Anti-Plexin-D1 Seropositive Small Fiber Neuropathy: Clinical Phenotype, Demographics, and Literature Review.

OBJECTIVES: Small fiber neuropathy (SFN) is a subtype of painful neuropathies defined by dysfunction of the Aδ and unmyelinated C fibers. It presents with both neuropathic pain and dysautonomia symptoms, posing a significant diagnostic and therapeutic challenge. To address this challenge, research has been conducted to identify autoantibodies and define their association with phenotypes. METHODS: Eleven cases of anti-plexin-D1 seropositive SFN were reviewed, along with relevant literature, in attempt to better define anti-plexin-D1 SFN demographics, symptoms, associated medical conditions, and therapeutics. RESULTS: Anti-plexin-D1 SFN typically presents in female patients, with neuropathic pain, normal skin biopsy findings, and normal nerve conduction studies. Anti-plexin-D1 shows an association with concurrent chronic pain, with almost half of the patients undergoing an interventional procedure. CONCLUSIONS: Anti-plexin-D1 represents a unique subgroup of SFN, defined by distinct demographics, phenotype, biopsy findings, and therapeutic management.

The evolution and genomic basis of beetle diversity.

The order Coleoptera (beetles) is arguably the most speciose group of animals, but the evolutionary history of beetles, including the impacts of plant feeding (herbivory) on beetle diversification, remain poorly understood. We inferred the phylogeny of beetles using 4,818 genes for 146 species, estimated timing and rates of beetle diversification using 89 genes for 521 species representing all major lineages and traced the evolution of beetle genes enabling symbiont-independent digestion of lignocellulose using 154 genomes or transcriptomes. Phylogenomic analyses of these uniquely comprehensive datasets resolved previously controversial beetle relationships, dated the origin of Coleoptera to the Carboniferous, and supported the codiversification of beetles and angiosperms. Moreover, plant cell wall-degrading enzymes (PCWDEs) obtained from bacteria and fungi via horizontal gene transfers may have been key to the Mesozoic diversification of herbivorous beetles-remarkably, both major independent origins of specialized herbivory in beetles coincide with the first appearances of an arsenal of PCWDEs encoded in their genomes. Furthermore, corresponding (Jurassic) diversification rate increases suggest that these novel genes triggered adaptive radiations that resulted in nearly half of all living beetle species. We propose that PCWDEs enabled efficient digestion of plant tissues, including lignocellulose in cell walls, facilitating the evolution of uniquely specialized plant-feeding habits, such as leaf mining and stem and wood boring. Beetle diversity thus appears to have resulted from multiple factors, including low extinction rates over a long evolutionary history, codiversification with angiosperms, and adaptive radiations of specialized herbivorous beetles following convergent horizontal transfers of microbial genes encoding PCWDEs.