Background In our area, SLE patients present haematologic manifestations in approximately 70% of cases1. Some of these manifestations are rare so there are no large series whose analysis can provide relevant information.
Objectives To study the characteristics of patients with thrombotic thrombocytopenic purpura (TTP) in a large sample of SLE patients.
Methods SLE patients from RELESSER database were studied. We analysed the clinical and serological SLE manifestations present at the 9 domains of the British Isles Lupus Assessment Group (BILAG) activity index, all of them before, during and after TTP diagnosis until the last patient's assessment. We also studied activity (SELENA-SLEDAI) and damage (SLICC/ACR DI) indices in each one of those moments.
We evaluated the treatment received, TTP recurrences and the number of deaths by this entity.
Results 3,656 patients from 45 Rheumatology Units across Spain were studied. We found 19 cases of PTT (<1% of total). 100% were women, 94.7% Caucasian. Mean age (±SD) at diagnosis was 28.9±11.4 years.
We divided the patients into 3 groups according to the chronology between diagnosis of TTP and SLE. In group 1 (G1) patients developed TTP and later SLE. In group 2 (G2) patients presented TTP and SLE simultaneously. In group 3 (G3) patients developedSLE and then TTP. According to this classification, 3, 5 and 11 patients were included in each group, respectively.
At the time of TTP diagnosis the patients presented haemoglobin (g/dl) and platelets levels (mean number ± SD): In G1: 10±3.2 and 10,667±7,506; in G2: 7.7±2.1 and 25,200±38,590 and in G3: 7.4±1.8 and 22,909±18,387.
Patients from G2, and particularly from G3, showed high SLE activity at PTT diagnosis (SLEDAI>6). Afterwards the patients maintained SLEDAI scores of 3.8±5.3 at G2 and 2.4±0.7 at G3.
The number of therapy lines and the number of treatments administered was 2.8±2 and 5.4±2.9, respectively in G2, and 2.4±1.7 and 3.8±2.5 in G3, contrasting with G1 where the patients needed only 1 line ±0 of treatment and 2±1 drugs.
The treatment most frecuently received by patients in G1 were glucocorticoids (GC)(100%), in G2 GC (100%), plasma exchange (PE) (80%) and cyclophosphamide (CyC)(60%); in G3 GC (81.8%), PE (72.7%) and CyC (41.8%).
There were only recurrences and deaths in G3, 2 patients in each case.
More detailed results of the analysis in each of the 3 groups are shown in table 1.
Conclusions TTP is a rare event (<1%) in SLE. It can be severe and fatal. Because of this, PTT diagnosis should be suspected in all SLE patients who present anemia and thrombocytopenia and treatment should be started without delay.
Pego-Reigosa JM et al. Analysis of disease activity and response to treatment in a large Spanish cohort of patients with systemic lupus erythematosus. Lupus. 2014. doi:10.1177/0961203314563818.
Disclosure of Interest A. Lois: None declared, I. Rúa: None declared, V. delCampo: None declared, F. Lόpez: None declared, M. Galindo: None declared, J. Calvo: None declared, I. Hernández: None declared, M. Belmonte: None declared, C. Erausquin: None declared, E. Tomero: None declared, R. Blanco: None declared, V. Calvo: None declared, E. Uriarte: None declared, P. Vela: None declared, M. Freire: None declared, J. deToro: None declared, C. Montilla: None declared, E. Raya: None declared, A. Fernández: None declared, L. Horcada: None declared, J. Pego Grant/research support from: Work supported by Spanish Society of Rheumatology, FIS/ISCIII (PI11/02857), BIOCAPS from the EU 7th Framework Programme/REGPOT-2012-2013.1 (316265),GSK, Roche, Novartis,UCB.