Regulation of the vasculature: clues from lupus

Atherosclerosis and systemic lupus erythematosus

Large increases in mortality related to premature atherosclerosis with coronary artery disease have been reported in patients with systemic lupus erythematosus (SLE). The current pathogenic hypothesis for atherosclerosis involves not only the classic factors identified in the Framingham study, but also includes chronic inflammation, corticosteroid therapy, excess of traditional risk factors, autoantibodies, immune complexes (containing antibodies to phospholipids, to oxidized low-density lipoproteins, and to endothelial cells), and cytokine-producing activated T cells. Early risk factor intervention and effective control of inflammation should be incorporated into the management of SLE to protect against atherosclerosis.

Emergence of targeted immune therapies for systemic lupus

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease, characterised by flares of rampant inflammation that can threaten, in an unpredictable manner, almost any organ in the body. Current standard of care is largely empiric, involving the use of corticosteroids and toxic immune suppressive agents that are widely acknowledged to have unacceptable side effects for long-term use. Recently, there have been significant advances in understanding the nature of some fundamental immune imbalances underlying the complicated clinical manifestations of SLE. Nevertheless attempts to develop and test more targeted, and potentially safer immune-modulating drugs for lupus have encountered significant obstacles, due to the lack of validated biological markers for disease flare and remission, and difficulties in the clinical assessment of the heterogeneous patients. In support of renewed interest in drug development for lupus, large collaborative groups have formed, and efforts are underway to develop objective biomarkers for SLE as well as to improve the standardisation and reproducibility of clinical outcome measures in multi-centre trials.

Theories of schizophrenia: a genetic-inflammatory-vascular synthesis

BACKGROUND

Schizophrenia, a relatively common psychiatric syndrome, affects virtually all brain functions yet has eluded explanation for more than 100 years. Whether by developmental and/or degenerative processes, abnormalities of neurons and their synaptic connections have been the recent focus of attention. However, our inability to fathom the pathophysiology of schizophrenia forces us to challenge our theoretical models and beliefs. A search for a more satisfying model to explain aspects of schizophrenia uncovers clues pointing to genetically mediated CNS microvascular inflammatory disease.

DISCUSSION

A vascular component to a theory of schizophrenia posits that the physiologic abnormalities leading to illness involve disruption of the exquisitely precise regulation of the delivery of energy and oxygen required for normal brain function. The theory further proposes that abnormalities of CNS metabolism arise because genetically modulated inflammatory reactions damage the microvascular system of the brain in reaction to environmental agents, including infections, hypoxia, and physical trauma. Damage may accumulate with repeated exposure to triggering agents resulting in exacerbation and deterioration, or healing with their removal. There are clear examples of genetic polymorphisms in inflammatory regulators leading to exaggerated inflammatory responses. There is also ample evidence that inflammatory vascular disease of the brain can lead to psychosis, often waxing and waning, and exhibiting a fluctuating course, as seen in schizophrenia. Disturbances of CNS blood flow have repeatedly been observed in people with schizophrenia using old and new technologies. To account for the myriad of behavioral and other curious findings in schizophrenia such as minor physical anomalies, or reported decreased rates of rheumatoid arthritis and highly visible nail fold capillaries, we would have to evoke a process that is systemic such as the vascular and immune/inflammatory systems.

SUMMARY

A vascular-inflammatory theory of schizophrenia brings together environmental and genetic factors in a way that can explain the diversity of symptoms and outcomes observed. If these ideas are confirmed, they would lead in new directions for treatments or preventions by avoiding inducers of inflammation or by way of inflammatory modulating agents, thus preventing exaggerated inflammation and consequent triggering of a psychotic episode in genetically predisposed persons.

Challenges in bringing the bench to bedside in drug development for sle

It is now widely accepted that the current standard of care for systemic lupus erythematosus (SLE) patients is inadequate. There has not been a new medication approved for this disease in thirty years. Attempts to develop and test new drugs have been ongoing since the mid-1990s, but have encountered formidable obstacles. Current models for lupus pathogenesis have provided a theoretical framework for understanding how heterogeneous genetic defects might combine in various ways to increase susceptibility to SLE in different individuals, and could have important implications for new drug development. With the current burst of drug discovery and increased public awareness of SLE, the impetus to overcome these obstacles has never been greater.