Preserved C-reactive protein responses to blood stream infections following tocilizumab treatment for COVID-19

Use of interleukin-6 receptor antibodies in the second and third trimester of pregnancy: a retrospective cohort study

BACKGROUND

A paucity of data exists to inform the use of interleukin (IL)-6 receptor antibodies (anti-IL-6) in pregnancy, particularly in the third trimester. This study aimed to describe outcomes of pregnant women and their neonates exposed to these medications given after the first trimester to treat COVID-19.

METHODS

In this retrospective cohort study, we included all women with COVID-19 who were treated with an anti-IL-6 during pregnancy at two tertiary hospitals in London, UK-Guy's and St Thomas' NHS Foundation Trust and Imperial College Healthcare NHS Trust-between March 1, 2020, and Sept 30, 2022. Maternal demographics, clinical data, administered medications, and maternal and neonatal outcomes were assessed for all included women via a review of medical records and through maternal medicine networks.

FINDINGS

25 women received an anti-IL-6 for COVID-19 in pregnancy during the study period and were followed up for 12 months. The group described were a population at high risk, with 24 requiring level two or three critical care. 24 women received tocilizumab and one received sarilumab. All women were prescribed at least three concomitant medications. 16 received the anti-IL-6 in the third trimester of pregnancy and nine during the seocnd trimester. There were no women with maternal neutropenia or pancytopenia; increases in liver enzymes in 16 of 20 women with available alanine aminotransferase data were in keeping with the severity of COVID-19 reported and all three women who developed a secondary bacterial infection mounted a C-reactive protein response. There was one maternal death due to COVID-19. All pregnancies resulted in livebirths and there was one twin pregnancy. 16 of 26 babies were born preterm. One baby died at age 6 months due to complications of extreme prematurity. A transient neonatal cytopenia was described in six of 19 babies in whom a full blood count was performed. Although these findings are likely to be in keeping with prematurity alone, we cannot exclude the possibility that transplacental transfer of anti-IL-6 was contributory.

INTERPRETATION

We report further data on the use of anti-IL-6 in the second and third trimesters of pregnancy for the management of COVID-19. When extrapolated, our data can inform shared decision making for individuals who would benefit from the use of anti-IL-6 into the third trimester of pregnancy for management of rheumatological disease.

FUNDING

None.

C-reactive protein-guided use of procalcitonin in COVID-19

Background

A low procalcitonin (PCT) concentration facilitates exclusion of bacterial co-infections in COVID-19, but high costs associated with PCT measurements preclude universal adoption. Changes in inflammatory markers, including C-reactive protein (CRP), can be concordant, and predicting low PCT concentrations may avoid costs of redundant tests and support more cost-effective deployment of this diagnostic biomarker.

Objectives

To explore whether, in COVID-19, low PCT values could be predicted by the presence of low CRP concentrations.

Methods

Unselected cohort of 224 COVID-19 patients admitted to hospital that underwent daily PCT and CRP measurements as standard care. Both 0.25 ng/mL and 0.5 ng/mL were used as cut-offs for positive PCT test results. Geometric mean was used to define high and low CRP values at each timepoint assessed.

Results

Admission PCT was <0.25 ng/mL in 160/224 (71.4%), 0.25–0.5 ng/mL in 27 (12.0%) and >0.5 ng/mL in 37 (16.5%). Elevated PCT was associated with increased risk of death (P = 0.0004) and was more commonly associated with microbiological evidence of bacterial co-infection (P < 0.0001). For high CRP values, significant heterogeneity in PCT measurements was observed, with maximal positive predictive value of 50% even for a PCT cut-off of 0.25 ng/mL. In contrast, low CRP was strongly predictive of low PCT concentrations, particularly <0.5 ng/mL, with a negative predictive value of 97.6% at time of hospital admission and 100% 48 hours into hospital stay.

Conclusions

CRP-guided PCT testing algorithms can reduce unnecessary PCT measurement and costs, supporting antimicrobial stewardship strategies in COVID-19.

Risk of Reactivation of Hepatitis B Virus (HBV) and Tuberculosis (TB) and Complications of Hepatitis C Virus (HCV) Following Tocilizumab Therapy: A Systematic Review to Inform Risk Assessment in the COVID-19 Era

Objectives: Tocilizumab (TCZ), an IL-6 receptor antagonist, is used in the treatment of severe COVID-19 caused by infection with SARS-CoV-2. However, unintended consequences of TCZ therapy include reactivation of tuberculosis (TB) or hepatitis B virus (HBV), and worsening of hepatitis C virus (HCV). We set out to assimilate existing data for these complications, in order to help inform evidence-based risk assessments for the use of TCZ, and thus to reduce the risk of serious but preventable complications. Methods: We searched the global WHO database of Individual Case Safety Reports (ICSRs) and adverse drug reactions (ADRs) ("VigiBase") and undertook a systematic literature review, in accordance with PRISMA guidelines. We generated mean cumulative incidence estimates for infection complications. Results: Mean cumulative incidence of HBV and TB were 3.3 and 4.3%, respectively, in patients receiving TCZ. Insufficient data were available to generate estimates for HCV. These estimates derive from heterogeneous studies pre-dating SARS-CoV-2, with differing epidemiology and varied approaches to screening and prophylaxis, so formal meta-analysis was not possible. Conclusions: We underline the need for careful individual risk assessment prior to TCZ prescription, and present an algorithm to guide clinical stratification. There is an urgent need for ongoing collation of safety data as TCZ therapy is used in COVID.