Table 1.
Patient’s Timeline.
| Day | Event | Hours post-HDMTX | Serum creatinine (µmol/L) | Methotrexate concentration |
|---|---|---|---|---|
| Day -41 | Diagnosed with DLBCL with cerebral vessel involvement | |||
| Day -33 | R-CHOP, cycle #1 | |||
| Day -12 | R-CHOP, cycle #2 | |||
| Day 0 | HDMTX, cycle #1 | 0 (=1400h) | 63 (at baseline) | |
| AKI identified High-dose leucovorin started at 1000 mg/m2 IV every 3 hours (10× standard dose) |
18 | 226 | 175 µmol/L (>35× the toxic threshold) | |
| Day 1 | Progressive AKI | 41 | 374 | 31 µmol/L (persistently toxic concentration) |
| Neurotoxicity (status epilepticus), patient transferred to ICU | 42 | |||
| Glucarpidase procured and administered, 50 units/kg IV over 5 minutes | 52 | 434 | ||
| Day 2 | Discrepancy between methotrexate concentration by immunoassay and LC-MS/MS | 60 | 479 | Immunoassay: 7.26 µmol/L LC-MS/MS: <0.05 µmol/L |
| Day 6 | Peak serum creatinine reached; patient remained nonoliguric with no acute indications for dialysis | 608 | Immunoassay: 1.60 µmol/L | |
| Day 31 | Patient transferred to ward | 88 | ||
| Day 38 | R-CHOP, cycle #3 | 63 | ||
| Day 44 | Patient discharged to rehab | 60 |
Note. To convert serum creatinine from µmol/L to mg/dL, multiply by 0.0113. HDMTX = high-dose methotrexate; DLBCL = diffuse large B-cell lymphoma; R-CHOP = rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone; AKI = acute kidney injury; IV = intravenous; ICU = intensive care unit; LC-MS/MS = liquid chromatography-tandem mass spectrometry.