An unknown antigen presented by the major histocompatibility complex (MHC) class II molecules causes T cells to become autoreactive (Fig. 29-1). Once activated, T cells penetrate the blood-brain barrier by attachment to upregulated adhesion molecules and production of matrix metalloproteinases (MMP) that cause blood-brain barrier breakdown. In the CNS, the T cells come into contact with antigen-presenting cells (APCs) and proliferate. The T-helper cells differentiate into proinflammatory T-help-er-1 cells (Th1 cells) and anti-inflammatory T helper-2 cells (Th2 cells).8 Th1 cells secrete cytokines that enhance macrophage and microglial cells that attack myelin.8

B cells cross previously damaged sections of the blood-brain barrier to arrive in the CNS, an area normally free of B cells. Autoreactive T cells trigger B cells to form myelin autoantibodies. B-cell antibodies also initiate the complement cascade, causing myelin degradation.8 These inflammatory processes probably cause relapses.5

How To Deal With Rosacea and Eczema

How To Deal With Rosacea and Eczema

Rosacea and Eczema are two skin conditions that are fairly commonly found throughout the world. Each of them is characterized by different features, and can be both discomfiting as well as result in undesirable appearance features. In a nutshell, theyre problems that many would want to deal with.

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