Table 1. Pertinent initial laboratory test results.

Lab test	Patient’s result (normal range)
Hemoglobin	6.5 (11.8 – 15.8) g/dL
MCV	96 (80 – 100) fL
Platelets	89 (140 – 440) Thou/uL
AST	35 (0 – 37) U/L
ALT	19 (0 – 40) U/L
ALK PHOS	70 (39 – 117) U/L
LDH	975 (94 – 250) U/L
Haptoglobin	< 20 (25 – 200) mg/dL
Blood smear	2 + schistocytes (none expected)
ADAMTS13	75% (50 – 160%)

MCV = mean corpuscular volume; AST = liver enzymes aspartate aminotransferase; ALT = alanine aminotransferase; ALK PHOS = alkaline phosphatase; LDH = lactate dehydrogenase. A disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity level was measured with a direct activity assay using Fluorescence Resonance Energy Transfer [FRETS] with the VWF (Von Willebrand Factor) 73 fragment as the substrate. Severe deficiency as in TTP is 5 – 10% activity level.