Ab0620 immune Thrombocytopenic Purpura and Subsequent Development of Systemic Lupus Erythematosus

Abstract

BackgroundImmune Thrombocytopenic Purpura (ITP) is an immune-mediated disorder, characterized by isolated thrombocytopenia (<100,000/mm3). It is part of Systemic Lupus Erythematosus (SLE) classification criteria, and may be one of the first manifestations of the disease, often occurring years before its diagnosis.ObjectivesTo assess the incidence of SLE in a cohort of patients with ITP, and to identify predictors for its development.MethodsRetrospective cohort study. We included patients with ITP treated in a University Hospital between 2000 and 2018, with at least one year of follow-up. Patients with SLE or other secondary causes of ITP were excluded. Demographic, clinical, laboratory and treatment data were recorded. Patients meeting SLE classification criteria (ACR 1997/ SLICC 2012) during the follow-up were identified, and incidence density of SLE was calculated. Patients with ITP were grouped according to the development or non-development of SLE, and comparisons were made. Univariate analysis was performed to identify factors associated with the future development of SLE.Results186 patients were included, 64.5% women, with a median age of 27.2 years (IQR 6.3-63.9). After a follow-up of 1801.4 person/years (py), 10 patients (5.4%) developed SLE, with a median time of 22.9 months (IQR 9.8-60.9) between ITP diagnosis and development of SLE. The incidence density of SLE was 5.6/1000 py (95% CI 2.9-9.9/1000 py).Patients who developed SLE had significantly higher proportion of chronic ITP (80% vs 40.3%; p 0.01), lower proportion of complete response (10% vs 54.6%; p 0.006), and more relapses (60% vs 30.6%; p 0.05). The median duration of ITP in SLE patients was significantly longer (67.5 vs 4 months, p<0.001).The presence of ANA (p<0.001), nuclear homogeneous pattern (p<0.001), ANA titres >1/640 (p 0.02), hypocomplementemia (p<0.001), LAC (p<0.001), hypergammaglobulinemia (p<0.001), leukopenia (p 0.006) and hemolytic anemia (p 0.005) were significantly associated with the future development of SLE.ConclusionIn this cohort of ITP patients, the more refractory course of ITP, as well as the presence of high titre - nuclear homogeneous ANA, hypocomplementemia, LAC, hypergammaglobulinemia and other cytopenias were associated with the subsequent development of SLE.Table 1.Baseline characteristics at ITP diagnosis and comparison between groups.ITP developing SLE (n= 10)ITP non-developing SLE (n= 176)pAge, years, median (IQR)19.0 (12.4-31.6)28.3 (5.8-64.5)0.36Female gender, n, (%, 95% CI)9 (90.0, 50.1-98.8)111 (63.1, 55.6-69.9)0.08Follow-up time, years, median (IQR)6.9 (4.9-10.1)10.2 (4.6-14.8)0.49Rheumatologist evaluation at ITP diagnosis, n (%, 95% CI)8 (80.0, 43.6-95.4)23 (13.1, 8.8-18.9)<0.001ANA positivity, n (%, 95% CI)10 (100)35 (30.7, 22.8-39.9)<0.001Hypocomplementemia, n (%, 95% CI)6 (60.0, 27.9-85.3)7 (10.1, 4.8-20.1)<0.001Lupus anticoagulant, n (%, 95% CI)4 (40.0, 14.7-71.9)6 (6.1, 2.7-13.1)<0.001Polyclonal hypergammaglobulinemia, n (%, 95% CI)5 (55.6, 23.4-83.6)14 (11.6, 6.9-18.7)<0.001Splenomegaly, n (%, 95% CI)3 (33.3, 10.2-68.8)17 (12.8, 8.0-19-7)0.09Megakaryocytic hyperplasia in bone marrow, n (%, 95% CI)4 (80.0, 24.9-97.9)47 (64.4, 52.5-74.7)0.48Hemolytic anemia, n (%, 95% CI)1 (10.0, 1.2-49.9)1 (0.6, 0.1-3.9)0.005Leukopenia, n (%, 95% CI)3 (30.0, 9.3-64.3)11 (6.3, 3.5-10.9)0.006Rituximab therapy, n (%, 95% CI)5 (50.0, 21.2-78.8)40 (22.7, 17.1-29.6)0.05Hydroxychloroquine therapy, n (%, 95% CI)7 (70.0, 35.7-90.7)4 (2.3, 0.8-5.9)<0.001Splenectomy, n (%, 95% CI)2 (20.0, 4.6-56.4)15 (8.5, 5.2-13.7)0.22Duration of ITP treatment, months, median (IQR)67.5 (40-113)4 (1-14.5)<0.001Newly diagnosed ITP (<3 months), n (%, 95% CI)1 (10.0, 1.2-49.9)82 (46.6, 39.3-54.1)0.02Persistent ITP (3-12 months), n (%, 95% CI)1 (10.0, 1.2-49.9)23 (13.1, 8.8-18.9)0.78Chronic ITP (>12 months), n (%, 95% CI)8 (80.0, 43.6-95.4)71 (40.3, 33.3-47.8)0.01Figure 1.ANA characteristics at ITP diagnosis.REFERENCES:NIL.Acknowledgements:NIL.Disclosure of InterestsGelsomina Alle: None declared, Marina Scolnik Speakers bureau: GSK, Janssen, Pfizer, Roche, Lilly, Grant/research support from: Janssen, GSK, Valeria Scaglioni: None declared, JOHN FREDY JARAMILLO GALLEGO: None declared, Mayra Alejandra Tobar Jaramillo: None declared, Rodolfo Nicolas Alvarado: None declared, Enrique Soriano Speakers bureau: Amgen, Abbvie, BMS, Eli Lilly, Janssen, Novartis, Pfizer, Sandoz, UCB, Consultant of: Abbvie, Janssen, Pfizer, Amgen, Sandoz, Novartis, Grant/research support from: Novartis, Pfizer, Amgen, Elea, Javier Rosa Speakers bureau: Eli Lilly, AbbVie/Abbott, Bristol-Myers Squibb(BMS), Amgen, Novartis, Pfizer.