Omalizumab in the treatment of bullous pemphigoid resistant to first-line therapy: a French national multicentre retrospective study of 100 patients.

BACKGROUND: Interest in the use of omalizumab to treat bullous pemphigoid (BP) in the event of resistance or contraindication to conventional therapies is currently based on limited evidence. OBJECTIVES: To assess the effectiveness and safety of omalizumab in BP and to identify predictive factors in response to treatment. METHODS: We conducted a French national multicentre retrospective study including patients with a confirmed diagnosis of BP treated with omalizumab after failure of one or several treatment lines. We excluded patients with clinically atypical BP, as per Vaillant's criteria. The criteria for clinical response to omalizumab were defined according to the 2012 international consensus conference. Anti-BP180-NC16A IgE enzyme-linked immunosorbent assay was performed on sera collected before initiating omalizumab, when available. RESULTS: Between 2014 and 2021, 100 patients treated in 18 expert departments were included. Median age at diagnosis was 77 years (range 20-98). Complete remission (CR) was achieved in 77% of patients, and partial remission in an additional 9%. CR was maintained 'off therapy' in 11.7%, 'on minimal therapy' in 57.1%, and 'on non-minimal therapy' in 31.2%. Median time to CR was 3 months (range 2.2-24.5). Relapse rate was 14%, with a median follow-up time of 12 months (range 6-73). Adverse events occurred in four patients. CR was more frequently observed in patients with an increased serum baseline level of anti-BP180-NC16A IgE (75% vs. 41%; P = 0.011). Conversely, urticarial lesions, blood total IgE concentration or eosinophil count were not predictive of CR. Patients with an omalizumab dosage > 300 mg every 4 weeks showed a similar final outcome to those with a dosage ≤ 300 mg every 4 weeks, but control of disease activity [median 10 days (range 5-30) vs. 15 days (range 10-60); P < 0.001] and CR [median 2.4 months (range 2.2-8.2) vs. 3.9 months (range 2.3-24.5); P < 0.001] were achieved significantly faster. CONCLUSIONS: We report the largest series to date of BP treated by omalizumab and confirm its effectiveness and safety in this indication. Serum baseline level of anti-BP180-NC16A IgE may predict response to treatment.

Molecular allergology: a clinical laboratory tool for precision diagnosis, stratification and follow-up of allergic patients.

Identification of the molecular culprits of allergic reactions leveraged molecular allergology applications in clinical laboratory medicine. Molecular allergology shifted the focus from complex, heterogeneous allergenic extracts, e.g. pollen, food, or insect venom, towards genetically and immunologically defined proteins available for in vitro diagnosis. Molecular allergology is a precision medicine approach for the diagnosis, stratification, therapeutic management, follow-up and prognostic evaluation of patients within a large range of allergic diseases. Exclusively available for in vitro diagnosis, molecular allergology is nonredundant with any of the current clinical tools for allergy investigation. As an example of a major application, discrimination of genuine sensitization from allergen cross-reactivity at the molecular level allows the proper targeting of the culprit allergen and thus dramatically improves patient management. This review aims at introducing clinical laboratory specialists to molecular allergology, from the biochemical and genetic bases, through immunological concepts, to daily use in the diagnosis and management of allergic diseases.

Alveolar hemorrhage due to marijuana smoking using water pipe made with plastic bottle: case report and narrative review of the literature.

INTRODUCTION: We described a case of alveolar hemorrhage (AH) after marijuana smoking using a water pipe made with plastic bottle (bong) before making a narrative review of the literature. CASE REPORT: A 19-year-old male was admitted for hemoptysis and dyspnea evolving since the previous day. He smoked marijuana ten times a day using bongs. Computed tomography scan of the chest (chest CT-scan) evidenced ground glass opacities involving upper lobes with crazy-paving pattern. Bronchoalveolar lavage (BAL) yielded fluid becoming progressively bloody suggestive of AH. Screening of drug metabolites ruled out the presence of cocaine degradation products. Treatment with prednisone was prescribed and oxygen requirements decreased rapidly. The patient accepted to stop bongs, but kept on smoking marijuana using joints. He was asymptomatic 2 months later; all ground glass opacities had vanished. REVIEW OF THE LITERATURE: Four cases described exactly the same circumstances as ours. All were young male patients containing ground glass opacities with diffuse or bilateral pattern in their chest CT-scan. The explanation suggested by the authors of these cases was the potential concomitant inhalation of acid anhydrides derived from use of heated plastic bottle. No acid anhydrides were experimentally evidenced after thermodesorption of heated polyethylene terephthalate (PET) (in which a majority of plastic bottles are made) we performed, but other compounds were. E-cigarette, or vaping, product use-associated lung injuries cases share some chest CT-scan patterns with those of AH following bong use and we tried to draw a parallel between these two latter before discussing a physiopathological hypothesis.

Biomarkers related to bullous pemphigoid activity and outcome.

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease of the skin. Investigation of the BP-associated pathophysiological processes during the last decades showed that the generation of autoantibodies directed against the hemidesmosome proteins BP180 and BP230, a hallmark of the BP-associated autoimmune response, leads to the recruitment of inflammatory immune cells at the dermal-epidermal junction, and subsequently to the release of a large amount of inflammatory molecules involved in blister formation. Analysis in transversal and longitudinal studies of autoantibodies and inflammatory molecules production both at the time of diagnosis and under treatment was mainly performed within the serum but also in the blister fluid. Some autoimmune or inflammatory molecules expression was related to the presence of clinical signs, while others were mere bystanders. In this review, we focused on the autoimmune and inflammatory molecules that have been identified as potential biomarkers of BP development and outcome.

Characterization of the novel HLA-B*15:648 allele by next-generation sequencing.

HLA-B*15:648 differs from HLA-B*15:02:01:01 by one nucleotide substitution in codon 77 in exon 2.

Characterisation of the novel HLA-DQA1*04:14N allele by next-generation sequencing.

HLA-DQA1*04:14N differs from HLA-DQA1*04:01:01:03 by a single nucleotide deletion in codon 113 in exon 3.

Virus detection and semiquantitation in explanted heart tissues of idiopathic dilated cardiomyopathy adult patients by use of PCR coupled with mass spectrometry analysis.

Viral detection in heart tissues has become a central issue for the diagnosis and exploration of the pathogenesis of idiopathic dilated cardiomyopathy (IDCM). In the present study, common cardiotropic viruses in 67 explanted heart samples of 31 IDCM adult patients were detected and semiquantified by using for the first time a new technology based on PCR assay coupled to electrospray ionization-time of flight mass spectrometry analysis (PCR-MS), with comparison to reference quantitative real-time PCR (RT-qPCR) assay. PCR-MS identified single or mixed enterovirus (EV) and parvovirus B19 (PVB19) infections in 27 (40.2%) of 67 samples, corresponding to 15 (48.3%) of the 31 patients, whereas RT-qPCR identified viral infections in 26 (38.8%) samples, corresponding to 16 (51.6%) of the patients. The PCR-MS results correlated well with EV and PVB19 detection by RT-qPCR (kappa = 0.85 [95% confidence interval {CI}, 0.72 to 1.00] and kappa = 0.82 [95% CI, 0.66 to 0.99], respectively). The levels of EV RNA (median, 550 [range, 178 to 3,200] copies/µg of total extracted nucleic acids) and of PVB19 DNA (median, 486 [range, 80 to 1,157] copies/µg of total extracted nucleic acids) were measured using PCR-MS and correlated with those obtained by RT-qPCR (r(2) = 0.57, P = 0.002 and r(2) = 0.64, P < 0.001 for EV and PVB19, respectively). No viruses other than EV and PVB19 strains were detected using the new PCR-MS technology, which is capable of simultaneously identifying 84 known human viruses in one assay. In conclusion, we identified single or mixed EV and PVB19 cardiac infections as potential causes of IDCM. The PCR-MS analysis appeared to be a valuable tool to rapidly detect and semiquantify common viruses in cardiac tissues and may be of major interest to better understand the role of viruses in unexplained cardiomyopathies.

Virological diagnosis and management of two cases of congenital measles.

Measles is a highly contagious viral infection causing congenital infections with a risk of neurological complications in the newborn. Two cases of measles, which occurred in pregnant women within 14 days before the delivery, are described. Mother-to-child transmission of the virus was documented in the newborns either by RT-PCR in saliva or by IgM detection in blood. The measles strains evidenced in saliva samples were genotyped and belonged to the D4 Genotype. An early viral RT-PCR detection allowed successful immunoglobulin prophylaxis in one newborn taking into account that the duration between the onset of the skin rash in the mother and the delivery was less than 6 days. Twenty-four months later, none of the newborns developed classical or neurological clinical signs of measles infection. Measles RT-PCR assay in salivary samples can be used before symptoms develop in the infant to confirm early mother-to-child transmission, therefore permitting the use of an immunoglobulin prophylaxis in the newborn.

Characterization of the novel HLA-A*01:383 allele by next-generation sequencing.

HLA-A*01:383 differs from HLA-A*01:01:01:01 by two nucleotide substitutions at positions 28 and 48 in exon 1.

Characterization of the novel HLA-A*33:220 allele by next-generation sequencing.

HLA-A*33:220 differs from HLA-A*33:03:01:01 by one nucleotide substitution in codon 245 in exon 4.

Characterization of the novel HLA-C*07:1001N allele by next-generation sequencing.

HLA-C*07:1001N differs from HLA-C*07:01:01:01 by a deletion of 17 nucleotides in exon 1.

Characterization of the novel HLA-C*16:184 allele by next-generation sequencing.

HLA-C*16:184 differs from HLA-C*16:02:01:01 by one nucleotide substitution at position 737 in exon 3.

Characterization of the novel HLA-C*03:04:94 allele by next-generation sequencing.

HLA-C*03:04:94 differs from HLA-C*03:04:01:01 by one nucleotide substitution at position 737 in exon 4.

Characterization of the novel HLA-C*05:255 allele by next-generation sequencing.

HLA-C*05:255 differs from HLA-C*05:01:01:02 by one nucleotide substitution at position 2013 in exon 5.

Characterization of the novel HLA-B*53:64 allele by next-generation sequencing.

HLA-B*53:64 differs from HLA-B*53:01:01:01 by one nucleotide substitution at position 1617 in exon 4.

Characterization of the novel HLA-C*06:317 allele by next-generation sequencing.

HLA-C*06:317 differs from HLA-C*06:02:01:01 by one nucleotide substitution at position 921 in exon 3.

External Evaluation of Population Pharmacokinetic Models and Bayes-Based Dosing of Infliximab.

Despite the well-demonstrated efficacy of infliximab in inflammatory diseases, treatment failure remains frequent. Dose adjustment using Bayesian methods has shown in silico its interest in achieving target plasma concentrations. However, most of the published models have not been fully validated in accordance with the recommendations. This study aimed to submit these models to an external evaluation and verify their predictive capabilities. Eight models were selected for external evaluation, carried out on an independent database (409 concentrations from 157 patients). Each model was evaluated based on the following parameters: goodness-of-fit (comparison of predictions to observations), residual error model (population weighted residuals (PWRES), individual weighted residuals (IWRES), and normalized prediction distribution errors (NPDE)), and predictive performances (prediction-corrected visual predictive checks (pcVPC) and Bayesian simulations). The performances observed during this external evaluation varied greatly from one model to another. The eight evaluated models showed a significant bias in population predictions (from -7.19 to 7.38 mg/L). Individual predictions showed acceptable bias and precision for six of the eight models (mean error of -0.74 to -0.29 mg/L and mean percent error of -16.6 to -0.4%). Analysis of NPDE and pcVPC confirmed these results and revealed a problem with the inclusion of several covariates (weight, concomitant immunomodulatory treatment, presence of anti-drug antibodies). This external evaluation showed satisfactory results for some models, notably models A and B, and highlighted several prospects for improving the pharmacokinetic models of infliximab for clinical-biological application.

The 13-Valent Pneumococcal Conjugate Vaccine Elicits Serological Response and Lasting Protection in Selected Patients With Primary Humoral Immunodeficiency.

Background: Patients with primary humoral immunodeficiency are more prone to invasive as well as recurrent pneumococcal infections. Therefore, anti-pneumococcal vaccination including the 13-valent conjugate vaccine is recommended. Nevertheless, to date, no data is available on immunogenicity of this vaccine in this population. Objective: To assess the immunogenicity and the persistence of protection up to one year after a 13-valent pneumococcal conjugate vaccine in patients with primary humoral immunodeficiency. Methods: Twenty-nine patients with common variable immunodeficiency or IgG subclass deficiency were vaccinated. Immune response and immune protection at baseline as well as at one, six and twelve months after vaccination were evaluated by measuring specific IgG serum concentrations (ELISA), and opsonophagocytic activities directed against selected pneumococcal (MOPA). Results: By ELISA, half of the patients had protective IgG concentrations before vaccination, 35.7% showed an immune response one month after vaccination, 71.4%, 66.7% and 56.0% of the patients were protected at one, six and twelve months respectively. Conversely, by MOPA, 3.4% of the patients were protected at baseline, 10.7% showed an immune response and 28.6%, 48.2% and 33.3% were protected at one, six and twelve months respectively. IgG subclass deficiency, Ig replacement therapy and higher IgG2 concentrations at diagnosis were associated with long-term protection. Conclusion: Pneumococcal conjugate vaccine improves immune protection and antibodies' functionality in a subset of patients with primary immunodeficiency. Prime-boost vaccine strategy needs to be better and individually adapted.

Neutrophil Extracellular Traps Generation Relates with Early Stage and Vascular Complications in Systemic Sclerosis.

Systemic sclerosis (SSc) is a systemic disease characterized by a great clinical and immunological heterogeneity whose pathophysiology is still being unraveled. Recently, innate immunity has been proposed to participate to the pathogenesis of SSc. In this study, we investigated the release of neutrophil extracellular traps (NETs) according to patient phenotype. Polymorphonuclear neutrophils (PMN) from 34 SSc patients and 26 healthy controls were stimulated by serum from SSc or healthy subject. NETs were visualized using epifluorescence microscope after DNA, myeloperoxidase, and Histone H3 tagging. Area of NETs were quantified using an original macro running in ImageJ® software. PMN from SSc patients were significantly more prone to releasing NETs than control PMN after autologous stimulation. PMN from patients with severe vascular complications (pulmonary arterial hypertension, digital ulcers) produced more NETs than PMN from other SSc patients and their aberrant NET production appeared to be sustained over time. In patients with pulmonary interstitial disease or extensive cutaneous fibrosis, NET production was high at an early stage of the disease before progressively decreasing. Both serum factors and PMN activation status were involved in the enhanced production of NETs in SSc. Consequently, neutrophils and especially NETosis represent new physiopathological and therapeutic fields in SSc.