Cutting Edge: A Critical Role of Lesional T Follicular Helper Cells in the Pathogenesis of IgG4-Related Disease.

IgG4-related disease (IgG4-RD) is a newly recognized systemic chronic fibroinflammatory disease. However, the pathogenesis of IgG4-RD remains unknown. To determine the pathophysiologic features of IgG4-RD, we examined T follicular helper (Tfh) cells in lesions and blood from patients with IgG4-RD. Patients with IgG4-related dacryoadenitis and sialadenitis (IgG4-DS) showed increased infiltration of Tfh cells highly expressing programmed death 1 and ICOS in submandibular glands. Tfh cells from IgG4-DS submandibular glands had higher expression of B cell lymphoma 6 and a greater capacity to help B cells produce IgG4 than did tonsillar Tfh cells. We also found that the percentage of programmed death 1hi circulating Tfh cells in IgG4-DS patients was higher than that in healthy volunteers and was well correlated with clinical parameters. Our findings indicate that anomalous Tfh cells in tissue lesions of IgG4-RD have features distinct from those in lymphoid counterparts or blood and potentially regulate local IgG4 production in IgG4-RD.

High frequency of Bob1lo T follicular helper cells in florid reactive follicular hyperplasia.

Florid reactive follicular hyperplasia (FRFH), which is characterized by large germinal centers (GCs) within normal lymphoid follicles, is often observed in benign lesions of lymph nodes and other tissues. Because of the histologic similarity of FRFH to tumorous lesions such as follicular lymphoma, careful pathological examination is required to evaluate such lesions; however, little is known about the mechanism underlying the development of FRFH. In this study, we investigated T follicular helper (Tfh) cells in hyperplastic tonsils of patients with obstructive sleep apnea syndrome (OSA), which frequently exhibits typical FRFH. When we analyzed tonsils of OSA and recurrent tonsillitis (RT) as a control, tonsils of OSA were found to harbor Tfh cells with a nearly 3-fold higher ratio in total CD4+ T cells than that in tonsils of RT. Further analysis showed that, in comparison to Tfh cells of RT tonsils, Tfh cells of OSA tonsils were relatively tolerant to CD3-mediated activation-induced cell death (AICD) and also expressed lower levels of a Bob1 transcription coactivator and IL-4, which fosters the development of GC-B cells. Given that Bob1 controls the proliferative activity in response to CD3 stimulation and has been suggested to have a role in the production of IL-4 in Tfh cells, the unique structure of FRFH is possibly associated with the function of Bob1lo Tfh cells.

Influence of Age on Caloric Response.

In an aging society, the number of patients suffering from vertigo and dizziness is increasing. Vertigo is mostly thought to occur owing to otorhinolaryngologic disease. In contrast, it is difficult to diagnose dizziness, because of its varied causes, and we believe that the number of elderly patients suffering from dizziness is increasing. Here, we evaluated the relationship between canal paralysis and symptoms at the first medical examination and age-related changes in caloric response, and obtained the following 3 main findings: (a) 41.3% of the patients with canal paralysis complained of dizziness at the first medical examination, with an increased tendency in patients aged >70 years; (b) the slow-phase eye velocity (SPEV) of patients aged >70 years was lower than that of patients aged ≤69 years, and the SPEV of patients complaining of vertigo was higher than that of patients who complained of dizziness during a caloric test, and (c) the percentage of patients complaining of dizziness and those not complaining of symptoms during a caloric test increased with age. In conclusion, patients with canal paralysis tend to complain of dizziness at the first medical examination, and the percentage of patients without vertigo during a caloric test increased with age.

Diagnosis and Treatment of Obstructive Sleep Apnea Syndrome in Children.

Sleep is important for children pertaining to their physical and mental growth. Obstructive sleep apnea syndrome (OSAS) in children has been shown to have different effects as compared to OSAS in adults, including deficits in cognition and neuropsychological functions, hyperactivity, ADHD, behavior problems, aggressive behavior, learning problems and nocturnal enuresis. Hypertrophy of the adenoids and tonsils is a major cause of OSAS in children; therefore, adenotonsillectomy may decrease the effects of OSAS pertaining to physical and mental growth. It is important to accurately diagnose and appropriately treat OSAS in children to prevent OSAS in their adulthood.

Cochlear Implantation in Children with Cochlear Malformation.

Cochlear implantation (CI) has proven to be an effective treatment for severe bilateral sensorineural hearing loss (SNHL). Inner ear malformation is a rare anomaly and occurs in approximately 20% of cases with congenital SNHL. In cases with cochlear malformation, CI can be successfully performed in nearly all patients, the exceptions being those with complete labyrinthine and cochlear aplasia. It is important to evaluate the severity of inner ear deformity and other associated anomalies during the preimplantation radiological assessment in order to identify any complication that may potentially occur during the surgery and subsequent patient management.