Uristix reagent strips

C57BL/6 (B6) mice homozygous for loxP-flanked caspase-8 allele (Casp8^fl/fl) [11 (link)] were crossed with mice expressing Cre under control of murine lysozyme M gene promoter (Cre^LysM; The Jackson Laboratory, Bar Harbor, ME, USA), generating Cre^LysMCasp8^fl/fl mice. Cre^LysMCasp8^fl/fl mice were crossed with RIPK3^−/− (Genentech, South San Francisco, CA, USA) to generate RIPK3^−/−Cre^LysMCasp8^fl/fl mice. OT-II/RAG^−/− and B6.CD45.1 were purchased from The Jackson Laboratory. B6.CD45.1/2 mice were generated from a cross of B6 (The Jackson Laboratory) and B6.CD45.1 mice. Female mice were used in all studies. Proteinuria was assessed using Uristix reagent strips (Siemens Healthcare Diagnostics, Tarrytown, NY, USA). Transnetyx (Cordova, TN, USA) performed all genotyping of mice. All animal experiments were approved by the Northwestern University Institutional Animal Care and Use Committee.

Participants were recruited from a variety of settings within hospitals, antenatal clinics, maternity assessment units, and inpatient wards. Women interested in taking part were provided with information about the study prior to written informed consent. Participants were provided with simple instructions for protein testing (Figure S1), a urine sample pot with a funnel, and dipstick tests (ALBUSTIX reagent strips, Siemens, Surrey, UK) and undertook sample testing in the clinic or at the bedside on the same day they were recruited. Participants were asked to record their urinary proteinuria result on a case report form (CRF). Healthcare professionals, masked to the participant’s result, re‐tested the same urine sample using the same dipstick method. The same urine sample was then further tested using a dipstick test (URISTIX reagent strips; SIEMENS) in an automated colorimetric reader (Clinitek Status + Analyser; Siemens) by a member of the study team before being sent to the laboratory for PCR and ACR testing by a member of the laboratory team who were masked to other results. Urine samples were stored in line with current guidance and tested expediently in order to minimise sample degradation.¹²