Retinopathy Associated with Adjuvant Interferon in a Patient with Malignant Melanoma: A Case Report and Review of the Literature

Interferons are kinds of proteins with immuneregulatory, antiviral and anti-proliferative functions. Interferons are widely used worldwide for the treatment of many diseases including cancer, hepatit C and immune mediated disease such as multiple sclerosis. Long-term use of interferons have some side effects. However, interferons have ophthalmologic side effects. Ocular toxicity may occur at any time during treatment. There is no association between the dose or duration of interferon treatment and ocular toxicity. Although visual acuity returns to normal in most patients when interferon is discontinued, vision loss may be permanent.

2238. Evaluation of Adjuvant Interferon-Gamma-Level Assessment to Improve the Performance of Procalcitonin Testing in Hospitalized Bacteremic Patients

Background Although procalcitonin-guided antimicrobial stewardship has had proven utility in emergency and ICU settings, it is still not widely adopted outside these areas. One limitation to a more universal uptake has been the unreliable performance in discriminating bacterial infected from uninfected individuals. Viral infections have been noted to suppress procalcitonin (PCT) levels through Interferon-gamma (IFN-G)-mediated inhibition of procalcitonin release from parenchymal cells. Unfortunately, clinical application algorithms do not assess INF-G levels at the time evaluation thus treating providers are unable to distinguish a true-negative test from a false-negative test resulting from INF-G-mediated procalcitonin suppression This undermines the performance of PCT, particularly in patients with bacterial and viral co-infections. We hypothesized that adjuvant interferon gamma testing could improve the performance of PCT. To test this hypothesis we prospectively enrolled bacteremic hospitalized patients along with culture-negative controls and then assessed the performance of PCT with adjuvant IFN-G testing. Methods 69 hospitalized patients with bacteremia and 32 culture-negative controls were enrolled. Demographic and clinical parameters were compared between groups alongside INFG and PCT levels Parametric and non-parametric statistical tests were performed where appropriate. Test performance was evaluated by constructing receiver operator curves (ROCs) for PCT, INF-G, and a combination of PCT+INF-G. Results Of 101 patients enrolled, the mean age was 49.46 ± 13.6 years with 47% being female. The following were comparative statistics between the culture-positive vs. culture-negative group: mean age 52.1 ± 15.7 vs. 46.4 ± 14.2 years, P = 0.56; WBC 11.9 ± 9.5 vs. 9.5±5.1, P = 0.170; ANC 8,466 ± 5,686 vs. 8,189 ± 4,769, P = 0.907; eGFR 73.2 ± 23 vs. 74.5 ± 26.1, P = 0.644; PCT 2.79 ± 5.87 vs. 0.71 ± 1.79, P = 0.03. Of these 57 patients had INF-G and PCT values available and their corresponding ROCs are shown in figure. Conclusion Our interim results indicate adjuvant INF-G testing may not improve the performance of procalcitonin in hospitalized bacteremic patients. The additional samples are being analyzed to confirm these findings. Disclosures All authors: No reported disclosures.