Noninferiority of Subcutaneous Versus Intravenous Casirivimab/Imdevimab for Outpatient Treatment of SARS-CoV-2 in a Real-World Setting.

Monoclonal antibody (mAb) therapy has emerged as one of the mainstay treatment options for SARS-CoV-2. To improve speed of delivery and decrease bedside nursing needs, subcutaneous (SC) delivery of mAbs has been explored as an alternative to standard intravenous (IV) administration. To date, data regarding the effectiveness of SC compared with IV mAb are lacking. This retrospective cohort analysis conducted between April 2021 and August 2021 compared hospitalization rates among patients receiving IV versus SC administration of casirivimab/imdevimab (Regen-COV) at a single institution in Arkansas. Casirivimab/imdevimab was a promising mAb therapy utilized during the height of the Delta variant surge of the SARS-CoV-2 pandemic. Before resistance developed by the Omicron variant, casirivimab/imdevimab was utilized for outpatient treatment of SARS-CoV-2 patients at risk of deterioration. Primary outcomes of this investigation were the 30-day post-treatment rate of hospitalization and intensive care unit (ICU) care during hospitalization. There was no increased risk of hospitalization or ICU care with SC administration compared with IV administration. As SARS-CoV-2 continues to mutate into variants such as Omicron and develop resistance to existing mAbs, these preliminary findings of noninferiority of SC versus IV warrant ongoing investigation into SC administration of other mAbs.

Case of ehrlichiosis induced Guillain-Barre Syndrome in a 71 year-old female.

Guillain-Barre Syndrome (GBS) is a rare autoimmune demyelinating polyradiculoneuropathy that causes an ascending paralysis and flaccid weakness. Tick paralysis is a mimic of GBS as symptoms include generalized weakness and paralysis. However, symptom onset and timing as well as lab findings can distinguish between them. We present a case of a 71-year-old female who complained of generalized weakness and dizziness starting three weeks prior to admission. During that time, she had fevers and chills and a questionable insect bite. Her lab values indicated thrombocytopenia and elevated liver enzymes. PCR titers were positive for ehrlichiosis and she was started on doxycycline then discharged. She returned over a week later with worsening symptoms despite treatment. There was concern she may had Heartland or Bourbon virus but titers were negative. Her neurological exam showed numbness and areflexia in her lower extremities which progressed since her first encounter. She was given IVIG and her symptoms improved and recovered slowly. Although ehrlichiosis is not a common cause for GBS, the pathogenesis is like Lyme disease or Campylobacter jejuni. This patient had clinical symptoms that were like tick-borne illness yet as her disease progressed, it illustrated the need for an expanded differential diagnosis. There is very little literature about ehrlichia inducing GBS. It is important to keep a broad differential as sometimes common syndromes do not always come from common pathogens and with the COVID-19 pandemic having similar results, we are learning new things that may potentially be new standards in medical education.