrument is found to give comparable results with the older instrument, with reduced random uncertainty and improved information content.