A case of Schnitzler syndrome with unusual immunoglobulin A gammopathy exacerbated by COVID-19 infection.

Schnitzler syndrome (SchS) is a rare autoinflammatory disease characterized by chronic urticarial rash and monoclonal immunoglobulin M (IgM) or IgG gammopathy. Viruses, including COVID-19, activate the innate immune system, therefore SchS, in which the innate immune system is improperly activated, is hypothesized to be exacerbated by viral infection. However, there were no reported SchS cases exacerbated by any viral infection. Here, we report a SchS case with an unusual IgA gammopathy manifested and exacerbated by COVID-19 infection. This report advocates the need for recognizing unusual cases of SchS with monoclonal IgA, and following up on paraprotein like IgA even when it is initially undetectable in cases with SchS symptoms. We also hypothesize that existing autoinflammatory diseases may be exacerbated by COVID-19 infection in the case of a combination of these diseases.

Effect of prolactin-induced protein on human skin: new insight into the digestive action of this aspartic peptidase on the stratum corneum and its induction of keratinocyte proliferation.

Human prolactin-induced protein (PIP) is a major protein found in exocrine fluids such as saliva and sweat. Intriguingly, PIP possesses residues (human PIP (hPIP): PIP (29-63)) that display similarity to the aspartic peptidase candidapepsin. Here, we aimed to determine the effect of PIP as a protease on normal skin structure. Using an adhesive tape-stripping technique, we applied hPIP peptide on the corneocytes of normal-appearing facial skin from infants with eczema and healthy infants and then analyzed the morphological structure of corneocytes with Nile Red fluorescence. We also repeatedly applied the hPIP peptide onto the surface of a three-dimensional (3-D) human skin model and then analyzed any changes to the stratum corneum and epidermis using light microscopy and scanning electron microscopy. In both infant groups, a decrease in hydrophobic lipids from the cornified envelope was observed after treatment with hPIP. The peptide hPIP appeared to digest the fine structure of the stratum corneum and induce a proliferation of epidermal keratinocytes within the 3-D human skin model. Our results suggest that aspartic peptidase of PIP found in sweat or saliva deteriorates the skin barrier in a de novo manner, which potentially leads directly to the proliferation of epidermal keratinocytes without any external antigenic factors.

Cancer deaths in a cohort of Japanese barbers in Aichi Prefecture.

Barbers have frequent occasion to come in contact with hair and beauty products that contain many chemical substances, which could have harmful effects on health. Subjects were barbers belonging to the Barbers' Union of Aichi Prefecture who responded to a questionnaire in 1976. Deaths from all sites of cancers in the subjects were observed over 27 years. Mortalities of several cancers in the subjects were compared with individuals in the Japanese population, calculating standardized mortality ratios (SMRs) using the general Japanese population as a standard. Subjects included 8,360 people (4,674 men). There were a total of 551 deaths (469 men) during the follow-up period, and 277 deaths (211 men) from all cancers. The male and female SMRs (95% CI) were 0.62 (0.58-0.66) and 0.25 (0.16-0.34) for all deaths, 0.46 (0.39-0.53) and 0.41 (0.35-0.53) for all cancers combined, 0.49 (0.35-0.63) and 0.40 (0.12-0.68) for stomach, 0.40 (0.24-0.56) and 0.30 (0.10-0.70) for lung, 0.56 (0.39-0.73) and 0.26 (0.02-0.76) for liver, 0.38 (0.16-0.60) and 0.30 (0.07-0.67) for colon, and 0.48 (0.08-0.88) and 0.22 (0.04-0.79) for blood cancers, respectively, with significantly fewer deaths than in the general populace. The female SMRs were 0.90 (0.74-4.06) for breast and 0.55 (0.06-1.04) for ovarian, lacking significance. Thus, no excess mortality of any cancer sites was observed compared with the general population in both Japan and Aichi Prefecture.