Determination of plasma concentration of Belimumab by LC-MS/MS: Method development, validation, and clinical application

INTRODUCTION

Belimumab is a monoclonal antibody against B cell activating factor (BLyS). This monoclonal antibody (mAb) has been shown to be effective in reducing disease activity in patients with systemic lupus erythematosus (SLE). Belimumab is available in two forms as a lyophilized powder for intravenous (IV) use, or single-dose syringe for subcutaneous (SC) use. The aim of this study was to develop and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantitation of belimumab in human serum.

MATERIAL AND METHODS

All analyses relied on nano-surface and molecular-orientation limited (nSMOL) proteolysis coupled with LC-MS/MS. Quantifications was performed in multiple reactions monitoring (MRM) mode, and electrospray ionization was conducted in positive mode.

RESULTS

Belimumab was quantified with signature peptide QAPGQGLEWMGGIPFGTAK and normalized using P14R. The total run time per assay was 10 min. Linearity was measured from 5 to 800 μg/mL (r² > 0.995). Accuracy and precision based on three quality control levels range from 11.2 - 9.51 % and 1.24 - 13.12 % respectively. The carryover was less than 7 %. In all, 87 patient samples were processed (65, IV; 22, SC). Mean concentration of belimumab was significantly higher for SC (93.0 ± 74.0 µg/mL) than for IV (67.4 ± 38.9 µg/mL) administration.

CONCLUSION

We have developed the first method of belimumab quantification combining LC-MS/MS and nSMOL proteolysis. It can be used for future clinical pharmacokinetic studies of belimumab and for investigating the relationship between belimumab concentration, efficacy, and toxicity in SLE patients.

Pre-COVID-19 Immunity to Common Cold Human Coronaviruses Induces a Recall-Type IgG Response to SARS-CoV-2 Antigens Without Cross-Neutralisation

The capacity of pre-existing immunity to human common coronaviruses (HCoV) to cross-protect against de novo COVID-19is yet unknown. In this work, we studied the sera of 175 COVID-19 patients, 76 healthy donors and 3 intravenous immunoglobulins (IVIG) batches. We found that most COVID-19 patients developed anti-SARS-CoV-2 IgG antibodies before IgM. Moreover, the capacity of their IgGs to react to beta-HCoV, was present in the early sera of most patients before the appearance of anti-SARS-CoV-2 IgG. This implied that a recall-type antibody response was generated. In comparison, the patients that mounted an anti-SARS-COV2 IgM response, prior to IgG responses had lower titres of anti-beta-HCoV IgG antibodies. This indicated that pre-existing immunity to beta-HCoV was conducive to the generation of memory type responses to SARS-COV-2. Finally, we also found that pre-COVID-19-era sera and IVIG cross-reacted with SARS-CoV-2 antigens without neutralising SARS-CoV-2 infectivity in vitro. Put together, these results indicate that whilst pre-existing immunity to HCoV is responsible for recall-type IgG responses to SARS-CoV-2, it does not lead to cross-protection against COVID-19.

Safety and effectiveness of transjugular renal biopsy for systemic lupus erythematosus and antiphospholipid antibody syndrome patients taking antithrombotics

BACKGROUND

Renal biopsy is the cornerstone of systemic lupus erythematosus (SLE) nephritis and antiphospholipid syndrome (APS) nephropathy management. However, transcutaneous renal biopsy (TCRB) is hampered by the antithrombotic treatment frequently prescribed for those diseases. Transjugular renal biopsy (TJRB) offers an attractive alternative for patients at increased risk of bleeding. The primary objective of the study was to describe the safety profile and diagnostic performance of TJRB in SLE and APS patients.

METHODS

All SLE and/or APS patients who underwent a renal biopsy in our department (between January 2004 and October 2016) were retrospectively reviewed. Major complications were death, haemostasis nephrectomy, renal artery embolization, red blood cell transfusion, sepsis and vascular thrombosis; macroscopic haematuria, symptomatic perirenal/retroperitoneal bleeding and renal arteriovenous fistula without artery embolization were considered as minor complications.

RESULTS

Two hundred and fifty-six TJRBs-119 without antithrombotics (untreated), 69 under aspirin and 68 on anticoagulants and 54 TCRBs without antithrombotics-were analysed. Their major and minor complication rates, respectively, did not differ significantly for the four groups: 0 and 8% for untreated TJRBs, 1 and 6% for aspirin-treated, 6 and 10% for anticoagulant-treated and 2 and 2% for TCRBs. The number of glomeruli sampled and the biopsy contribution to establishing a histological diagnosis was similar for the four groups.

CONCLUSIONS

TJRBs obtained from SLE and APS patients taking antithrombotics had diagnostic yields and safety profiles similar to those of untreated TCRBs. Thus, TJRB should be considered for SLE and APS patients at risk of bleeding.

P4169The crucial role of the bystander in out-of-hospital cardiac arrest resuscitation

Background

Out-of-hospital cardiac arrest (OHCA) is a major public health concern in France, given that there are 61.5 cases per 100,000 inhabitants a year. The impact of bystander action, performed before the arrival of emergency medical services (EMS), on survival has never been studied in France.

Purpose

Determine whether bystander cardiopulmonary resuscitation (CPR), performed before the arrival of EMS, was correlated with an increased 30-day survival rate after an OHCA.

Methods

24,885 out-of-hospital cardiac arrests witnessed in France from 1 January 2012 to 1 May 2018 were analysed to determine whether CPR, performed before the arrival of EMS, was correlated with survival. Data from the Electronic Registry of Cardiac Arrests was used. The association between the effect of CPR performed before the arrival of EMS and 30-day survival rate was studied, using propensity analysis (which included variables such as age and sex of the patient, location, cause, and year of cardiac arrest, initial cardiac rhythm, EMS response time and no-flow time).

Results

CPR was performed before the arrival of EMS in 14,904 cases (59.9%) and was not performed in 9,981 cases (40.1%). The 30-day survival rate was 10.2% when CRP was performed by bystanders versus 3.9% when CRP was not performed before the EMS arrival (p<0.001). CPR performed by bystanders was associated with an increased 30-day survival rate (odds ratio 1.269; 1.207 to 1.334).

The effect of bystander CPR on survival

Conclusion

Bystander CPR performed before the arrival of EMS was associated with an increased 30-day survival rate after an out-of-hospital cardiac arrest in France.

Rituximab-associated Vasculitis Flare: Incidence, Predictors, and Outcome

OBJECTIVE

To report the incidence, predictors, and outcome of rituximab (RTX)-associated autoimmune disease flare.

METHODS

We conducted a retrospective study in a tertiary referral center from 2005 to 2015. Disease flare was defined as the onset of a new organ involvement or worsening of autoimmune disease within 4 weeks following RTX.

RESULTS

Among the 185 patients, we identified 7 disease flares (3.4%). All were due to type II mixed cryoglobulinemia vasculitis. Vasculitis flare occurred after a median time of 8 days (range 2-16) following RTX infusion and included acute kidney insufficiency (n = 7), purpura with cutaneous (n = 7), gastrointestinal (GI) tract involvement (n = 4), and myocarditis (n = 1). Patients with RTX-associated cryoglobulinemia vasculitis flare had these conditions more frequently: renal involvement (p = 0.0008), B cell lymphoproliferation (p = 0.015), higher level of cryoglobulin (2.1 vs 0.4 g/l, p = 0.0004), and lower level of C4 (0.02 vs 0.05, p = 0.023) compared to patients without flare after RTX (n = 43). Four patients (57%) died after a median time of 3.3 months. The 1-year survival rate was poorer in patients with vasculitis flare after RTX compared to their negative counterpart [43% (95% CI 18-100) vs 97% (95% CI 92-100), p < 0.001]. Immunofluorescence analysis of kidney biopsy in patients with worsening RTX-associated vasculitis highlighted the presence of RTX-, IgM-, and IgG1-positive staining of endomembranous deposits and thrombi within kidney lesions.

CONCLUSION

RTX-associated cryoglobulinemia vasculitis flare is associated with high mortality rate. We provided evidence that kidney lesions are due to immune complex deposition and to glomerular obstruction by cryoglobulinemia and RTX.

Infliximab biosimilar for treating neurosarcoidosis: tolerance and efficacy in a retrospective study including switch from the originator and initiation of treatment

OBJECTIVES

Infliximab is increasingly used to treat neurosarcoidosis. We aimed to determine the efficacy and tolerance of an infliximab biosimilar for treating neurosarcoidosis.

METHODS

We conducted a retrospective single-center study to describe the efficacy, safety and immunogenicity of an infliximab biosimilar in neurosarcoidosis patients. We compared the survival time without relapse while receiving the biosimilar or previous originator-infliximab treatment.

RESULTS

Twenty patients with histologically documented neurosarcoidosis were treated with an infliximab biosimilar (initiation of treatment in 12 and switch from the originator drug in 8) between February 2016 and August 2018. All patients presenting with neurological involvement of one or more areas, including meningeal (n = 15), cerebral (n = 10), spinal cord (n = 9), and/or cranial nerves (n = 5); epilepsy (n = 3); and/or intracranial hypertension (n = 3) were enrolled. Eighteen patients received glucocorticoids during infliximab treatment, and 16 had methotrexate or azathioprine concomitant treatment. The median duration of follow-up was 25 months (19-28). Six patients relapsed during biosimilar treatment. Relapse rates and time-to-relapse did not differ between the infliximab originator previously received and biosimilar treatment groups (p = 0.40 and 0.51, respectively). Nine patients experienced 11 adverse events with the infliximab biosimilar, including infections (n = 5), urticaria (n = 4), headache (n = 1), and diarrhea (n = 1). All side effects were grade 2 or less using the WHO classification.

CONCLUSIONS

In this retrospective study, the infliximab biosimilar was efficacious and safe for treating neurosarcoidosis.

An attempt to study (111) oriented NiO-like TCO thin films in terms of structural, optical properties and photocatalytic activities under strontium doping

This work covers some physical properties of Sr-doped NiO sprayed thin films at various concentrations (0 to 4%) prepared on glass substrates. Structural properties by using X-ray diffraction (XRD) show that all films have a cubic structure with (111) orientation. The stress, estimated by adjusting the XRD diffraction peaks increases with the doping concentration. Also, the grain size decreases with the doping concentration. On the other hand, the stacking fault probability has been discussed in terms of Sr doping level. The surface morphology of NiO:Sr thin films were examined by AFM observations. The optical constants (refractive index and extinction coefficient) were obtained by reflectance and transmittance measurements. This optical measurements show that the optical band gap is around 3.8 eV. PL measurements show mainly the transition band in UV blue and green domains related to the band-to-band transition and some defects in these prepared thin films. Finally, the advances in the actively studied photocatalysts that are emerging as effective alternate for nickel oxide based photocatalysts is also discussed.

[Use of semi-automatic defibrillators outside the hospital]

With an annual incidence of 1 to 2@1000 and a rate of survival without complication of 2%, sudden death outside hospital constitutes a serious public health problem in France. Ventricular fibrillation (VF) is responsible for more than three quarters of these deaths. The rate of survival is inversely proportional to the duration of VF making early defibrillation a strong link in the chain of survival. The chances of survival are much greater if the cardio-respiratory arrest occurs with a witness, basic first aid is started rapidly, diagnosis of VF is made quickly and the first shock is delivered as soon as possible. These last two criteria are being met more often since the advent of the semi-automatic defibrillator (SAD) and its availability to first line rescuers. The SAD is a light and compact defibrillator capable of automatic analysis of the electrocardiographic trace, charging if it detects ventricular tachycardia (VT) or VF. By analysing the QRS amplitude, its slope, its morphology, its spectral density and the duration of the isoelectric line, the SAD is capable of recognising VF with a sensibility of 98% and a specificity of 93%. The shock, however, is only delivered with a manoeuvre from the operator. The SAD memorizes both the rhythmic event treated and certain parameters relating to its use. During the last decade, the SAD has benefited from the technological evolutions of the implantable automatic defibrillator, with the introduction of a biphasic shock. The use of a biphasic shock allows reduction in the minimal defibrillation charge and thus lightens the apparatus and increases the number of shocks which the SAD can deliver on a charged battery. In authorizing paramedics by statute to use the SAD, it has been possible to reduce the interval from alert to first delivered shock to 8 minutes although it would be 10 minutes if the medical team was awaited, and to obtain a survival rate without complication of 6.3%. The progress achieved by the use of the SAD in the chain of survival cannot be denied. However, to surpass automatic defibrillation and widen the use of defibrillators to an informed and motivated public would certainly bring our results closer to those obtained in America where the survival rate reaches 30% in the best cases; subject to widespread first aid training for the population.