Otomo et al reported the Antiphospholipid Score for evaluating patients for the Antiphospholipid Syndrome. It can help to identify a patient at increased risk for thrombosis. The authors are from are from Hokkaido University in Sapporo.
Patient selection: presence of an autoimmune disease
Parameters:
(1) aPTT mixing with confirmatory test ratio
(2) KCT (Kaoling clotting time) mixing test
(3) dRVVT (dilute Russell viper venoma test) mixing with confirmatory test ratio
(4) titer of IgG aCL in GPL (anticardiolipin antibody in IgG phospholipid units)
(5) IgM aCL in MPL (anticardiolipin antibody in IgM phospholipud units
(6) titer of IgG anti-beta2GPI (beta-2 glycoprotein I)
(7) IgM anti2beta2 GPI
(8) titer of IgG anti-PS/PT (phosphatidylserine/prothrombin complex)
(9) IgM anti-PS-PT
|
Parameter |
Finding |
Points |
|
aPTT mixing test and confirmation test ratio |
aPTT mixing > 49 seconds, confirmation test ratio > 1.3 |
7 |
|
|
> 49 seconds, confirmation test 1.11 to 1.3 |
6 |
|
|
> 49 seconds, confirmation test <= 1.1 |
5 |
|
|
<= 49 seconds |
0 |
|
KCT mixing test |
> 29 seconds |
8 |
|
|
<= 29 seconds |
0 |
|
dRVVT mixing test and confirmation test ratio |
dRVVT mixing > 45 seconds, confirmation test ratio > 1.3 |
6 |
|
|
> 45 seconds, confirmation test 1.11 to 1.3 |
5 |
|
|
> 45 seconds, confirmation test <= 1.1 |
4 |
|
|
<= 45 seconds |
0 |
|
IgG aCL |
high titer (> 30 GPL units) |
20 |
|
|
low or moderate titer (18.6 to 30) |
4 |
|
|
negative (<= 18.5) |
0 |
|
IgM aCL |
> 7 MPL units |
2 |
|
|
<= 7 |
0 |
|
IgG anti-beta2 GPI |
high titer (>15 units) |
20 |
|
|
low or moderate titer (2.3 to 15) |
6 |
|
|
negative (<= 2.2) |
0 |
|
IgM anti-beta2 GPI |
> 6 units |
1 |
|
|
<= 6 units |
0 |
|
IgG anti-PS/PT |
high titer (>10 units) |
20 |
|
|
low or moderate titers (2.1 to 10 units) |
13 |
|
|
negative (<= 2) |
0 |
|
IgM anti-PS/PT |
> 9.2 units |
8 |
|
|
<= 9.2 units |
0 |
where:
• A mixing test is presumed to be testing after mixing with normal plasma.
total score =
= SUM(points for all 9 parameters)
Interpretation:
• minimum score: 0
• maximum score: 92 (maximum seen in study patients 86)
• The higher the score the greater the risk of clinical antiphospholipid syndrome.
• A score >= 30 had an odds ratio of 5.3 for thrombosis.
|
Total Score |
APS Manifestations |
|
0 |
10% |
|
1 to 9 |
26% |
|
10 to 29 |
29% |
|
30 to 59 |
56% |
|
>= 60 |
89% |
Performance:
• Coagulation tests show considerable variability and reproducibility requires careful control of the tests.
• The area under the ROC curve for APS manifestations was 0.75.
Specialty: Hematology Oncology, Clinical Laboratory, Immunology/Rheumatology
