Abstract Number: PB0090
Meeting: ISTH 2021 Congress
Theme: Coagulation and Natural Anticoagulants » Critical Care and Perioperative
Background: Systemic Immunoglobulin Light Chain Amyloidosis (AL-Amyloidosis) is known to cause an acquired Factor X (FX) deficiency, but FX activity does not predict the hemorrhagic risk of these patients.
Aims: To determine if the Thrombin Generation Assay (TGA) could be a useful haemostatic parameter in the management of a patient affected with acquired FX deficiency, going through an invasive procedure.
Methods:
| Coagulation tests | Patient values | Normal values |
| PT (patient-to-normal) ratio | 1.82 | 0.84–1.20 |
| aPTT ratio | 1.47 | 0.86–1.20 |
| Protein C (%) | 260 | 72–160 |
| Protein S (%) | 126 | 58-114 |
| FII (%) | 115 | 73–113 |
| FVII (%) | 135 | 62–138 |
| FX (%) | 6 | 66–126 |
Basal blood tests examination
A 74-year-old female with a recent diagnosis of nephrotic syndrome had prolonged PT and aPTT (patient-to-normal) ratios corrected by mixing tests. A first coagulation assessment revealed a FX activity of 6% (baseline blood tests are reported in Table 1). The patients had to go through a kidney biopsy to confirm the clinical suspicion of AL-Amyloidosis. She was treated with 30 U/Kg of Prothrombin Complex Concentrate (PCC), which increased FX activity to 14% in 30 minutes. Coagulation testing was performed at baseline and 30 minutes after 30 U/Kg of PCC treatment. TGA was assessed in platelet-poor-plasma with 1pM Tissue Factor (TF) and 1µM synthetic phospholipids, and then in platelet-rich-plasma after addition of TF (1pM).
Results:
| PLASMA/triggers | LAG-TIME (min) | ETP (nM*min) | PEAK HEIGHT (nM) | |
| Patient (pre PCC) | PPP/1pM TF+1uM PL | 20 (>99°pct) | 2685 (97.5°pct) | 441 (97.5°pct) |
| Patient (pre PCC) | PRP/1pM TF | 21 (>99°pct) | 2570 (95°pct) | 141 (40°pct) |
| Patient (post PCC) | PPP/1pM TF+1uM PL | 18 (>99°pct) | Not measurable | 675 (<99°pct) |
| Patient (post PCC) | PRP/1pM TF | 18 (>99°pct) | Not measurable | 360 (<99°pct) |
| Healthy donor | PPP/1pM TF+1uM PL | 5 (20°pct) | 1987 (45°pct) | 310 (50°pct) |
| Healthy donor | PRP/1pM TF | 7 (30°pct) | 2039 (60°pct) | 137 (25°pct) |
| Patient prePCC + healthy donor | PPP/1pM TF+1uM PL | 9 (>99°pct) | 2437 (90°pct) | 443 (97.5°pct) |
| Patient postPCC + healthy donor | PPP/1pM TF+1uM PL | 9 (>99°pct) | 3522 (>99°pct) | 526 (>99°pct) |
Thrombin Generation Assay (TGA) parameters. TGA was assessed according to Hemker with a homemade method, performing the test in a platelet-poor-plasma (PPP) with 1pM of Tissue Factor (TF) and 1µM of synthetic phospholipids (PL), and then in platelets-rich-plasma (PRP) by addition of TF (1pM). “PCC” = Prothrombin Complex Concentrate.
As shown in Table 2, patient baseline TGA showed a very prolonged lag-time (>20 minutes) with the other parameters within the 97.5° percentiles. After PCC treatment, the prolonged lag-time was only partially corrected but ETP increased over measurable limits. We repeated the analysis after mixing with 50% of normal plasma as a source of FX, with a partial correction of the lag-time. The patient underwent renal biopsy without bleeding complications and the diagnosis of AL-amyloidosis was confirmed.
Conclusions: AL-Amyloidosis is known to provoke an acquired FX deficiency, but the consequences on the haemostasis are still not predictable. TGA could provide a better assessment of haemostasis in these patients in order to avoid unnecessary bleeding or thrombotic risks.
To cite this abstract in AMA style:
Arcudi S, Artoni A, Scalambrino E, Clerici M, Valsecchi F, Capecchi M, Tripodi A, Peyvandi F. Global Coagulation Assay in a Patient Affected by AL Amyloidosis [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/global-coagulation-assay-in-a-patient-affected-by-al-amyloidosis/. Accessed September 29, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/global-coagulation-assay-in-a-patient-affected-by-al-amyloidosis/