Role of IP-10 to Predict Clinical Progression and Response to IL-6 Blockade With Sarilumab in Early COVID-19 Pneumonia. A Subanalysis of the SARICOR Clinical Trial.

Background: The Clinical Trial of Sarilumab in Adults With COVID-19 (SARICOR) showed that patients with coronavirus disease 2019 (COVID-19) pneumonia and increased levels of interleukin (IL)-6 might benefit from blockade of the IL-6 pathway. However, the benefit from this intervention might not be uniform. In this subanalysis, we sought to determine if other immunoactivation markers, besides IL-6, could identify which subgroup of patients benefit most from this intervention. Methods: The SARICOR trial was a phase II, open-label, multicenter, controlled trial (July 2020-March 2021) in which patients were randomized to receive usual care (UC; control group), UC plus a single dose of sarilumab 200 mg (sarilumab-200 group), or UC plus a single dose of sarilumab 400 mg (sarilumab-400 group). Patients who had baseline serum samples for cytokine determination (IL-8, IL-10, monocyte chemoattractant protein-1, interferon-inducible protein [IP]-10) were included in this secondary analysis. Progression to acute respiratory distress syndrome (ARDS) according to cytokine levels and treatment received was evaluated. Results: One hundred one (88%) of 115 patients enrolled in the SARICOR trial had serum samples (control group: n = 33; sarilumab-200: n = 33; sarilumab-400: n = 35). Among all evaluated biomarkers, IP-10 showed the strongest association with treatment outcome. Patients with IP-10 ≥2500 pg/mL treated with sarilumab-400 had a lower probability of progression (13%) compared with the control group (58%; hazard ratio, 0.19; 95% CI, 0.04-0.90; P = .04). Conversely, patients with IP-10 <2500 pg/mL did not show these differences. Conclusions: IP-10 may predict progression to ARDS in patients with COVID-19 pneumonia and IL-6 levels >40 pg/mL. Importantly, IP-10 value <2500 pg/mL might discriminate those individuals who might not benefit from sarilumab therapy among those with high IL-6 levels.

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19.

BACKGROUND: We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases. METHODS: We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded. RESULTS: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P = 1.1 × 10-4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3-8.2], P = 2.1 × 10-4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1-2635.4], P = 3.4 × 10-3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3-8.4], P = 7.7 × 10-8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10-5). CONCLUSIONS: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19.

Background: We previously reported inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity in 1-5% of unvaccinated patients with life-threatening COVID-19, and auto-antibodies against type I IFN in another 15-20% of cases. Methods: We report here a genome-wide rare variant burden association analysis in 3,269 unvaccinated patients with life-threatening COVID-19 (1,301 previously reported and 1,968 new patients), and 1,373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. A quarter of the patients tested had antibodies against type I IFN (234 of 928) and were excluded from the analysis. Results: No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7 , with an OR of 27.68 (95%CI:1.5-528.7, P= 1.1×10 -4 ), in analyses restricted to biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70 [95%CI:1.3-8.2], P= 2.1×10 -4 ). Adding the recently reported TYK2 COVID-19 locus strengthened this enrichment, particularly under a recessive model (OR=19.65 [95%CI:2.1-2635.4]; P= 3.4×10 -3 ). When these 14 loci and TLR7 were considered, all individuals hemizygous ( n =20) or homozygous ( n =5) for pLOF or bLOF variants were patients (OR=39.19 [95%CI:5.2-5037.0], P =4.7×10 -7 ), who also showed an enrichment in heterozygous variants (OR=2.36 [95%CI:1.0-5.9], P =0.02). Finally, the patients with pLOF or bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P= 1.68×10 -5 ). Conclusions: Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

Early Use of Sarilumab in Patients Hospitalized with COVID-19 Pneumonia and Features of Systemic Inflammation: the SARICOR Randomized Clinical Trial.

The objective of this study was to investigate the efficacy and safety of early treatment with sarilumab, added to standard of care (SOC), in hospitalized adults with COVID-19. Methods included phase II, open-label, randomized, controlled clinical trial of hospitalized patients with COVID-19 pneumonia and interleukin (IL)-6 levels ≥ 40 pg/mL and/or d-dimer > 1,500 ng/mL. Participants were randomized (1:1:1) to receive SOC (control group), SOC plus a single subcutaneous dose of sarilumab 200 mg (sarilumab-200 group), or SOC plus a single subcutaneous dose of sarilumab 400 mg (sarilumab-400 group). The primary outcome variable was the development of acute respiratory distress syndrome (ARDS) requiring high-flow nasal oxygenation (HFNO), non-invasive mechanical ventilation (NIMV) or invasive mechanical ventilation (IMV) at day 28. One-hundred and 15 participants (control group, n = 39; sarilumab-200, n = 37; sarilumab-400, n = 39) were included. At randomization, 104 (90%) patients had supplemental oxygen and 103 (90%) received corticosteroids. Eleven (28%) patients in the control group, 10 (27%) in sarilumab-200, and five (13%) in sarilumab-400 developed the primary outcome (hazard ratio [95% CI] of sarilumab-400 vs control group: 0.41 [0.14, 1.18]; P = 0.09). Seven (6%) patients died: three in the control group and four in sarilumab-200. There were no deaths in sarilumab-400 (P = 0.079, log-rank test for comparisons with the control group). In patients recently hospitalized with COVID-19 pneumonia and features of systemic inflammation, early IL-6 blockade with a single dose of sarilumab 400 mg was safe and associated with a trend for better outcomes. (This study has been registered at ClinicalTrials.gov under identifier NCT04357860.).

CREB-binding protein (CBP) gene family regulates planarian survival and stem cell differentiation.

In developmental biology, the regulation of stem cell plasticity and differentiation remains an open question. CBP(CREB-binding protein)/p300 is a conserved gene family that functions as a transcriptional co-activator and plays important roles in a wide range of cellular processes, including cell death, the DNA damage response, and tumorigenesis. The acetyl transferase activity of CBPs is particularly important, as histone and non-histone acetylation results in changes in chromatin architecture and protein activity that affect gene expression. Many studies have described the conserved functions of CBP/p300 in stem cell proliferation and differentiation. The planarian Schmidtea mediterranea is an excellent model for the in vivo study of the molecular mechanisms underlying stem cell differentiation during regeneration. However, how this process is regulated genetically and epigenetically is not well-understood yet. We identified 5 distinct Smed-cbp genes in S. mediterranea that show different expression patterns. Functional analyses revealed that Smed-cbp-2 appears to be essential for stem cell maintenance. On the other hand, the silencing of Smed-cbp-3 resulted in the growth of blastemas that were apparently normal, but remained largely unpigmented and undifferentiated. Smed-cbp-3 silencing also affected the differentiation of several cell lineages including neural, epidermal, digestive, and excretory cell types. Finally, we analysed the predicted interactomes of CBP-2 and CBP-3 as an initial step to better understand their functions in planarian stem cell biology. Our results indicate that planarian cbp genes play key roles in stem cell maintenance and differentiation.