I have an interesting 53 year old woman who is ~160 days from her allotransplant for AML, who presented with worsening cytopenias, Hgb 6.5 (baseline 9), platelets 6 (baseline 60s), normal WBC. She was noted to have hemolytic labs positive (haptoglobin 5, LDH 555, bilirubin 1.2 mostly indirect), and smear shows significant schistocytes. Bone marrow shows no evidence of AML. Tacrolimus was discontinued six days ago but no difference in hemolysis. Patient is requiring RBC transfusion every fifth day and platelet transfusion once a week. No evidence of AKI, cardiac or pulmonary or cns compromise. Would you think this is TA-TMA? And would you offer eculizumab in this situation? Would love to know how you would approach this case.
Yes have to determine if having delayed effect of tacro TMA or TA-TMA. One test that you can use to determine is the terminal complement complex. This can be sent out to Quest diagnostics. "SC5b-9 Level Terminal Complement Complex" https://testdirectory.questdiagnostics.com/test/test-detail/17843/sc5b-9-level-terminal-complement-complex?cc=MASTER
If you diagnose TA-TMA, then eculizumab could be useful, but very high risk for infectious complications post allo transplant. An emerging therapy that may be better is Narsoplimab: https://ascopubs.org/doi/10.1200/JCO.21.02389?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
I would attempt to get this drug from the company Omeros if you diagnose TA-TMA.
