Interferons interfere with lung repair: Interferons (IFNs) are central to antiviral immunity. Viral recognition elicits IFN production, which in turn triggers the transcription of IFN-stimulated genes (ISGs), which engage in various antiviral functions. Type I IFNs (IFN-α and IFN-β) are widely expressed and can result in immunopathology during viral infections. By contrast, type III IFN (IFN-λ) responses are primarily restricted to mucosal surfaces and are thought to confer antiviral protection without driving damaging proinflammatory responses. Accordingly, IFN-λ has been proposed as a therapeutic in coronavirus disease 2019 (COVID-19) and other such viral respiratory diseases (see the Perspective by Grajales-Reyes and Colonna). Broggi et al. report that COVID-19 patient morbidity correlates with the high expression of type I and III IFNs in the lung. Furthermore, IFN-λ secreted by dendritic cells in the lungs of mice exposed to synthetic viral RNA causes damage to the lung epithelium, which increases susceptibility to lethal bacterial superinfections. Similarly, using a mouse model of influenza infection, Major et al. found that IFN signaling (especially IFN-λ) hampers lung repair by inducing p53 and inhibiting epithelial proliferation and differentiation. Complicating this picture, Hadjadj et al. observed that peripheral blood immune cells from severe and critical COVID-19 patients have diminished type I IFN and enhanced proinflammatory interleukin-6– and tumor necrosis factor-α–fueled responses. This suggests that in contrast to local production, systemic production of IFNs may be beneficial. The results of this trio of studies suggest that the location, timing, and duration of IFN exposure are critical parameters underlying the success or failure of therapeutics for viral respiratory infections. Science , this issue p. 706 , p. 712 , p. 718 ; see also p. 626

Introduction: An over-expression of CD19 has been shown in B cells of systemic sclerosis (SSc) and B cells are thought to contribute to the induction of skin fibrosis in the tight skin mouse model. The aim was to define the outcome on safety and the change in skin score after rituximab therapy in SSc patients and to correlate the clinical characteristics with the levels of interleukin (IL)-6 and with the immune cell infiltrate detected by immunohistochemistry. Methods: Nine patients with SSc with mean age 40.9 ± 11.1 years were treated with anti-CD20, 1 g at time 0 and after 14 days. Skin biopsy was performed at baseline and during the follow-up. B-cell activating factor (BAFF) and IL-6 levels were also determined at the follow-up times. Results: After 6 months patients presented a median decrease of the skin score of 43.3% (range 21.1-64.0%), and a decrease in disease activity index and disease severity index. IL-6 levels decreased permanently during the follow up. After treatment, a complete depletion of peripheral blood B cells was observed in all but 2 patients. Only 3 patients presented CD20 positive cells in the biopsy of the involved skin at baseline. Conclusions: Anti-CD20 treatment has been well tolerated and SSc patients experienced an improvement of the skin score and of clinical symptoms. The clear fall in IL-6 levels could contribute to the skin fibrosis improvement, while the presence of B cells in the skin seems to be irrelevant with respect to the outcome after B cell depletion. Trial registration: ISRCTN77554566.

Objective: To assess fetal and maternal outcomes in women with systemic sclerosis (SSc).Methods: Prospectively collected data on 99 women with SSc from 25 Italian centers were analyzed retrospectively. Women with SSc were observed during 109 pregnancies (from 2000 to 2011), and outcomes were compared to those in the general obstetric population (total of 3,939 deliveries). The maternal age at conception was a mean ± SD 31.8 ± 5.3 years, and the median disease duration at conception was 60 months (range 2–193 months).Results: SSc patients, compared to the general obstetric population, had a significantly increased frequency of preterm deliveries (25% versus 12%) and severe preterm deliveries (<34 weeks of gestation) (10% versus 5%), intrauterine growth restriction (6% versus 1%), and babies with very‐low birth weight (5% versus 1%). Results of multivariable analysis showed that corticosteroid use was associated with preterm deliveries (odds ratio [OR] 3.63, 95% confidence interval [95% CI] 1.12–11.78), whereas the use of folic acid (OR 0.30, 95% CI 0.10–0.91) and presence of anti–Scl‐70 antibodies (OR 0.26, 95% CI 0.08–0.85) were protective. The disease remained stable in most SSc patients, but there were 4 cases of progression of disease within 1 year from delivery, all in anti–Scl‐70 antibody–positive women, 3 of whom had a disease duration of <3 years.Conclusion: Women with SSc can have successful pregnancies, but they have a higher‐than‐normal risk of preterm delivery, intrauterine growth restriction, and babies with very‐low birth weight. Progression of the disease during or after pregnancy is rare, but possible. High‐risk multidisciplinary management should be standard for these patients, and pregnancy should be avoided in women with severe organ damage and postponed in women with SSc of recent onset, particularly if the patient is positive for anti–Scl‐70 antibodies.