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Table 1 Baseline characteristics of the study population

From: Cardiovascular risk factors are major determinants of thrombotic risk in patients with the lupus anticoagulant

Variable

Number (% missing)

Overall (n = 150)

Prior history of thrombosis (n = 98)

Without prior history of thrombosis (n = 52)

p a

No event during follow-up (n = 118)

Event during follow-up (n = 32)

p a

Demographic characteristics

 Age at entry (years)

150 (0.0%)

41.3 [32.3-60.2]

39.2 [29.9-54.7]

48.4 [35.6-62.9]

0.014

40.1 [31.8-58.2]

46.0 [32.5-63.8]

0.210

 Female gender

150 (0.0%)

122 (81.3%)

82 (83.7%)

40 (76.9%)

0.313

98 (83.1%)

24 (75.0%)

0.300

 BMI (kg/m2)

147 (2.0%)

25.4 [22.5-29.4]

25.6 [22.4-29.9]

25.1 [22.8-28.9]

0.659

25.0 [22.2-29.3]

27.5 [24.6-30.1]

0.054

Clinical history

 Prior history of thrombosis

150 (0.0%)

98 (65.3%)

-

-

-

77 (65.3%)

21 (65.6%)

0.969

-Arterial

150 (0.0%)

21 (14.0%)

-

-

-

15 (12.7%)

6 (18.8%)

0.383

-Venous

150 (0.0%)

84 (56.0%)

-

-

-

68 (57.6%)

16 (50.0%)

0.441

-Both

150 (0.0%)

7 (4.7%)

-

-

-

6 (5.1%)

1 (3.1%)

0.538

 Prior history of pregnancy complicationsb

94 (0.0%)

40 (42.6%)

-

-

-

32 (42.7%)

8 (42.1%)

0.965

 Established APS

150 (0.0%)

111 (74.0%)

98 (100.0%)

13 (25.0%)

<0.0001

89 (75.4%)

22 (68.8%)

0.445

 Family history of thrombosis

150 (0.0%)

48 (32.0%)

33 (33.7%)

15 (28.9%)

0.546

40 (33.9%)

8 (25.0%)

0.339

Comorbidities

 Hypertension

150 (0.0%)

44 (29.3%)

26 (26.5%)

18 (34.6%)

0.301

34 (28.8%)

10 (31.3%)

0.788

 Diabetes

150 (0.0%)

10 (6.7%)

5 (5.1%)

5 (9.6%)

0.292

4 (3.4%)

6 (18.8%)

0.002

 Statin exposure

150 (0.0%)

10 (6.7%)

8 (8.2%)

2 (3.9%)

0.313

7 (5.9%)

3 (9.4%)

0.445

 Autoimmune rheumatic diseasesc

150 (0.0%)

48 (32.0%)

31 (31.7%)

17 (32.7%)

0.895

39 (33.1%)

9 (28.1%)

0.596

-SLE

150 (0.0%)

29 (19.3%)

20 (20.4%)

9 (17.3%)

0.647

24 (20.3%)

5 (15.6%)

0.549

-LLD

150 (0.0%)

19 (12.7%)

11 (11.2%)

8 (15.4%)

0.466

15 (12.7%)

4 (12.5%)

0.975

 Thrombophiliad

150 (0.0%)

47 (31.3%)

30 (30.6%)

17 (32.7%)

0.794

35 (29.7%)

12 (37.5%)

0.396

 Active smoker at baseline

150 (0.0%)

45 (30.0%)

25 (25.5%)

20 (38.5%)

0.099

30 (25.4%)

15 (46.9%)

0.019

Anticoagulation at baseline

 VKA

150 (0.0%)

70 (46.7%)

68 (69.4%)

2 (3.9%)

<0.0001

55 (46.6%)

15 (46.9%)

0.979

 Low molecular weight heparin (LMWH)

150 (0.0%)

14 (9.3%)

11 (11.2%)

3 (5.8%)

0.381

14 (11.9%)

0 (0.0%)

0.041

 Low dose aspirin (LDA)

150 (0.0%)

37 (24.7%)

24 (24.5%)

13 (25.0%)

0.945

29 (24.6%)

8 (25.0%)

0.961

 None

150 (0.0%)

54 (36.0%)

17 (17.4%)

37 (71.2%)

<0.0001

43 (36.4%)

11 (34.4%)

0.829

Disease-defining autoantibodies

 aPTT-LA (s)

150 (0.0%)

87.4 [70.1-117.5]

90.2 [72.5-118.1]

82.8 [64.9-115.6]

0.165

85.9 [69.0-109.3]

115.0 [74.4-132.5]

0.040

 aPTT-LA ratioe

150 (0.0%)

2.6 [2.1-3.4]

2.6 [2.1-3.5]

2.4 [1.9-3.9]

0.165

2.5 [2.0-3.2]

3.4 [2.2-3.9]

0.041

 aβ2-GPI IgM (MPL)

148 (1.3%)

5.6 [2.8-15.7]

5.1 [2.5-14.6]

7.1 [3.0-26.7]

0.197

5.3 [2.6-15.5]

7.1 [3.2-17.1]

0.412

 aβ2-GPI IgG (GPL)

149 (0.7%)

9.8 [2.3-50.0]

18.9 [3.1-68.5]

5.5 [1.7-17.0]

0.005

9.4 [2.3-48.6]

16.3 [2.6-81.0]

0.522

 aCL IgM (MPL)

150 (0.0%)

9.1 [3.7-23.0]

7.6 [3.4-16.2]

13.1 [5.1-32.3]

0.001

8.7 [3.5-21.1]

10.6 [5.5-25.5]

0.286

 aCL IgG (GPL)

150 (0.0%)

19.1 [6.3-71.7]

35.1 [8.9-99.9]

10.8 [5.5-29.9]

0.037

18.4 [6.0-65.9]

26.6 [7.0-111.9]

0.236

 LA alone

150 (0.0%)

42 (28.4%)

23 (23.7%)

19 (37.3%)

0.082

34 (29.3%)

8 (25.0%)

0.632

 LA + aβ2-GPI (ISTH cut-off)f

148 (1.3%)

105 (71.0%)

73 (75.3%)

32 (62.8%)

0.111

81 (69.8%)

24 (75.0%)

0.568

 LA + aCL (ISTH cut-off)f

150 (0.0%)

67 (44.7%)

51 (52.0%)

16 (30.8%)

0.013

50 (42.4%)

17 (53.1%)

0.278

 Triple positivity (ISTH cut-off)f

148 (1.3%)

64 (43.2%)

49 (50.5%)

15 (29.4%)

0.014

47 (40.5%)

17 (53.1%)

0.202

 Triple positivity (Padova cut-off)f

148 (1.3%)

87 (58.8%)

59 (60.8%)

28 (54.9%)

0.487

66 (56.9%)

21 (65.6%)

0.375

 Triple positivity (local cut-off)f

148 (1.3%)

93 (62.8%)

64 (66.0%)

29 (56.9%)

0.275

72 (62.1%)

21 (65.6%)

0.712

LA-related autoantibodies

 Domain I abs (CU)

144 (6.0%)

30.3 [2.5-256.0]

64.3 [4.1-498.2]

5.9 [1.5-59.9]

0.002

30.8 [3.2-245.3]

24.8 [1.5-265.4]

0.580

 Anti-protein Z IgM

144 (4.0%)

6.0 [4.1-9.1]

5.5 [3.8-8.8]

6.3 [4.6-9.6]

0.210

5.9 [4.1-9.3]

6.0 [4.4-8.9]

0.651

 Anti-protein Z IgG

144 (4.0%)

3.4 [2.6-5.7]

3.4 [2.6-6.0]

3.3 [2.5-5.6]

0.584

3.4 [2.6-5.6]

3.4 [2.4-6.0]

0.888

 Antiprothrombin IgM

146 (2.7%)

5.4 [3.2-10.1]

5.2 [2.6-8.5]

6.5 [3.7-13.3]

0.031

5.4 [3.2-9.5]

7.5 [3.6-11.0]

0.331

 Antiprothrombin IgG

146 (2.7%)

4.5 [2.1-8.7]

5.2 [1.7-11.2]

4.1 [2.9-6.3]

0.407

4.3 [2.0-8.7]

5.8 [2.3-9.6]

0.514

 Annexin A5 ratio (%)

143 (4.7%)

205 [175-250]

193 [164-240]

239 [186-258]

0.001

218 [176-254]

186 [164-239]

0.164

Selected laboratory parameters

 C-reactive protein (mg/dL)

148 (1.3%)

0.1 [0.0-0.8]

0.2 [0.0-1.0]

0.1 [0.0-0.4]

0.087

0.1 [0.0-0.7]

0.4 [0.0-0.8]

0.721

 Triglycerides (mg/dL)

148 (1.3%)

107 [82-153]

110 [87-155]

103 [70-150]

0.354

106 [82-145]

131 [82-191]

0.197

 Cholesterol (mg/dL)

149 (0.7%)

196 [174-225]

191 [168-221]

203 [178-232]

0.239

193 [172-221]

202 [180-233]

0.257

 HDL/LDL ratio

144 (4.0%)

0.45 [0.35-0.61]

0.44 [0.35-0.60]

0.49 [0.35-0.67]

0.498

0.46 [0.35-0.63]

0.43 [0.35-0.57]

0.533

 Homocysteine (μmol/L)

142 (5.3%)

9.8 [8.4-13.7]

9.7 [8.4-13.8]

10.8 [8.6-13.0]

0.484

9.8 [8.5-12.8]

10.1 [8.2-15.5]

0.519

 Fibrinogen (mg/dL)

150 (0.0%)

377 [318-430]

390 [320-456]

357 [297-399]

0.011

370 [313-430]

396 [355-442]

0.169

  1. Distribution overall as well as by prior history of thrombosis and prospective thrombotic event status
  2. a p values were derived using Wilcoxon’s rank-sum tests (p values ≤ 0.05 are reported in bold font)
  3. bPregnancy complications were defined according to Sapporo criteria in the subgroup of 94 females who had at least one documented pregnancy
  4. cAutoimmune rheumatic diseases were defined as a composite of systemic lupus erythematosus (SLE) and lupus-like disease (LLD) according to a local panel of rheumatology experts
  5. dHereditary thrombophilia was defined as the presence of at least one of the following factors: (1) heterozygous or homozygous factor V Leiden, (2) deficiency of antithrombin III, (3) deficiency of protein C or protein S, (4) hyperhomocysteinemia, (5) heterozygous or homozygous prothrombin G20210A polymorphism, and (6) high coagulation factor VIII
  6. eThe aPTT ratio is defined by the ratio of the lupus-sensitive aPTT of a patient divided by the mean of the lupus-sensitive aPTT in healthy controls at our department (mean = 34.09 s, SD = 0.476)
  7. fCut-offs were defined as follows: ISTH cut-off: aCL > 40GPL/MPL U/mL, aβ2-GPI IgG > 8 GPL/MPL U/mL; Padova cut-off (i.e., the cut-off corresponding to the 99th percentile at the laboratory of Prof. Vittorio Pengo (University of Padova, Italy (personal communication)): aCL > 17 GPL/MPL U/mL, aβ2-GPI IgG > 8 GPL/MPL U/mL; local cut-off (i.e., the 99th percentile at the coagulation laboratory of the Medical University of Vienna): aCL ≥ 10 GPL U/mL for aCL IgG, ≥7 for aCL IgM (Orgentec assays), or >15 GPL/MPL U/mL (Varelisa assays)
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BMC Medicine

ISSN: 1741-7015

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