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The hyperimmunoglobulinemia D and periodic fever (hyper-IgD) syndrome is typified by recurrent febrile attacks with abdominal distress, joint involvement (arthralgias/arthritis), headache, skin lesions, and an elevated serum IgD level (> 100 U/mL). This familial disorder has been diagnosed in 59 patients, mainly from Europe. The pathogenesis of this febrile disorder is unknown, but attacks are joined by an acute-phase response. Because this response is considered to be mediated by cytokines, we measured the acute-phase proteins C-reactive protein (CRP) and soluble type-II phospholipase A2 (PLA2) together with circulating concentrations and ex vivo production of the proinflammatory cytokines interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-6, and tumor necrosis factor alpha (TNF alpha) and the inhibitory compounds IL-1 receptor antagonist (IL-1ra), IL-10, and the soluble TNF receptors p55 (sTNFr p55) and p75 (sTNFr p75) in 22 patients with the hyper-IgD syndrome during attacks and remission. Serum CRP and PLA2 concentrations were elevated during attacks (mean, 213 mg/L and 1,452 ng/mL, respectively) and decreased between attacks. Plasma concentrations of IL-1 alpha, IL-1 beta, or IL-10 were not increased during attacks. TNF alpha concentrations were slightly, but significantly, higher with attacks (104 v 117 pg/mL). Circulating IL-6 values increased with attacks (19.7 v 147.9 pg/mL) and correlated with CRP and PLA2 values during the febrile attacks. The values of the antiinflammatory compounds IL-1ra, sTNFr p55, and sTNFr p75 were significantly higher with attacks than between attacks, and there was a significant positive correlation between each. The ex-vivo production of TNF alpha, IL-1 beta, and IL-1ra was significantly higher with attacks, suggesting that the monocytes/macrophages were already primed in vivo to produce increased amounts of these cytokines. These findings point to an activation of the cytokine network, and this suggests that these inflammatory mediators may contribute to the symptoms of the hyper-IgD syndrome.

Plasma cells isolated from bone marrow (BM) aspirates of 12 patients with multiple myeloma (MM) and nine patients with monoclonal gammopathy of undetermined significance (MGUS) were analyzed for production of cytokines with bone-resorbing activity, such as interleukin-1 (IL-1), tumor necrosis factor (TNF), and lymphotoxin (LT). Culture supernatants of plasma cells from MM, but not from MGUS or normal donor, invariably contained high amounts of IL-1-beta and lower amounts of IL-1-alpha. With a single exception, TNF/LT biologic activity was not detected in the same supernatants. IL-6 was present in two of five supernatants tested. Normal B lymphocytes released both IL-1 and TNF/LT activities for four days after activation in vitro; however, production of these cytokines ceased at the final stage of plasma cell. Unexpectedly, the mRNA extracted from MM plasma cell hybridized with TNF- and LT-specific, as well as IL-1-specific probes, although the culture supernatants did not contain detectable TNF/LT biologic activity. When tested in the fetal rat long bone assay, MM plasma cell supernatants displayed a strong osteoclast-activating factor (OAF) activity, which was greatly reduced but not completely abolished by neutralizing anti-IL-1 antibodies. Anti-TNF or anti-LT antibodies were ineffective in the same test. We conclude that the IL-1 released in vivo by malignant plasma cells has a major role in pathogenesis of lytic bone lesions of human MM.