Computed Tomography of the Chest to Screen for Interstitial Lung Disease in Patients With Systemic Sclerosis at Expert Scleroderma Centers in the United States.

OBJECTIVE: Although a high-resolution computed tomography (HRCT) scan of the chest is the gold standard test for the detection of interstitial lung disease (ILD), there is no consensus among rheumatologists regarding the use of HRCT to screen for ILD in their patients with systemic sclerosis (SSc). The aims of this study were to describe the HRCT ordering practices at SSc centers in the United States and to determine which patient characteristics are associated with HRCT performance. METHODS: We performed a prospective cohort study of patients with SSc enrolled in the US-based Collaborative National Quality and Efficacy Registry (CONQUER). We performed univariate logistic regression followed by multivariable logistic regression to determine which patient characteristics were associated with HRCT performance. RESULTS: Of the 356 patients with SSc enrolled in CONQUER, 286 (80.3%) underwent HRCT at some point during their disease course. On multivariable analyses, missing total lung capacity percent predicted (odds ratio [OR] 3.26, 95% confidence interval [CI]: 1.53-7.41, P = 0.007) was positively associated with ever having undergone HRCT, whereas a positive anti-centromere antibody (OR 0.27, 95% CI: 0.12-0.61, P = 0.008) and missing forced vital capacity percent predicted (OR 0.29, 95% CI: 0.10-0.80, P = 0.005) were negatively associated with ever having undergone HRCT. There was a trend toward a positive association between crackles on pulmonary exam and ever having undergone HRCT (OR 2.28, 95% CI: 0.97-6.05, P = 0.058), although this relationship did not reach statistical significance. CONCLUSION: The majority of patients with SSc enrolled in CONQUER underwent HRCT. A positive anti-centromere antibody was the key clinical variable inversely associated with performance of HRCT.

Multiple isoforms of CDC25 oppose ATM activity to maintain cell proliferation during vertebrate development.

The early development of vertebrate embryos is characterized by rapid cell proliferation necessary to support the embryo's growth. During this period, the embryo must maintain a balance between ongoing cell proliferation and mechanisms that arrest or delay the cell cycle to repair oxidative damage and other genotoxic stresses. The ataxia-telangiectasia mutated (ATM) kinase is a critical regulator of the response to DNA damage, acting through downstream effectors, such as p53 and checkpoint kinases (CHK) to mediate cell-cycle checkpoints in the presence of DNA damage. Mice and humans with inactivating mutations in ATM are viable but have increased susceptibility to cancers. The possible role of ATM in limiting cell proliferation in early embryos has not been fully defined. One target of ATM and CHKs is the Cdc25 phosphatase, which facilitates cell-cycle progression by removing inhibitory phosphates from cyclin-dependent kinases (CDK). We have identified a zebrafish mutant, standstill, with an inactivating mutation in cdc25a. Loss of cdc25a in the zebrafish leads to accumulation of cells in late G(2) phase. We find that the novel family member cdc25d is essential for early development in the absence of cdc25a, establishing for the first time that cdc25d is active in vivo in zebrafish. Surprisingly, we find that cell-cycle progression in cdc25a mutants can be rescued by chemical or genetic inhibition of ATM. Checkpoint activation in cdc25a mutants occurs despite the absence of increased DNA damage, highlighting the role of Cdc25 proteins to balance constitutive ATM activity during early embryonic development.