Castleman's disease is an atypical
lymphoproliferative disorder characterized by the prevalence of B CD5-positive cells in the marginal zone. Autoimmune manifestations have often been reported, but the association of
Castleman's disease with systemic autoimmune syndromes has been rarely described. However, many authors stress the difficulties in distinguishing between
connective tissue disease and
Castleman's disease in most cases. To clarify this issue, we describe a patient and review the literature reports of all cases of
Castleman's disease associated with a
connective tissue disease. A 19-year old woman presented with
autoimmune thyroiditis and
polymyositis. Seven years after the onset she developed a systemic inflammatory flare and a burst of autoimmunity, followed by generalized lymphoadenopathy. A mediastinal lymph node biopsy led to the diagnosis of
Castleman disease of mixed type.
Chemotherapy was given, with rapid response of the
lymphoproliferative disorder but persistence of the underlying autoimmune disorder. The plasma concentration of
B-lymphocyte stimulator (BLyS) was high (13.3 ng/mL) at the diagnosis of
Castleman's disease. It fell dramatically after
chemotherapy (4.97 ng/mL), even though it remained just above the mean BLyS value found in healthy blood donors (3.37+/-0.78 ng/mL).
Castleman's disease can present autoimmune traits. In our patient,
Castleman's disease complicated the course of a connective tissue disorder several years after the onset. We hypothesize that chronic stimulation of B-cell clones, particularly CD5+, by BLyS could favor the development of both
autoimmune diseases and a broad range of
lymphoproliferative disorders (such as
Castleman's disease). This is the first report of increased BLyS levels in a patient with
Castleman's disease, supporting a possible pathogenetic role of BLyS in the development of an autoimmune disorder and of a B
lymphoproliferative disorder years later.