ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005


The Latest on X

Kidney Week

Please note that you are viewing an archived section from 2023 and some content may be unavailable. To unlock all content for 2023, please visit the archives.

Abstract: FR-OR68

The Molecular Microscope Diagnostics System (MMDx) Does Not Identify Molecular T Cell-Mediated Rejection (TCMR) in Cases with Borderline Changes or Isolated Intimal Arteritis in the Absence of Microvascular Inflammation

Session Information

Category: Transplantation

  • 2102 Transplantation: Clinical


  • Schachtner, Thomas, UniversitatsSpital Zurich, Zurich, Zürich, Switzerland
  • Weidmann, Lukas, UniversitatsSpital Zurich, Zurich, Zürich, Switzerland
  • Harmacek, Dusan, UniversitatsSpital Zurich, Zurich, Zürich, Switzerland
  • Bortel, Nicola, UniversitatsSpital Zurich, Zurich, Zürich, Switzerland
  • López, Kai Castrezana, UniversitatsSpital Zurich, Zurich, Zürich, Switzerland
  • Korach, Raphael, UniversitatsSpital Zurich, Zurich, Zürich, Switzerland
  • Mueller, Thomas F., UniversitatsSpital Zurich, Zurich, Zürich, Switzerland

Borderline changes suspicious for T-cell mediated rejection (TCMR) and isolated intimal arteritis (v-lesion) represent a particular challenge. Even though the Molecular Microscope Diagnostics System (MMDx) has not been trained on borderline changes and v-lesions, it has been suggested that MMDx may reclassify a subgroup of cases to molecular TCMR.


In this single-center cohort of 326 kidney allograft biopsies assessed by histology and MMDx at the University Hospital Zurich, we analyzed 153 cases with isolated tubulitis (i0, t1-3; n=114), borderline changes (n=10), and isolated intimal arteritis (i0, t0-2, v1; n=39) in the presence (n=81) and absence (n=72) of microvascular inflammation (MVI). 83 cases without histologic lesions suspicious for TCMR (i0, t0, v0) were used for comparison of rejection phenotype scores. Any cases with overlapping pathologies were excluded from the analysis.


41 of 81 cases (51%) with suspicion for TCMR and MVI showed molecular rejection (30 cases with molecular ABMR, 4 cases with molecular ABMR/TCMR (2 cases with isolated tubulitis, 1 case with borderline changes, 1 case with isolated intimal arteritis), and 7 cases with minor ABMR) compared to 6 of 32 cases (19%) without suspicion for TCMR but MVI (5 cases with molecular ABMR, 1 case with molecular ABMR/TCMR; p=0.003). However, 1 of 72 cases (1%) only with suspicion for TCMR, but no MVI showed molecular rejection (1 case with minor ABMR). No pure molecular TCMR was identified in any group. 11 of 153 cases (7%) with suspicion for TCMR showed a TCMR phenotype score (R2) ≥0.10 (7 cases with isolated tubulitis and 4 cases with isolated intimal arteritis) compared to 5 of 83 cases (6%) without suspicion for TCMR (p=1).


MMDx may identify molecular TCMR among cases with MVI irrespective of histologic suspicion for TCMR. MMDx does not identify molecular TCMR in cases with isolated tubulitis, borderline changes, or intimal arteritis without MVI. TCMR phenotype scores do not differentiate between isolated tubulitis, borderline changes, isolated intimal arteritis, or no histologic lesions suspicious for TCMR.


  • Private Foundation Support