Developing a Tool for Differentiation Between Bacterial and Viral Respiratory Infections Using Myxovirus Resistance Protein A and C-Reactive Protein.

INTRODUCTION: The aim was to assess the performance of a blood assay combining measurements of MxA (myxovirus resistance protein A) and CRP (C-reactive protein) to differentiate viral from bacterial respiratory infections. METHODS: In a prospective study, MxA and CRP were measured in the blood by the AFIAS panel in adults admitted with respiratory infection. Patients were split into discovery and validation cohorts. Final diagnosis was adjudicated by a panel of experts. Microbiology-confirmed cases comprised the discovery cohort, and infections adjudicated as highly probable viral or bacterial comprised the validation cohort. RESULTS: A total of 537 patients were analyzed: 136 patients were adjudicated with definitive viral infections and 131 patients with definitive bacterial infections. Using logistic regression analysis, an equation was developed to calculate the probability for bacterial infection using the absolute value of MxA and CRP. Calculated probability ≥ 0.5 and/or MxA to CRP ratio less than 2 applied as the diagnostic rule for bacterial infections. This rule provided 91.6% sensitivity and 90.4% negative predictive value for the diagnosis of bacterial infections. This diagnostic sensitivity was confirmed in the validation cohort. A MxA/CRP ratio less than 0.15 was associated with unfavorable outcome. CONCLUSION: The calculation of the probability for bacterial infection using MxA and CRP may efficiently discriminate between viral and bacterial respiratory infections.

Clarithromycin for early anti-inflammatory responses in community-acquired pneumonia in Greece (ACCESS): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Addition of macrolide antibiotics to ß-lactam antibiotics for the treatment of patients in hospital with community-acquired pneumonia is based on results from observational studies and meta-analyses rather than randomised clinical trials. We investigated if addition of the macrolide clarithromycin to treatment with a ß-lactam antibiotic in this population could improve early clinical response-the new regulatory endpoint for community-acquired pneumonia-and explored the possible contribution of modulation of the inflammatory host response to that outcome. METHODS: The ACCESS trial was a phase 3 prospective, double-blind, randomised controlled trial, in which adults in hospital with community-acquired pneumonia who had systemic inflammatory response syndrome, Sequential Organ Failure Assessment (SOFA) score of 2 or more, and procalcitonin 0·25 ng/mL or more were enrolled in 18 internal medicine departments of public Greek hospitals. Patients were randomly assigned (1:1) by computer-generated block randomisation to standard of care medication (including intravenous administration of a third-generation cephalosporin or intravenous administration of ß-lactam plus ß-lactamase inhibitor combination) plus either oral placebo or oral clarithromycin 500 mg twice daily for 7 days. Investigators, staff, and patients were masked to group allocation. The primary composite endpoint required that patients fulfilled both of the following conditions after 72 hours (ie, day 4 of treatment): (1) decrease in respiratory symptom severity score of 50% or more as an indicator of early clinical response and (2) decrease in SOFA score of at least 30% or favourable procalcitonin kinetics (defined as ≥80% decrease from baseline or procalcitonin <0·25 ng/mL), or both, as an indicator of early inflammatory response. Participants who were randomly assigned and received allocated treatment were included in the primary analysis population. This trial is complete and is registered with the EU Clinical Trials Register (2020-004452-15) and ClinicalTrials.gov (NCT04724044). FINDINGS: Patients were enrolled between Jan 25, 2021, and April 11, 2023, and 278 individuals were randomly allocated to receive standard of care in combination with either clarithromycin (n=139) or placebo (n=139). 134 patients in the clarithromycin group (five withdrew consent) and 133 patients in the placebo group (six withdrew consent) were included in the analysis of the primary endpoint. The primary endpoint was met in 91 (68%) patients in the clarithromycin group and 51 (38%) patients in the placebo group (difference 29·6% [95% CI 17·7-40·3]; odds ratio [OR] 3·40 [95% CI 2·06-5·63]; p<0·0001). Serious treatment-emergent adverse events (TEAEs) occurred in 58 (43%) patients in the clarithromycin group and 70 (53%) patients in the placebo group (difference 9·4% [95% CI -2·6 to 20·9]; OR 0·67 [95% CI 0·42 to 1·11]; p=0·14). None of the serious TEAEs was judged to be related to treatment assignment. INTERPRETATION: Addition of clarithromycin to standard of care enhances early clinical response and attenuates the inflammatory burden of community-acquired pneumonia. The mechanism of benefit is associated with changes in the immune response. These findings suggest the importance of adding clarithromycin to ß-lactams for treatment of patients in hospital with community-acquired pneumonia to achieve early clinical response and early decrease of the inflammatory burden. FUNDING: Hellenic Institute for the Study of Sepsis and Abbott Products Operations.

Cancer-associated retinopathy 4 years after surgery for ovarian cancer.

A 71-year-old woman presented with progressive, bilateral, blurred vision and nyctalopia for the last 6 months. Her past medical history included total hysterectomy and chemotherapy for ovarian cancer 4 years ago, without metastases. Optical coherence tomography revealed outer retinal layers' thinning bilaterally, while diffuse retinal pigment epithelium abnormalities were found in fundus autofluorescence. Full-field electroretinogram showed abnormalities in both a- and b-waves with significant reduction of retinal sensitivity, affecting however more the rod system. The patient was positive for alpha-enolase and was diagnosed with cancer-associated retinopathy (CAR), which developed 4-year primary cancer. Computerized tomography scan revealed an enlarged para-aortic lymph node at the left kidney, and the patient was started on chemotherapy, combined with immunosuppressive treatment. In conclusion, CAR should be suspected in patients experiencing unexplained visual disturbances, especially in the context of previous cancer.