Thrombocytosis in Systemic Lupus Erythematosus: A Possible Clue to Autosplenectomy?

GABRIELLA CASTELLINO, MARCELLO GOVONI, NAPOLEONE PRANDINI, GESSICA LIMPIDO, SIMONE BERNARDI, DIANA CAMPIONE, FRANCESCO LANZA, and FRANCESCO TROTTA

ABSTRACT.

Objective. Thrombocytosis can be due to a myeloproliferative disorder or to a reactive or secondary process; among these are connective tissue disorders, in particular systemic lupus erythematosus (SLE). Besides being an expression of active disease, this unusual finding has also been described in SLE complicated by autosplenectomy. We evaluated the prevalence of thrombocytosis in a series of SLE patients and its relationship to functional asplenia.

Methods. Platelet count was evaluated in 465 consecutive Caucasian patients with SLE (387 women, 78 men, median age 54 yrs). Thrombocytosis was defined as platelet count > 400 ´ 10⁹/l in at least 3 blood samples. All patients with thrombocytosis underwent peripheral blood smears for erythrocyte abnormalities and instrumental spleen evaluation.

Results. Seventeen patients (3.7%) with thrombocytosis were observed. Peripheral blood smear showed Howell-Jolly bodies, spherocytes, and target cells in 3/17 patients (17.6%). In the same 3 patients, ultrasound and computed tomography failed to evidence the spleen, and liver-spleen scans showed absence of splenic uptake (a finding indicative of functional autosplenectomy). One satisfied criteria for antiphospholipid syndrome (APS), and the other 2 patients had positive IgG antiphospholipid antibodies (aPL) at medium titer.

Conclusion. The sudden appearance and persistence of thrombocytosis or even the apparent reversal of thrombocytopenia in patients with SLE should raise suspicion of autosplenectomy, in particular if secondary APS or aPL is present. (First Release June 1 2007; J Rheumatol 2007;34:1497–501)

Key Indexing Terms:

SYSTEMIC LUPUS ERYTHEMATOSUS
THROMBOCYTOSIS
AUTOSPLENECTOMY
ANTIPHOSPHOLIPID ANTIBODIES

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From the Unità Operativa di Reumatologia, Unitá Operativa di Ematologia and Servizio di Medicina Nucleare, Università degli Studi di Ferrara, and Azienda Ospedaliera–Universitaria "Arcispedale S. Anna," Ferrara, Italy.

G. Castellino, MD, Unitá Operativa di Ematologia; M. Govoni, MD, Associate Professor; G. Limpido, MD, Fellow in Rheumatology; S. Bernardi, MD, Fellow in Rheumatology; F. Trotta, MD, Professor of Rheumatology, Chief, Rheumatology Unit, Department of Clinical and Experimental Medicine, University of Ferrara; N. Prandini, MD, Assistant, Nuclear Medicine Department, Arcispedale S. Anna; D. Campione, Research Fellow; F. Lanza, MD, Assistant, Department of Hematology, Arcispedale S. Anna.

Address reprint requests to Dr. G. Castellino, Rheumatology Unit, Department of Clinical and Experimental Medicine, University of Ferrara, Corso della Giovecca 203, 44100 Ferrara, Italy. E-mail: gabriella_castellino@yahoo.it

Accepted for publication February 26, 2007.

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