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Systemic lupus erythematosus (SLE) is the classical immune-complex disease. Involvement of vital organs, particularly the kidneys and brain, accounts for significant morbidity and mortality. A number of imaging tools are currently available for evaluation of inflammatory conditions. By targeting the increased glucose uptake of infiltrating granulocytes and tissuemacrophages, positron emission tomographywith fluorine-18 fluorodeoxyglucose ([18F]FDGPET/CT) hasbeen showntodelineateinflammationwith highsensitivity. Because activatedlymphocytes have increased glucose metabolism, [18F]FDG PET has been successfully used to visualize large concentrations of these cells in lymphoid organswhere antigen presentation and lymphocyte activation occur.Widespread increased FDG uptake in lymph nodes of patients with active SLE, as well as increased thymic uptake, has been described. The most prevalent and dramatic PET/CT finding in neuropsychiatric SLE (NP-SLE) patients is parieto-occipital hypometabolism. In conclusion, PET/CT has become an excellent ancillary tool to assess disease activity and prognosis in SLE patients. [ABSTRACT FROM AUTHOR]

Mycophenolate mofetil (MMF) is an immunosuppressive agent initially used in the treatment of transplant recipients. MMF has been used in renal, heart, and liver transplantation, where it seems more effective than other immunosuppressive regimens in reducing the incidence of acute rejection episodes. MMF has a variety of immunosuppressive effects, including selective suppression of T and B lymphocyte proliferation, and has been more recently used in many autoimmune inflammatory conditions. Systemic lupus erythematosus (SLE) is an autoimmune disease that can potentially involve any organ or system of the human body. Glomerulonephritis (GLN) has been recognized as the most frequent severe manifestation of SLE, leading to poor long-term prognosis. In the treatment of lupus GLN, several therapeutic approaches, all including immunosuppressive drugs, such as cyclophosphamide, azathioprine, or cyclosporine A, have been used. The short- and long-term toxicity of these drugs limits their use in a substantial number of patients. Over the last few years, MMF has emerged as an alternative therapeutic regimen in lupus GLN, mainly for patients refractory to other therapies. These studies have shown that it is highly effective and generally well tolerated. [ABSTRACT FROM AUTHOR]

Lupus nephritis (LN) is a major cause of morbidity and mortality in systemic lupus erythematosus (SLE). As the course of LN is often unpredictable, it is important to identify reliable, noninvasive methods to repeatedly assess the condition of the kidneys in these patients. Urinary biomarkers are easily obtained and probably are best at reflecting the current renal status, as they specifically represent local inflammatory activity. In this article, we review a number of potential urinary biomarkers, including Lipocalin-2, MCP-1, IP-10, IL-6, and IL-8. Additionally, we provide evidence for the possible utility of the novel cytokine TWEAK as a urinary biomarker for LN. [ABSTRACT FROM AUTHOR]

Carnitine and its congeners may regulate the immune networks, and their influence on functions of immune cells predominantly or exclusively relies on carnitine-dependent energy production from fatty acids. A reduced pool of carnitines has been demonstrated in either serum or tissues, or both, from patients with a wide spectrum of disorders characterized by unregulated or impaired immune responses ranging from sepsis syndrome to systemic sclerosis, infection with human immunodeficiency virus, and chronic fatigue syndrome. Furthermore, experimental studies have consistently reported that the deranged immune responses and the less efficient inflammation towards infectious organisms associated with aging may be enhanced or modulated by treatment with carnitines. There is also evidence that carnitine deprivation could adversely affect the course of the sepsis syndrome, at least in experimental models, and preliminary studies suggest that carnitine deficiency is ultimately implicated in the pathophysiology of endotoxin-mediated multiple organ failure. Several data indicate that carnitine deficiency is a contributing factor to the progression of infection with human immunodeficiency virus, and carnitine therapy in those patients could counteract the unregulated process of lymphocyte apoptosis and improve CD4 counts. Some case reports have suggested the use of carnitine for the treatment of the severe lactic acidosis that complicates in some patients the use of reverse transcriptase inhibitors. [ABSTRACT FROM AUTHOR]

In acute inflammatory responses, such as wound healing and glomerulonephritis, arginine is the precursor for production of the cytostatic molecule nitric oxide (NO) and the pro-proliferative polyamines. NO is an early phase response whereas increased generation of polyamines is requisite for the later, repair phase response. The temporal switch of arginine as a substrate for the inducible nitric oxide synthase (iNOS)/NO axis to arginase/ornithine decarboxylase (ODC)/polyamine axis is subject to regulation by inflammatory cytokines as well as interregulation by the arginine metabolites themselves. Herein we describe the capacity of another arginine pathway, the metabolism of arginine to agmatine by arginine decarboxylase (ADC), to aid in this interregulation. Agmatine is an antiproliferative molecule due to its suppressive effects on intracellular polyamine levels, whereas the aldehyde metabolite of agmatine is a potent inhibitor of iNOS. We propose that the catabolism of agmatine to its aldehyde metabolite may act as a gating mechanism at the transition from the iNOS/NO axis to the arginase/ODC/polyamine axis. Thus, agmatine has the potential to serve in the coordination of the early and repair phase pathways of arginine in inflammation. [ABSTRACT FROM AUTHOR]