Purpose
Transbronchial biopsy (TBBx) histology and lavage (BAL) for microbiology are standard of care in lung transplant (LT) evaluation, but are inherently flawed. Plasma donor-derived cell-free DNA (dd-cfDNA) and viral DNA/RNA (vDNA/RNA) are promising biomarkers for more accurate assessment of allograft injury. Here we compare TBBx histology, BAL microbiology, dd-cfDNA and vDNA/RNA in matched samples.
Methods
40 post-LT samples (median 212 days) from 33 patients (median age: 61.0 yrs) were analyzed for dd-cfDNA fraction (Prospera™, Natera) and vDNA/RNA by metagenomic next-generation sequencing (mNGS) (Galileo™-ONE ArcBio) and correlated with clinical-pathologic (TBBx) diagnosis and BAL microbiology including Respiratory Viral Panel (RVP) multiplex PCR testing (BioFire RP2.1™; Biomerieux)
Results
Native lung diseases included: IPF (N=18), COPD (N=17), CF (N=2) and PAH (N=3). mNGS identified vDNA/RNA considered pathologic to LT in 27.5% (11/40) cases, including 2 previously undiagnosed cases of HIV-1, with a median dd-cfDNA of 1.14% [TABLE]. For 9 cases with “negative” BAL/RVP, putative respiratory viral infection was indicated by mNGS. vDNA/RNA was also detected in 3 cases of histologic acute cellular rejection (ACR), one of which had elevated dd-cfDNA. In 2/4 patients with chronic lung allograft dysfunction (CLAD), the dd-cfDNA fraction was elevated and associated with vDNA/RNA. Two stable patients (A0B0/X) with vDNA/RNA had elevated dd-cfDNA.
Conclusion
Detection of clinically significant vDNA/RNA signatures by plasma mNGS testing contradicted clinical-pathologic diagnoses in >25% of patients. Future studies will help better understand and adjudicate discrepant results between TBBx histology, BAL microbiology, dd-cfDNA and mNGS. mNGS testing offers promise for properly assigning clinical-pathologic diagnosis in the assessment of LT health and may support the appropriate adjudication of elevated dd-cfDNA fractions.
Tabled
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| Characteristics from LT Patients with Clinically Significant vDNA/RNA Signatures from mNGS Testing | ||||||
|---|---|---|---|---|---|---|
| Patient | Time post-LT (d) | Histology (ISHLT) | Clinical Diagnosis | RVP PCR | DNA and RNA Virus by mNGS | dd-cfDNA (%) |
| 57M | 199 | A1B1 | CLAD+ACR | Negative | CMV | 0.56 |
| 37M | 1466 | A0B0 | CLAD | Negative | HIV-1 | 1.66 |
| 46M | 401 | A0B0 | CLAD | Negative | Rubella | 1.53 |
| 69M | 117 | A2BX | ACR | Negative | RSV-B | 0.37 |
| 67M | 1237 | A0BX | CLAD | Negative | SARS-CoV-2 | 0.44 |
| 62F | 76 | A0BX | INFXN | Negative, Staph aureus | Influenza A | 1.24 |
| 62F | 363 | A2B0 | ACR | Negative | Enterovirus-B | 1.09 |
| 61F | 359 | A0B0 | STABLE | Negative | HIV-1 | 0.06 |
| 70F | 199 | A0B0 | STABLE | Negative | Influenza B | 1.19 |
| 29F | 188 | A0BX | STABLE | Negative | Influenza B | 1.96 |
| 66M | 89 | A0BX | INFXN | Negative | SARS-CoV-2 | 0.68 |
Article info
Identification
Copyright
© 2022 Published by Elsevier Inc.
