Wang, Wei

Abstract Background Despite advances in clinical microbiology, the diagnosis of invasive fungal infections remains challenging. Giant magnetoresistance (GMR) is a novel technology that enables the detection of trace amounts of cell-free DNA (cfDNA). We evaluated a high-multiplex molecular diagnostic assay coupled with GMR-enabled lab-on-a-chip technology that can detect 18 different fungal species. Methods Analytical performance was evaluated in spiked plasma samples. After amplification, cfDNA was digested. Residual single-stranded DNA was flowed over a GMR sensor that was surface-coated with probes specific to different fungal species. After hybridization, magnetic beads bound to the probe complexes produced a GMR signal that was detected by the sensors. Clinical performance was determined using residual serum samples collected before the initiation of antifungal treatment from 20 patients with infection. Results The limit of detection of the assay ranged from 5 to 50 copies per polymerase chain reaction (PCR) reaction. Nonspecific signals were not observed in the spiked samples. Fungal cfDNA was detected in 80% of patients with invasive candidiasis (3/4 with candidemia, 5/6 with invasive candidiasis without candidemia), all 3 cases of invasive pulmonary aspergillosis, and all 3 cases of disseminated histoplasmosis. cfDNA was not detected in 2 patients with cryptococcosis (both had negative blood cultures) and 2 patients with Pneumocystis pneumonia. Conclusions We developed a novel GMR-enabled multiplex PCR assay detecting fungal pathogens that have been prioritized for public health action. Clinical sensitivity was highest in cases of presumed angioinvasion and dissemination. This technology has the potential for use in the clinical microbiology laboratory setting.

Background : Rituximab is a monoclonal antibody that targets CD20 and can significantly improve the prognosis of patients with CD20-positive B-cell non-Hodgkin lymphoma (B-NHL). Nonetheless, a significant number of patients experience disease progression or relapse post-rituximab therapy. CD19-chimeric antigen receptor (CAR) T cells have demonstrated remarkable efficacy in B-NHL treatment. However, few studies have focused on the efficacy and safety of CD20 CAR-T cells in rituximab-refractory/relapsed (R/R) B-NHL patients, particularly those treated with rituximab for a short time. Here, we conducted a prospective study, aimed to assess the long-term remission and survival in patients with rituximab-R/R B-NHL after treatment with U16 (CD20 CAR-T cells). Methods : This first-in-human study is an open-label, single center investigator-initiated trial (IIT) to determine the safety and efficacy of CD20 CAR-T in R/R B-NHL after previous rituximab treatment failure (no. ChiCTR2000036350). CD20 CAR-T was administered at a target dose of 1.0×107 CAR-T cells/kg after a 3-day conditioning chemotherapy with fludarabine and cyclophosphamide. The primary objective was to assess the safety and tolerability of CD20 CAR-T. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were graded according to ASTCT 2019 criteria. The secondary objectives were to evaluate efficacy and pharmacokinetics (PK). Response was assessed per Lugano 2014 criteria. Results:A total of 16 patients with R/R B-NHL were enrolled.The median age was 49 years (range, 28-66). Median number of prior lines of therapy was 3 (range, 2-5). All patients had received rituximab therapy; of these, 9 had done so within the 3 months before CAR-T infusion. CRS occurred in all patients, with 11 patients (68.75%) experiencing grade 1 or 2 CRS and 5 patients (31.25%) experiencing grade 3 CRS. No patient developed grade 4 CRS , and only one patient had ICANS.The most common grade 3 or higher adverse events observed after infusion included leukopenia (93.3%), anemia (40%) and thrombocytopenia (60%). An overall response rate of 100% was observed among enrolled patients, with 11 patients (68.75%) achieving complete remission(CR) and 5 patients (32.25%) achieving partial remission(PR) within 3 months. The median follow-up time was 11.7 months(range 0.69-47.47). The median overall survival was not reached, and the median progression-free survival was 14.5 months. 9 patients remained CR or PR for 12 months, with 7 of them continuing in CR for up to 24 months. The pharmacokinetics of CD20 CAR-T cells were assessed using quantitative PCR to determine the expansion and persistence ability. Peak CAR amplification were detected 7-14 days after infusin. Patients 1, 2 and 4 achieved long-term remission, and persistent positive CAR-T cell copy numbers were detected for 15 months, 30 months and 26 months, respectively. However, patients 7, 8 and 12 relapsed within 3 months, and the CAR-T cell copies of all three patients were reduced to fewer than 1×103 copies/μg of DNA within 3 months. The qPCR results indicated that the maintenance of efficacy was closely related to the persistence of CAR-T cells. Notably, patients who received rituximab less than 3 months before CAR-T infusion had a poorer prognosis, with higher relapse rates (77.8% vs. 28.6%) and shorter progression-free survival, regardless of the degree of response. Conclusion : Long-term follow-up demonstrated that CD20 CAR-T therapy can produce a deep and durable response with a favorable safety profile in patients with rituximab-refractory/relapsed B-NHL. Notably, patients who had received rituximab within 3 months had a poorer prognosis.