Zhao, Huaqing

ABSTRACTIntroductionLung transplantation has become increasingly utilized in patients with COVID‐19. While several single‐center and UNOS database studies have been published on lung transplants (LTs) for end‐stage lung disease (ESLD) from Coronavirus disease 2019 (COVID‐19), there is a lack of multi‐center and international data.MethodsThis is a multicenter analysis from 11 high‐volume lung transplant centers in the United States and Europe. Data were collected through the Multi‐Institutional ECLS Registry and stratified by ESLD due to COVID‐19 versus other etiologies. Demographics and clinical variables were compared using Chi‐square test and Fisher's exact test. Survival was assessed by Kaplan‐Meier curves and compared by log‐rank test with propensity score matching.ResultsOf 1606 lung transplant recipients, 46 (2.9%) were transplanted for ESLD from COVID‐19 compared to 1560 (97.1%) without a history of COVID‐19. Among COVID‐19 patients, 30 (65.2%) had COVID‐19‐associated ARDS and 16 (34.8%) had post‐COVID‐19 fibrosis. COVID‐19 patients had higher lung allocation scores (78.0 vs. 44.4, p < 0.0001), had severely limited functional status (37.0% vs. 2.9%, p < 0.0001), had higher preoperative ECMO usage (65.2% vs. 5.4%, p < 0.0001), and spent less time on the waitlist (32 vs. 137 days, p < 0.0001). A 30‐day survival was comparable between COVID‐19 and non‐COVID‐19 patients before (100% vs. 98.7%, p = 0.39) and after propensity matching (p = 0.15).ConclusionsPatients who received LTs due to COVID‐19 had short‐term survival comparable to that of patients without COVID‐19. Our findings support the idea that lung transplantation should be considered for select patients with ESLD due to COVID‐19.

Leukemia cells accumulate DNA damage but altered DNA repair mechanisms protect them from apoptosis. We showed here that formaldehyde generated by serine/one-carbon cycle metabolism contributed to accumulation of toxic DNA-protein crosslinks (DPCs) in leukemia cells, especially in driver clones harboring oncogenic tyrosine kinases [OTKs: FLT3(ITD), JAK2(V617F), BCR/ABL1]. To counteract this effect, OTKs enhanced the expression of DNA polymerase theta (POLq) by ERK1/2 serine/threonine kinase-dependent inhibition of c-CBL E3 ligase-mediated ubiquitination of POLq and its proteasomal degradation. Overexpression of POLq in OTK-positive cells resulted in efficient repair of DPC-containing DNA double-strand breaks (DSBs) by POLq-mediated end-joining (TMEJ). Transforming activity of OTKs and other leukemia-inducing oncogenes, especially of those causing inhibition of BRCA1/2 -mediated homologous recombination (HR) with and without concomitant inhibition of DNA-PK -dependent non-homologous end-joining (D-NHEJ), was abrogated in Polq-/- murine bone marrow cells. Genetic and pharmacological targeting of POLq polymerase and helicase activities revealed that both activities are promising targets in leukemia cells. Moreover, OTK inhibitor or DPC-inducing drug etoposide enhanced anti-leukemia effect of POLq inhibitor (POLqi) in vitro and in vivo. In conclusion, we demonstrated that POLq plays an essential role in protecting leukemia cells from metabolically induced toxic DNA lesions triggered by formaldehyde and that it can be targeted to achieve therapeutic effect.

Background. Lung transplantation in patients with systemic sclerosis (SSc) can be complicated by extrapulmonary manifestations of the disease, leading to concerns regarding posttransplant complications and outcomes. Methods. We conducted a web-based survey of adult lung transplant programs in the United States regarding their practices in patients with SSc. Results. Sixty percent (37/62) of the eligible centers responded to the survey, majority of the respondents were medical directors (81%). Most centers would consider transplanting patients with mild or moderate esophageal disease (92% or 75%, respectively) or gastroparesis (59%). A minority would consider patients with severe esophageal dysmotility (37%), digital ulcers (21%), or low body mass index (19%). Most centers conducted extensive pretransplant gastrointestinal evaluation and use a conservative feeding approach with prolonged nothing by mouth (83%) and postpyloric feeding (89%). Antireflux surgery is commonly considered (40%) with partial fundoplication being the procedure of choice (67%). Most respondents expected similar outcomes of acute or chronic rejection (81% and 51%, respectively), respiratory infections (76%), and 1-year survival (70%). Conclusions. Most US lung transplant centers do not universally exclude SSc from lung transplant listing, but most support extensive pretransplant gastrointestinal testing and a conservative approach to feeding in the early posttransplant period.

Catheter-directed thrombolysis (CDT) is being increasingly used for the treatment of proximal lower extremity (LE) deep venous thrombosis (DVT). However, sex differences in utilization and safety outcomes of CDT in these patients are unknown. The Nationwide Inpatient Sample (NIS) database was used to identify all patients with a principal discharge diagnosis of proximal LE or caval DVT who underwent CDT between January 2005 and December 2011 in the United States. We evaluated the comparative safety outcomes of CDT among a propensity-matched group of 1731 men versus 1731 women. Among 108,243 patients with proximal LE or caval DVT, 4826 patients (4.5%) underwent CDT. Overall, women underwent CDT less often compared to men (4.1% vs 4.9%, p<0.01, respectively). The rates of CDT increased between 2005 and 2011 for both women (2.1% to 5.9%, p<0.01) and men (2.5% to 7.5%, p<0.01). There was no significant difference in in-hospital mortality (1.2% vs 1.3%, p=0.76). Women were noted to have higher rates of blood transfusions (11.7% vs 8.8%, p<0.01), but lower rates of intracranial hemorrhage (0.5% vs 1.2%, p=0.03) and gastrointestinal bleeding (0.9% vs 2.2%, p<0.01) compared with men. Women were more likely to undergo inferior vena cava filter placement (37.0% vs 32.1%, p<0.01). In this large nationwide cohort, women with proximal DVT were less likely to receive CDT compared to men. Although mortality rates were similar, women were noted to have higher blood transfusion rates while men had more episodes of intracranial and gastrointestinal bleeding.

Background— The use of catheter-directed thrombolysis (CDT) in the treatment of acute proximal lower-extremity deep vein thrombosis is increasing in the United States and has been linked to higher bleeding rates. Whether this relationship is interrelated with institution volume of CDT is unknown. Methods and Results— The Nationwide Inpatient Sample database was used to identify all patients admitted with a principal diagnosis of proximal or inferior vena caval deep vein thrombosis and treated with CDT from 2005 to 2010. Institutions were divided into high-volume (≥6 procedures a year) and low-volume (<6 procedures a year) centers. Propensity score matching was used to create 2 matched groups for comparative analysis. A total of 90 618 patients were hospitalized for proximal lower-extremity deep vein thrombosis, and 3649 patients (4.1%) underwent CDT. In-hospital mortality was significantly lower at high-volume centers (0.6% versus 1.5%; P =0.04) with a trend toward lower intracranial hemorrhage rates compared with low-volume centers (0.4% versus 1%; P =0.07). No significant difference was seen with blood transfusion (10.4% versus 10.8%; P =0.70), gastrointestinal bleeding (1.4% versus 1.8%; P =0.35), or pulmonary embolism rates (18.4% versus 17.9%; P =0.72). Median length of stay was similar (6 days) and hospital charges were higher ($65 500 versus $75 870) at high-volume centers. Conclusions— In this observational study, we found that an increase in institutional volume of CDT was associated with lower in-hospital mortality and lower intracranial hemorrhage rates. Further studies are needed to assess whether standardization of CDT protocols across all institutions in the United States improves outcomes.