Background While hepatitis A and B are well-known causes of acute liver failure (ALF), few well-documented cases of hepatitis C virus (HCV) infection (absent preexisting liver disease or other liver insults) have been described that result in ALF. We reviewed the Acute Liver Failure Study Group registry for evidence of HCV as a primary or contributing cause to ALF. Methods From January 1998 to January 2017, 2,332 patients with ALF (INR ≥ 1.5, any degree of hepatic encephalopathy) and 667 with acute liver injury (ALI; INR ≥ 2.0, no hepatic encephalopathy) were enrolled. Anti-HCV testing was done routinely, with confirmatory RT-PCR testing for HCV RNA where necessary. Results A total of 136 patients were anti-HCV-antibody positive, as follows: 56 HCV RNA negative, 65 HCV RNA positive, and 8 with no result nor sera available for testing. Only three subjects with ALI/ALF were determined to represent acute HCV infection. Case 1: 47-year-old female with morbid obesity (BMI 52.4) developed ALF and recovered, experiencing anti-HCV seroconversion. Case 2: 37-year-old female using cocaine presented with ALI and fully recovered. Case 3: 54-year-old female developed ALF requiring transplantation and was anti-HCV negative but viremic prior to transplant experiencing anti-HCV seroconversion thereafter. Among 1636 APAP overdose patients, the 52 with concomitant chronic HCV had higher 3-week mortality than the 1584 without HCV (31% vs 17%, p = 0.01). Conclusions ALI/ALF solely related to acute hepatitis C infection is very rare. Chronic HCV infection, found in at least 65 (2.2%) of ALI/ALF patients studied, contributed to more severe outcomes in APAP ALI/ALF; ClinicalTrials.gov number, NCT000518440. Trial Registration ClinicalTrials.gov number NCT000518440.

Systemic sclerosis is a rare connective tissue disease; and interstitial lung disease (SSc–ILD) is associated with significant morbidity and mortality. There are no clinical, radiologic features, nor biomarkers that identify the specific time when patients are at risk for progression at which the benefits from treatment outweigh the risks. Our study aimed to identify blood protein biomarkers associated with progression of interstitial lung disease in patients with SSc–ILD using an unbiased, high-throughput approach. We classified SSc–ILD as progressive or stable based on change in forced vital capacity over 12 months or less. We profiled serum proteins by quantitative mass spectrometry and analyzed the association between protein levels and progression of SSc–ILD via logistic regression. The proteins associated with at a p value of < 0.1 were queried in the ingenuity pathway analysis (IPA) software to identify interaction networks, signaling, and metabolic pathways. Through principal component analysis, the relationship between the top 10 principal components and progression was evaluated. Unsupervised hierarchical clustering with heatmapping was done to define unique groups. The cohort consisted of 72 patients, 32 with progressive SSc–ILD and 40 with stable disease with similar baseline characteristics. Of a total of 794 proteins, 29 were associated with disease progression. After adjusting for multiple testing, these associations did not remain significant. IPA identified five upstream regulators that targeted proteins associated with progression, as well as a canonical pathway with a higher signal in the progression group. Principal component analysis showed that the ten components with the highest Eigenvalues represented 41% of the variability of the sample. Unsupervised clustering analysis revealed no significant heterogeneity between the subjects. We identified 29 proteins associated with progressive SSc–ILD. While these associations did not remain significant after accounting for multiple testing, some of these proteins are part of pathways relevant to autoimmunity and fibrogenesis. Limitations included a small sample size and a proportion of immunosuppressant use in the cohort, which could have altered the expression of inflammatory and immunologic proteins. Future directions include a targeted evaluation of these proteins in another SSc–ILD cohort or application of this study design to a treatment naïve population.