Thrombocytosis in systemic lupus erythematosus: a possible clue to autosplenectomy?
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 x 10(9)/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.


CONCLUSIONS
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.
Castellino
Gabriella
G
Unità Operativa di Reumatologia, Unitá Operativa di Ematologia and Servizio di Medicina Nucleare, Università degli Studi di Ferrara, Azienda Ospedaliera Universitaria Arcispedale S. Anna, Ferrara, Italy. gabriella_castellino@yahoo.it
Govoni
Marcello
M
Prandini
Napoleone
N
Limpido
Gessica
G
Bernardi
Simone
S
Campione
Diana
D
Lanza
Francesco
F
Trotta
Francesco
F
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001284:Atrophy / Q000473:pathology; D001323:Autoantibodies / Q000097:blood; D001327:Autoimmune Diseases / Q000150:complications / Q000473:pathology; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000150:complications* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D013154:Spleen / Q000473:pathology*; D013158:Splenic Diseases / Q000097:blood / Q000150:complications* / Q000473:pathology; D013922:Thrombocytosis / Q000097:blood / Q000209:etiology* / Q000473:pathology
D001323:Autoantibodies