Effects of Intravenous Immunoglobulin on the Course of Severe COVID-19: Results From a Retrospective Data Analysis of a Patient Cohort in Turkey Treated With or Without Octagam®

Background: There is some evidence from case reports and a few studies in China that critically ill COVID-19 patients may benefit from treatment with intravenous immunoglobulins (IVIG). We compared clinical outcomes and biomarkers in a Turkish cohort of patients with severe COVID-19 who were treated with the institution's standard of care (SOC), either alone or in combination with IVIG. Methods: : Data from COVID-19 patients treated in two intensive care units at the University hospital of Istanbul was analyzed retrospectively. Patients received preliminary SOC according to the institution's treatment algorithm, to which Octagam 5% at 30 g/day for 5 days was added in one of the two wards. Both groups were compared regarding baseline characteristics, survival, and changes in inflammation markers (C-reactive protein=CRP, ferritin, procalcitonin, interleukin-6, D‑dimer, leukocytes). Imbalance in baseline APACHE II scores was addressed by propensity-score-matching; otherwise Kaplan-Meier and multiple logistic regression models were used. Results: : Data from 93 patients was analyzed, 51 had received IVIG and 42 had not. About 75% of patients were male and both groups had comparable body mass index (BMI) and blood group distribution. IVIG-treated patients were younger (means 65 vs. 71 years) and had slightly lower baseline disease scores (APACHE II: 20.6 vs. 22.4; SOFA: 5.0 vs. 7.0). Overall survival (OS) was 61% in the IVIG and 38% in the control group. After controlling for imbalances at baseline, there was still a trend for better OS (OR: 2.2, 95%CI: 0.9-5.4, p=0.091) and a significantly longer median survival time with IVIG (68 vs. 18 days, p=0.014). IVIG significantly reduced CRP levels, but had no relevant effect on other inflammation markers. Conclusion: Adjunct treatment with IVIG might add to the COVID-19 armamentarium, but results need to be confirmed in a randomized, controlled trial.