Abstract Number: PB0090
Meeting: ISTH 2021 Congress
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.
|Coagulation tests||Patient values||Normal values|
|PT (patient-to-normal) ratio||1.82||0.84–1.20|
|Protein C (%)||260||72–160|
|Protein S (%)||126||58-114|
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).
|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)|
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.
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