Impact of Calcineurin Inhibitor-Based Immunosuppression Maintenance During the Dialysis Period After Kidney Transplant Failure on the Next Kidney Graft Outcome: A Retrospective Multicenter Study With Propensity Score Analysis.

The impact of immunosuppressive therapy (IS) strategies after kidney transplant failure (KTF) on potential future new grafts is poorly established. We assessed the potential benefit of calcineurin inhibitor (CNI)-based IS maintenance throughout the dialysis period on the outcome of the second kidney transplant (KT). We identified 407 patients who underwent a second KT between January 2008 and December 2018 at four French KT centers. Inverse probability of treatment weighting was used to control for potential confounding. We included 205 patients with similar baseline characteristics at KTF: a total of 53 received at least CNIs on the retransplant day (G-CNI), and 152 did not receive any IS (G-STOP). On the retransplant date, G-STOP patients experienced a longer pretransplant dialysis time, were more often hyperimmunized, and underwent more expanded-criteria donor KTs than G-CNI patients. During the second KT follow-up period, rejection episodes were similar in both groups. The 10-year survival rates without death and dialysis were 98.7% and 59.5% in G-CNI and G-STOP patients, respectively. In the multivariable analysis, CNI-based IS maintenance was associated with better survival (hazard ratio: 0.08; 95% confidence interval: 0.01-0.58, p = 0.01). CNI-based IS maintenance throughout the dialysis period after KTF may improve retransplantation outcomes.

Droplet digital PCR allows vector copy number assessment and monitoring of experimental CAR T cells in murine xenograft models or approved CD19 CAR T cell-treated patients.

BACKGROUND: Genetically engineered chimeric antigen receptor (CAR) T lymphocytes are promising therapeutic tools for cancer. Four CAR T cell drugs, including tisagenlecleucel (tisa-cel) and axicabtagene-ciloleucel (axi-cel), all targeting CD19, are currently approved for treating B cell malignancies. Flow cytometry (FC) remains the standard for monitoring CAR T cells using a recombinant biotinylated target protein. Nevertheless, there is a need for additional tools, and the challenge is to develop an easy, relevant, highly sensitive, reproducible, and inexpensive detection method. Molecular tools can meet this need to specifically monitor long-term persistent CAR T cells. METHODS: Based on 2 experimental CAR T cell constructs, IL-1RAP and CS1, we designed 2 quantitative digital droplet (ddPCR) PCR assays. By targeting the 4.1BB/CD3z (28BBz) or 28/CD3z (28z) junction area, we demonstrated that PCR assays can be applied to approved CD19 CAR T drugs. Both 28z and 28BBz ddPCR assays allow determination of the average vector copy number (VCN) per cell. We confirmed that the VCN is dependent on the multiplicity of infection and verified that the VCN of our experimental or GMP-like IL-1RAP CAR T cells met the requirement (< 5 VCN/cell) for delivery to the clinical department, similar to approved axi-cel or tisa-cel drugs. RESULTS: 28BBz and 28z ddPCR assays applied to 2 tumoral (acute myeloid leukemia (AML) or multiple myeloma (MM) xenograft humanized NSG mouse models allowed us to quantify the early expansion (up to day 30) of CAR T cells after injection. Interestingly, following initial expansion, when circulating CAR T cells were challenged with the tumor, we noted a second expansion phase. Investigation of the bone marrow, spleen and lung showed that CAR T cells disseminated more within these tissues in mice previously injected with leukemic cell lines. Finally, circulating CAR T cell ddPCR monitoring of R/R acute lymphoid leukemia or diffuse large B cell lymphoma (n = 10 for tisa-cel and n = 7 for axi-cel) patients treated with both approved CAR T cells allowed detection of early expansion, which was highly correlated with FC, as well as long-term persistence (up to 450 days), while FC failed to detect these events. CONCLUSION: Overall, we designed and validated 2 ddPCR assays allowing routine or preclinical monitoring of early- and long-term circulating approved or experimental CAR T cells, including our own IL-1RAP CAR T cells, which will be evaluated in an upcoming phase I clinical trial.

Platelet transfusion refractoriness and anti-HLA immunization.

Platelet transfusion refractoriness (PTR), defined as an unsatisfactory post-transfusion platelet count increment, is a common complication of patients receiving multiple transfusions. Different strategies are described in the management of PTR. In this work, we demonstrate the efficacy of the detection and identification of anti-HLA antibodies in the recipient using a threshold of 3000 mean fluorescence intensity (MFI), and the seek of donors not expressing HLA antigens against which the patient is immunized.

Immune checkpoint inhibitors reverse tolerogenic mechanisms induced by melanoma targeted radionuclide therapy.

In line with the ongoing phase I trial (NCT03784625) dedicated to melanoma targeted radionuclide therapy (TRT), we explore the interplay between immune system and the melanin ligand [131I]ICF01012 alone or combined with immunotherapy (immune checkpoint inhibitors, ICI) in preclinical models. Here we demonstrate that [131I]ICF01012 induces immunogenic cell death, characterized by a significant increase in cell surface-exposed annexin A1 and calreticulin. Additionally, [131I]ICF01012 increases survival in immunocompetent mice, compared to immunocompromised (29 vs. 24 days, p = 0.0374). Flow cytometry and RT-qPCR analyses highlight that [131I]ICF01012 induces adaptive and innate immune cell recruitment in the tumor microenvironment. [131I]ICF01012 combination with ICIs (anti-CTLA-4, anti-PD-1, anti-PD-L1) has shown that tolerance is a main immune escape mechanism, whereas exhaustion is not present after TRT. Furthermore, [131I]ICF01012 and ICI combination has systematically resulted in a prolonged survival (p < 0.0001) compared to TRT alone. Specifically, [131I]ICF01012 + anti-CTLA-4 combination significantly increases survival compared to anti-CTLA-4 alone (41 vs. 26 days; p = 0.0011), without toxicity. This work represents the first global characterization of TRT-induced modifications of the antitumor immune response, demonstrating that tolerance is a main immune escape mechanism and that combining TRT and ICI is promising.

Preanalytical, analytical, gestational and pediatric aspects of the S100B immuno-assays.

BACKGROUND: Traumatic brain injury management is a tricky issue in children and pregnant women (due to adverse effects of computer tomography). To facilitate management, we report the main analytical performances and reference ranges for blood tests for the well-established S100B biomarker in under-16 children on a DiaSorin® Liaison XL analyzer and in pregnant women on DiaSorin® Liaison XL and Roche Diagnostics® Cobas e411 analyzers. METHODS: Serum S100B concentrations were determined by chemiluminescent immunoassay on a DiaSorin® analyzer in a population of 409 healthy children aged 0-16 years and on DiaSorin®/Roche Diagnostics® instruments in a population of 50 pregnant women (one blood sample for each trimester). The analytical performances of both instruments and the influence of blood cells and skin pigmentation on the assay were also studied. RESULTS: For children, four age-groups emerged, i.e. 0-3 months (mean: 0.97 µg/L; standard deviation (SD): 0.36; 95th percentile: 1.55), 4-9 months (mean: 0.58 µg/L; SD: 0.30; 95th: 1.18), 10-24 months (mean: 0.31 µg/L; SD: 0.12; 95th: 0.54) and 2-16 years (mean: 0.20 µg/L; SD: 0.07; 95th: 0.32). For pregnant women, serum S100B concentrations were similar to defined ranges for adults and not significantly different between trimesters on DiaSorin® (p=0.652)/Roche Diagnostics® (p=0.877) analyzers. We also found S100B expression (protein, total mRNA) in lymphocytes, an influence of skin pigmentation, and good analytical performances for both instruments. CONCLUSIONS: Data provided here is useful for interpreting serum S100B test results, in terms of preanalytical conditions, analytical performances, pediatric and pregnancy' environment.

The basophil activation test: a sensitive test in the diagnosis of allergic immediate hypersensitivity to pristinamycin.

Immediate hypersensitivity (IHS) reactions to macrolides and to macrolide-derived antibiotics like pristinamycin are uncommon. In this context, there is little data available to appreciate the true value of biological tools regarding the diagnosis of immediate allergy to pristinamycin. Here we assess the clinical usefulness of the basophil activation test (BAT) to differentiate allergic from nonallergic IHS to pristinamycin. Thirty-six patients were tested with skin tests as the gold standard and BAT. The BAT achieved a sensitivity of 76% and a specificity of 100%, implying an absence of false positive results. Multicenter studies remain to be performed to better define the sensitivity, specificity and interlaboratory variation of BAT in the diagnosis of allergy to pristinamycin and macrolides.

Adoptive T Cell Therapy in Solid Tumors: State-of-the Art, Current Challenges, and Upcoming Improvements.

In solid tumors, three main complementary approaches of adoptive T-cell therapies were successively developed: tumor-infiltrating lymphocytes, chimeric antigen receptor engineered T cells, and high-affinity T-cell receptor engineered T cells. In this review, we summarized rational and main results of these three adoptive T-cell therapies in solid tumors field and gave an overview of encouraging data and their limits. Then, we listed the major remaining challenges (including tumor antigen loss, on-target/off-tumor effect, tumor access difficulties and general/local immunosubversion) and their lines of research. Finally, we gave insight into the ongoing trials in solid tumor.

[Relapse with HLA loss after hematopoietic stem cell transplantation with non-HLA identical donor: Guidelines from the Francophone society of bone marrow transplantation and cellular therapy (SFGM-TC)]. / Perte d'hétérozygotie HLA dans les rechutes après greffes de cellules souches hématopoïétiques avec donneur non HLA identique : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

Loss of heterozygosity or HLA loss is a genomic-type escape mechanism highlighted in certain types of relapses after allogeneic hematopoietic stem cell transplantation with a non-HLA identical donor, and especially after haplo-identical transplantation. The diagnosis must be made with certainty because the result conditions the therapy. In this article, the different mechanisms and techniques that can be used for the diagnosis of loss of heterozygosity, as well as the therapeutic options are reviewed, making it possible to establish clinico-biological recommendations for the diagnosis confirmation and management of the patients in relapse.

Characterization of the novel HLA-C*16:98:02 allele by sequencing-based typing.

HLA-C*16:98:02 differs from HLA-C*16:98:01 by one nucleotide substitution in codon 132 in exon 3.

Characterization of the novel HLA-DRB1*13:03:13 allele by sequencing-based typing.

HLA-DRB1*13:03:13 differs from HLA-DRB1*13:03:01:01 by one nucleotide substitution in codon 180 in exon 3.

Characterization of the novel HLA-B*39:06:09 allele by sequencing-based typing.

HLA-B*39:06:09 differs from HLA-B*39:06:02:01 by one nucleotide substitution in codon 135 in exon 3.

Characterization of the novel HLA-DPA1*01:03:51 allele by sequencing-based typing.

HLA-DPA1*01:03:51 differs from HLA-DPA1*01:03:01:01 by one nucleotide substitution in codon 146 in exon 3.

Characterization of the novel HLA-DRB1*11:324 allele by sequencing-based typing.

HLA-DRB1*11:324 differs from HLA-DRB1*11:62:02 by one nucleotide substitution in codon 38 in exon 2.

Characterization of the novel HLA-B*08:312 allele by sequencing-based typing.

HLA-B*08:312 differs from HLA-B*08:01:01:01 by one nucleotide substitution in codon 324 in exon 6.

Characterisation of the novel HLA-DRB1*04:379N allele by sequencing-based typing.

HLA-DRB1*04:379N differs from HLA-DRB1*04:01:01:01 by one nucleotide substitution in codon 4 in exon 1.

Characterisation of the novel HLA-DQA1*05:112 allele by sequencing-based typing.

HLA-DQA1*05:112 differs from HLA-DQA1*05:05:01:01 by one nucleotide substitution in codon -7 in exon 1.

Characterisation of the novel HLA-DRB4*01:182 allele by sequencing-based typing.

HLA-DRB4*01:182 differs from HLA-DRB4*01:03:01:01 by one nucleotide substitution in codon 172 in exon 3.

Characterization of the novel HLA-DQB1*02:01:01:21Q allele by sequencing-based typing.

HLA-DQB1*02:01:01:21Q differs from HLA-DQB1*02:01:01:01 by one nucleotide substitution in the splice site in the beginning of intron 3.

Characterization of the novel HLA-DPA1*02:122 allele by sequencing-based typing.

HLA-DPA1*02:122 differs from HLA-DPA1*02:01:01:02 by one nucleotide substitution in codon 78 in exon 2.