Limitations of biopsy-based transcript diagnostics to detect T cell-mediated allograft rejection.

BACKGROUND AND HYPOTHESIS: Isolated Tubulitis, Borderline Changes, and Isolated Arteritis suspicious for histologic T cell-mediated rejection (hTCMR) remain findings of uncertain significance. Although the Molecular Microscope Diagnostics System (MMDx) has not been trained on those lesions, it was suggested that MMDx might reclassify a subgroup to molecular TCMR (mTCMR). METHODS: In this single-center cohort of 326 consecutive, unselected kidney allograft biopsies assessed by histology and MMDx, we analyzed 249 cases with Isolated Tubulitis (i0, t1-3, v0; n=101), Borderline Changes (according to Banff 2022, v0; n=9), Isolated Arteritis (no borderline, v1; n=37), No Inflammation (i0, t0, v0; n=67) and a Positive Control Cohort (hTCMR, n=27; Mixed histologic Rejection, n=8; both according to Banff 2022; total n=35). The first three groups were summarized as TCMR-Suspicion (n=147). Subcategorization included the presence and absence of microvascular inflammation (MVI; g+ptc≥2). Molecular rejection rates and differentiation were investigated. RESULTS: Molecular rejection rates were 37/147 cases (25.2%; 32 with MVI) in TCMR-Suspicion, 6/67 (9%; 4 with MVI) in No Inflammation and 30/35 (85.7%; 19 with MVI) in the Positive Control Cohort. Molecular antibody-mediated rejection (mAMR) was present in 39/73 (53.4%) of cases. The presence of donor-specific antibodies (DSA) at the time of the biopsy was high (127/249, 51%). Only 3 mAMR/TCMR and no pure mTCMR cases were detected in TCMR-Suspicion and No Inflammation, compared to 12 mAMR/TCMR and 10 mTCMR cases in the Positive Control Cohort (p<0.001). Even though the TCMR-specific molecular (Classifier) score differentiated between TCMR-Suspicion and No Inflammation (p=0.005), rejection phenotype scores (R2 and R3) did not (p=0.157 and 0.121). CONCLUSIONS: MMDx did not identify pure mTCMR among Isolated Tubulitis, Borderline Changes, or Isolated Arteritis, likely due to low sensitivity for TCMR-lesions. However, it identified mAMR or mAMR/TCMR, especially in cases with MVI. Subthreshold findings remain to be further studied.

Molecular diagnosis of antibody-mediated rejection: Evaluating biopsy-based transcript diagnostics in the presence of donor-specific antibodies but without microvascular inflammation, a single-center descriptive analysis.

Biopsy-based transcript diagnostics may identify molecular antibody-mediated rejection (AMR) when microvascular inflammation (MVI) is absent. In this single-center cohort, biopsy-based transcript diagnostics were validated in 326 kidney allograft biopsies. A total of 71 histological AMR and 35 T cell-mediated rejection (TCMR) cases were identified as molecular AMR and TCMR in 55% and 63%, respectively. Among 121 cases without MVI (glomerulitis + peritubular capillaritis = 0), 45 (37%) donor-specific antibody (DSA)-positive and 76 (63%) DSA-negative cases were analyzed. Twenty-one out of the 121 (17%) cases showed borderline changes, or TCMR, while BK nephropathy was excluded. None of the 45 DSA-positive patients showed molecular AMR. Among 76 DSA-negative patients, 2 had mixed molecular AMR/TCMR. All-AMR phenotype scores (sum of R4-R6) exhibited median values of 0.13 and 0.12 for DSA-positive and DSA-negative patients, respectively (P = .84). A total of 13% (6/45) DSA-positive and 11% (8/76) DSA-negative patients showed an all-AMR phenotype score > 0.30 (P = .77). Patients with a higher all-AMR phenotype score showed 33% more histologic TCMR (P = .005). The median all-AMR phenotype scores of glomerular basement membrane double contours = 0 and glomerular basement membrane double contours > 0 biopsies were 0.12 and 0.10, respectively (P = .35). Biopsy-based transcript diagnostics did not identify molecular AMR in cases without MVI. Follow-up biopsies and outcome data should evaluate the clinical relevance of subthreshold molecular alterations.

Clinical spectrum of gross haematuria following SARS-CoV-2 vaccination with mRNA vaccines.

Background: Novel messenger RNA (mRNA)-based vaccines play an important role in current vaccination campaigns against SARS-CoV-2. They are highly efficacious and generally well tolerated. Vaccination in patients with immune-mediated kidney diseases is recommended. A number of cases with de novo or relapsing glomerulonephritis shortly after vaccine application have been reported, some of which presented with gross haematuria. Methods: We collected 10 cases of macrohaematuria following mRNA-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination at our tertiary care institution and referring centres. Additionally, we pooled all 25 published cases from the literature with ours to analyse their clinical characteristics. Results: Most macrohaematuria episodes (72.2%) began within 2 days after vaccination, the majority after the second dose. In some individuals, repeated episodes occurred after subsequent doses of the same vaccine. A total of 65.7% of patients never had macrohaematuria before. A total of 45.7% were known to suffer from immunoglobulin A nephropathy (IgAN); the rest had no prior renal diagnosis. IgAN was the most frequent new diagnosis, but anti-neutrophil cytoplasmic antibody-associated vasculitis and anti-glomerular basement membrane disease were also identified. Acute kidney injury (AKI) occurred in 28.6% of patients, with an increase in serum creatinine not meeting Kidney Disease: Improving Global Outcomes AKI criteria in 28.6%. Treatment ranged from conservative management, renin-angiotensin-aldosterone system inhibitors, steroids and cyclophosphamide to plasmapheresis. While renal outcomes were mainly favourable in isolated IgAN, they were poor in patients with additional or isolated small vessel vasculitis. Conclusion: Awareness of gross haematuria after SARS-CoV-2 vaccination is important. Close follow-up and additional work up, particularly in individuals without known underlying kidney disease or worsening renal function, is essential. For patients with vaccine-associated macrohaematuria, an alternative vaccine class might be considered for subsequent vaccinations.

Automatic classification of signal regions in 1H Nuclear Magnetic Resonance spectra.

The identification and characterization of signal regions in Nuclear Magnetic Resonance (NMR) spectra is a challenging but crucial phase in the analysis and determination of complex chemical compounds. Here, we present a novel supervised deep learning approach to perform automatic detection and classification of multiplets in 1H NMR spectra. Our deep neural network was trained on a large number of synthetic spectra, with complete control over the features represented in the samples. We show that our model can detect signal regions effectively and minimize classification errors between different types of resonance patterns. We demonstrate that the network generalizes remarkably well on real experimental 1H NMR spectra.

Governing complex societal problems: The impact of private on public regulation through technological change.

When addressing complex societal problems, public regulation is increasingly complemented by private regulation. Extant literature has provided valuable insights into the effectiveness of such complex governance structures, with most empirical studies focusing on how public regulation influences private regulation. Conversely, the impact of private on public regulation is less well studied. Here, we investigate this impact with a focus on technological change as possible mechanism. Based on a case study of energy efficiency in buildings in Switzerland, we find evidence of a symbiotic interaction between public and private regulation that leads to ratcheting-up of regulatory stringency. We identify technological change as the mechanism linking private and public regulation. We discuss the relevance of our findings for governance literature and regulators.

Cystatin F is a biomarker of prion pathogenesis in mice.

Misfolding of the cellular prion protein (PrPC) into the scrapie prion protein (PrPSc) results in progressive, fatal, transmissible neurodegenerative conditions termed prion diseases. Experimental and epidemiological evidence point toward a protracted, clinically silent phase in prion diseases, yet there is no diagnostic test capable of identifying asymptomatic individuals incubating prions. In an effort to identify early biomarkers of prion diseases, we have compared global transcriptional profiles in brains from pre-symptomatic prion-infected mice and controls. We identified Cst7, which encodes cystatin F, as the most strongly upregulated transcript in this model. Early and robust upregulation of Cst7 mRNA levels and of its cognate protein was validated in additional mouse models of prion disease. Surprisingly, we found no significant increase in cystatin F levels in both cerebrospinal fluid or brain parenchyma of patients with Creutzfeldt-Jakob disease compared to Alzheimer's disease or non-demented controls. Our results validate cystatin F as a useful biomarker of early pathogenesis in experimental models of prion disease, and point to unexpected species-specific differences in the transcriptional responses to prion infections.