Methods for treating and diagnosing systemic lupus erythematosus
Methods and reagents for diagnosing, prognosing, and treating systemic lupus erythematosus (SLE) are disclosed, involving calculating an SLE risk score for a subject based on a level of each of an erythrocyte C4d (EC4d) marker, a B-cell C4d (BC4d) marker, antinuclear antibodies (ANA), anti-Smith antibodies (anti-Sm) and optional rule-out markers (SS-B/La, Scl-70, Jo-1, CENP, MCV).
1. A method of treating systemic lupus erythematosus (SLE) in a subject identified as having SLE based on a systemic lupus erythematosus risk score, the method comprising:
(A) determining a level of erythrocyte C4d marker, a level of B-cell C4d marker, a level of anti-nuclear antibody, a level of anti-Sjögren's syndrome type B antigen antibody, a level of anti-Scl-70 antibody, a level of anti-Jo-1 antibody, and a level of anti-centromere protein B antibody in a blood sample from the subject;
(B) calculating a systemic lupus erythematosus index score with the level of the erythrocyte C4d marker, the level of the B-cell C4d marker, the level of the anti-nuclear antibody, the level of anti-Sjögren's syndrome type B antigen antibody, the level of anti-Scl-70 antibody, the level of anti-Jo-1 antibody, and the level of anti-centromere protein B antibody with the equation:
Index=−5.2626+0.9877 ×ANAComp+ [0.2955×log( EC 4 d )+1.0260×log( BC 4 d )]−2.4944 ×SpecComp;
wherein:
(i) Index is the systemic lupus erythematosus index score;
(ii) ANAComp is:
(a) 0, when the level of anti-nuclear antibody <20 units, as measured by an enzyme-linked immunosorbent assay;
(b) 1, when the level of anti-nuclear antibody is ≥20 units and <60 units, as measured by an enzyme-linked immunosorbent assay; or
(c) 2, when the level of anti-nuclear antibody ≥60 units, as measured by an enzyme-linked immunosorbent assay;
(iii) log is natural log;
(iv) EC4d is net mean fluorescence intensity of erythrocyte C4d marker, as measured by fluorescence activated flow cytometry;
(v) BC4d is net mean fluorescence intensity of B-cell C4d marker, as measured by fluorescence activated flow cytometry; and
(vi) SpecComp is:
(a) 0, when the level of anti-Sjögren's syndrome type B antigen antibody is ≤10 Units/mL; the level of anti-Scl-70 antibody is ≤10 Units/mL; the level of anti-Jo-1 antibody is ≤10 Units/mL; and the level of anti-centromere protein B antibody is ≤10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(b) 1, when one or more of the level of anti-Sjögren's syndrome type B antigen antibody is >10 Units/mL; the level of anti-Scl-70 antibody >10 Units/mL; the level of anti-Jo-1 antibody is >10 Units/mL; or the level of anti-centromere protein B antibody is >10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(C) identifying the subject as having SLE when the index score is >0; and
(D) treating the subject identified as having SLE in step (C) with an effective amount of belimumab.
2. A method of treating systemic lupus erythematosus (SLE) in a subject identified as having SLE based on a systemic lupus erythematosus risk score, the method comprising:
(A) determining a level of erythrocyte C4d marker, a level of B-cell C4d marker, a level of anti-nuclear antibody, a level of anti-Sjögren's syndrome type B antigen antibody, a level of anti-Scl-70 antibody, a level of anti-Jo-1 antibody, and a level of anti-centromere protein B antibody in a blood sample from the subject;
(B) calculating a systemic lupus erythematosus index score with the level of the erythrocyte C4d marker, the level of the B-cell C4d marker, the level of the anti-nuclear antibody, the level of anti-Sjögren's syndrome type B antigen antibody, the level of anti-Scl-70 antibody, the level of anti-Jo-1 antibody, and the level of anti-centromere protein B antibody with the equation:
Index=−5.2626+0.9877 ×ANAComp [0.2955×log( EC 4 d )+1.0260×log( BC 4 d )]−2.4944 ×SpecComp;
wherein:
(i) Index is the systemic lupus erythematosus index score;
(ii) ANAComp is:
(a) 0, when the level of anti-nuclear antibody <20 units, as measured by an enzyme-linked immunosorbent assay;
(b) 1, when the level of anti-nuclear antibody is ≥20 units and <60 units, as measured by an enzyme-linked immunosorbent assay; or
(c) 2, when the level of anti-nuclear antibody ≥60 units, as measured by an enzyme-linked immunosorbent assay;
(iii) log is natural log;
(iv) EC4d is net mean fluorescence intensity of erythrocyte C4d marker, as measured by fluorescence activated flow cytometry;
(v) BC4d is net mean fluorescence intensity of B-cell C4d marker, as measured by fluorescence activated flow cytometry; and
(vi) SpecComp is:
(a) 0, when the level of anti-Sjögren's syndrome type B antigen antibody is ≤10 Units/mL; the level of anti-Scl-70 antibody is ≤10 Units/mL; the level of anti-Jo-1 antibody is ≤10 Units/mL; and the level of anti-centromere protein B antibody is ≤10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(b) 1, when one or more of the level of anti-Sjögren's syndrome type B antigen antibody is >10 Units/mL; the level of anti-Scl-70 antibody >10 Units/mL; the level of anti-Jo-1 antibody is >10 Units/mL; or the level of anti-centromere protein B antibody is >Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(C) identifying the subject as having SLE when the index score is >0; and
(D) treating the subject identified as having SLE in step (C) with an effective amount of cyclophosphami de.
3. A method of treating systemic lupus erythematosus (SLE) in a subject identified as having SLE based on a systemic lupus erythematosus risk score, the method comprising:
(A) determining a level of erythrocyte C4d marker, a level of B-cell C4d marker, a level of anti-nuclear antibody, a level of anti-Sjögren's syndrome type B antigen antibody, a level of anti-Scl-70 antibody, a level of anti-Jo-1 antibody, and a level of anti-centromere protein B antibody in a blood sample from the subject;
(B) calculating a systemic lupus erythematosus index score with the level of the erythrocyte C4d marker, the level of the B-cell C4d marker, the level of the anti-nuclear antibody, the level of anti-Sjögren's syndrome type B antigen antibody, the level of anti-Scl-70 antibody, the level of anti-Jo-1 antibody, and the level of anti-centromere protein B antibody with the equation:
Index=−5.2626+0.9877 ×ANAComp [0.2955×log( EC 4 d )+1.0260×log( BC 4 d )]−2.4944 ×SpecComp;
wherein:
(i) Index is the systemic lupus erythematosus index score;
(ii) ANAComp is:
(a) 0, when the level of anti-nuclear antibody <20 units, as measured by an enzyme-linked immunosorbent assay;
(b) 1, when the level of anti-nuclear antibody is ≥20 units and <60 units, as measured by an enzyme-linked immunosorbent assay; or
(c) 2, when the level of anti-nuclear antibody ≥60 units, as measured by an enzyme-linked immunosorbent assay;
(iii) log is natural log;
(iv) EC4d is net mean fluorescence intensity of erythrocyte C4d marker, as measured by fluorescence activated flow cytometry;
(v) BC4d is net mean fluorescence intensity of B-cell C4d marker, as measured by fluorescence activated flow cytometry; and
(vi) SpecComp is:
(a) 0, when the level of anti-Sjögren's syndrome type B antigen antibody is ≤10 Units/mL; the level of anti-Scl-70 antibody is ≤10 Units/mL; the level of anti-Jo-1 antibody is ≤10 Units/mL; and the level of anti-centromere protein B antibody is ≤10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(b) 1, when one or more of the level of anti-Sjögren's syndrome type B antigen antibody is >10 Units/mL; the level of anti-Scl-70 antibody >10 Units/mL; the level of anti-Jo-1 antibody is >10 Units/mL; or the level of anti-centromere protein B antibody is >10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(C) identifying the subject as having SLE when the index score is >0; and
(D) treating the subject identified as having SLE in step (C) with an effective amount of methotrexate.
4. A method of treating systemic lupus erythematosus (SLE) in a subject identified as having SLE based on a systemic lupus erythematosus risk score, the method comprising:
(A) determining a level of erythrocyte C4d marker, a level of B-cell C4d marker, a level of anti-nuclear antibody, a level of anti-Sjögren's syndrome type B antigen antibody, a level of anti-Scl-70 antibody, a level of anti-Jo-1 antibody, and a level of anti-centromere protein B antibody in a blood sample from the subject;
(B) calculating a systemic lupus erythematosus index score with the level of the erythrocyte C4d marker, the level of the B-cell C4d marker, the level of the anti-nuclear antibody, the level of anti-Sjögren's syndrome type B antigen antibody, the level of anti-Scl-70 antibody, the level of anti-Jo-1 antibody, and the level of anti-centromere protein B antibody with the equation:
Index=−5.2626+0.9877 ×ANAComp [0.2955×log( EC 4 d )+1.0260×log( BC 4 d )]−2.4944 ×SpecComp;
wherein:
(i) Index is the systemic lupus erythematosus index score;
(ii) ANAComp is:
(a) 0, when the level of anti-nuclear antibody <20 units, as measured by an enzyme-linked immunosorbent assay;
(b) 1, when the level of anti-nuclear antibody is ≥20 units and <60 units, as measured by an enzyme-linked immunosorbent assay; or
(c) 2, when the level of anti-nuclear antibody ≥60 units, as measured by an enzyme-linked immunosorbent assay;
(iii) log is natural log;
(iv) EC4d is net mean fluorescence intensity of erythrocyte C4d marker, as measured by fluorescence activated flow cytometry;
(v) BC4d is net mean fluorescence intensity of B-cell C4d marker, as measured by fluorescence activated flow cytometry; and
(vi) SpecComp is:
(a) 0, when the level of anti-Sjögren's syndrome type B antigen antibody is ≤10 Units/mL; the level of anti-Scl-70 antibody is ≤10 Units/mL; the level of anti-Jo-1 antibody is ≤10 Units/mL; and the level of anti-centromere protein B antibody is ≤10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(b) 1, when one or more of the level of anti-Sjögren's syndrome type B antigen antibody is >10 Units/mL; the level of anti-Scl-70 antibody >10 Units/mL; the level of anti-Jo-1 antibody is >10 Units/mL; or the level of anti-centromere protein B antibody is >10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(C) identifying the subject as having SLE when the index score is >0; and
(D) treating the subject identified as having SLE in step (C) with an effective amount of azathioprine.
5. A method of treating systemic lupus erythematosus (SLE) in a subject identified as having SLE based on a systemic lupus erythematosus risk score, the method comprising:
(A) determining a level of erythrocyte C4d marker, a level of B-cell C4d marker, a level of anti-nuclear antibody, a level of anti-Sjögren's syndrome type B antigen antibody, a level of anti-Scl-70 antibody, a level of anti-Jo-1 antibody, and a level of anti-centromere protein B antibody in a blood sample from the subject;
(B) calculating a systemic lupus erythematosus index score with the level of the erythrocyte C4d marker, the level of the B-cell C4d marker, the level of the anti-nuclear antibody, the level of anti-Sjögren's syndrome type B antigen antibody, the level of anti-Scl-70 antibody, the level of anti-Jo-1 antibody, and the level of anti-centromere protein B antibody with the equation:
Index=−5.2626+0.9877 ×ANAComp [0.2955×log( EC 4 d )+1.0260×log( BC 4 d )]−2.4944 ×SpecComp;
wherein:
(i) Index is the systemic lupus erythematosus index score;
(ii) ANAComp is:
(a) 0, when the level of anti-nuclear antibody <20 units, as measured by an enzyme-linked immunosorbent assay;
(b) 1, when the level of anti-nuclear antibody is ≥20 units and <60 units, as measured by an enzyme-linked immunosorbent assay; or
(c) 2, when the level of anti-nuclear antibody ≥60 units, as measured by an enzyme-linked immunosorbent assay;
(iii) log is natural log;
(iv) EC4d is net mean fluorescence intensity of erythrocyte C4d marker, as measured by fluorescence activated flow cytometry;
(v) BC4d is net mean fluorescence intensity of B-cell C4d marker, as measured by fluorescence activated flow cytometry; and
(vi) SpecComp is:
(a) 0, when the level of anti-Sjögren's syndrome type B antigen antibody is ≤10 Units/mL; the level of anti-Scl-70 antibody is ≤10 Units/mL; the level of anti-Jo-1 antibody is ≤10 Units/mL; and the level of anti-centromere protein B antibody is ≤10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(b) 1, when one or more of the level of anti-Sjögren's syndrome type B antigen antibody is >10 Units/mL; the level of anti-Scl-70 antibody >10 Units/mL; the level of anti-Jo-1 antibody is >10 Units/mL; or the level of anti-centromere protein B antibody is >10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(C) identifying the subject as having SLE when the index score is >0; and
(D) treating the subject identified as having SLE in step (C) with an effective amount of leflunomide.
6. A method of treating systemic lupus erythematosus (SLE) in a subject identified as having SLE based on a systemic lupus erythematosus risk score, the method comprising:
(A) determining a level of erythrocyte C4d marker, a level of B-cell C4d marker, a level of anti-nuclear antibody, a level of anti-Sjögren's syndrome type B antigen antibody, a level of anti-Scl-70 antibody, a level of anti-Jo-1 antibody, and a level of anti-centromere protein B antibody in a blood sample from the subject;
(B) calculating a systemic lupus erythematosus index score with the level of the erythrocyte C4d marker, the level of the B-cell C4d marker, the level of the anti-nuclear antibody, the level of anti-Sjögren's syndrome type B antigen antibody, the level of anti-Scl-70 antibody, the level of anti-Jo-1 antibody, and the level of anti-centromere protein B antibody with the equation:
Index=−5.2626+0.9877 ×ANAComp [0.2955×log( EC 4 d )+1.0260×log( BC 4 d )]−2.4944 ×SpecComp;
wherein:
(i) Index is the systemic lupus erythematosus index score;
(ii) ANAComp is:
(a) 0, when the level of anti-nuclear antibody <20 units, as measured by an enzyme-linked immunosorbent assay;
(b) 1, when the level of anti-nuclear antibody is ≥20 units and <60 units, as measured by an enzyme-linked immunosorbent assay; or
(c) 2, when the level of anti-nuclear antibody ≥60 units, as measured by an enzyme-linked immunosorbent assay;
(iii) log is natural log;
(iv) EC4d is net mean fluorescence intensity of erythrocyte C4d marker, as measured by fluorescence activated flow cytometry;
(v) BC4d is net mean fluorescence intensity of B-cell C4d marker, as measured by fluorescence activated flow cytometry; and
(vi) SpecComp is:
(a) 0, when the level of anti-Sjögren's syndrome type B antigen antibody is ≤10 Units/mL; the level of anti-Scl-70 antibody is ≤10 Units/mL; the level of anti-Jo-1 antibody is ≤10 Units/mL; and the level of anti-centromere protein B antibody is ≤10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(b) 1, when one or more of the level of anti-Sjögren's syndrome type B antigen antibody is >10 Units/mL; the level of anti-Scl-70 antibody >10 Units/mL; the level of anti-Jo-1 antibody is >10 Units/mL; or the level of anti-centromere protein B antibody is >Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(C) identifying the subject as having SLE when the index score is >0; and
(D) treating the subject identified as having SLE in step (C) with an effective amount of hydroxychloroquine.
7. A method of treating systemic lupus erythematosus (SLE) in a subject identified as having SLE, the method comprising:
(A) determining a level of erythrocyte C4d marker, a level of B-cell C4d marker, a level of anti-nuclear antibody, a level of Sjögren's syndrome type B antigen, a level of Scl-70 antibody, a level of Jo-1 antibody, and a level of centromere B protein in a blood sample from the subject;
(B) calculating a systemic lupus erythematosus index score with the levels of erythrocyte C4d marker, B-cell C4d marker, anti-nuclear antibody, Sjögren's syndrome type B antigen, Scl-70 antibody, Jo-1 antibody, and centromere B protein with the equation:
Index=−5.2626+0.9877 ×ANAComp [0.2955×log( EC 4 d )+1.0260×log( BC 4 d )]−2.4944 ×SpecComp;
wherein:
(i) Index is the systemic lupus erythematosus index score;
(ii) ANAComp is:
(a) 0, when the level of anti-nuclear antibody <20 units, as measured by an enzyme-linkedimmunosorbent assay;
(b) 1, when the level of anti-nuclear antibody is ≥20 units and <60 units, as measured by an enzyme-linked immunosorbent assay; or
(c) 2, when the level of anti-nuclear antibody ≥60 units, as measured by an enzyme-linkedimmunosorbent assay;
(iii) log is natural log;
(iv) EC4d is net mean fluorescence intensity of erythrocyte C4d marker, as measured by fluorescence activated flow cytometry;
(v) BC4d is net mean fluorescence intensity of B-cell C4d marker, as measured by fluorescence activated flow cytometry; and
(vi) SpecComp is:
(a) 0, when the level of Sjögren's syndrome type B antigen is ≤10 Units/mL; the level of Scl-70 antibody is ≤10 Units/mL; the level of Jo-1 antibody is ≤10 Units/mL; and the level of centromere B protein is ≤10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(b) 1, when one or more of the level of Sjögren's syndrome type B antigen is >10 Units/mL; the level of Scl-70 antibody >10 Units/mL; the level of Jo-1 antibody is >10 Units/mL; or the level of centromere B protein is >10 Units/mL; where each are as measured by a fluoroenzymatic immunoassay;
(C) identifying the subject as having SLE when the index score is >0; and
(D) treating the subject identified as having SLE in step (C) with an effective amount of a corticosteroid.
8. The method of claim 1 , wherein determining the level of erythrocyte C4d marker comprises determining the level of erythrocyte C4d on the surface of erythrocytes, and wherein determining the level of B-cell C4d marker comprises determining the level of B-cell C4d on the surface of B lymphocytes.
9. The method of claim 2 , wherein determining the level of erythrocyte C4d marker comprises determining the level of erythrocyte C4d on the surface of erythrocytes, and wherein determining the level of B-cell C4d marker comprises determining the level of B-cell C4d on the surface of B lymphocytes.
10. The method of claim 3 , wherein determining the level of erythrocyte C4d marker comprises determining the level of erythrocyte C4d on the surface of erythrocytes, and wherein determining the level of B-cell C4d marker comprises determining the level of B-cell C4d on the surface of B lymphocytes.
11. The method of claim 4 , wherein determining the level of erythrocyte C4d marker comprises determining the level of erythrocyte C4d on the surface of erythrocytes, and wherein determining the level of B-cell C4d marker comprises determining the level of B-cell C4d on the surface of B lymphocytes.
12. The method of claim 5 , wherein determining the level of erythrocyte C4d marker comprises determining the level of erythrocyte C4d on the surface of erythrocytes, and wherein determining the level of B-cell C4d marker comprises determining the level of B-cell C4d on the surface of B lymphocytes.
13. The method of claim 6 , wherein determining the level of erythrocyte C4d marker comprises determining the level of erythrocyte C4d on the surface of erythrocytes, and wherein determining the level of B-cell C4d marker comprises determining the level of B-cell C4d on the surface of B lymphocytes.
14. The method of claim 7 , wherein determining the level of erythrocyte C4d marker comprises determining the level of erythrocyte C4d on the surface of erythrocytes, and wherein determining the level of B-cell C4d marker comprises determining the level of B-cell C4d on the surface of B lymphocytes.