Value of MRI of the brain in patients with systemic lupus erythematosus and neurologic disturbance

Our objective was to review the frequency and pattern of signal abnormalities seen on conventional MRI in patients with suspected neuropsychiatric systemic lupus erythematosus (NP-SLE). We reviewed 116 MRI examinations of the brain performed on 85 patients with SLE, (81 women, four men, aged 21-78 years, mean 40.6 years) presenting with neurological disturbances. MRI was normal or nearly normal in 34%. In 60% high-signal lesions were observed on T2-weighted images, frequently in the frontal and parietal subcortical white matter. Infarct-like lesions involving gray and white matter were demonstrated in 21 of cases. Areas of restricted diffusion were seen in 12 of the 67 patients who underwent diffusion-weighted imaging. Other abnormalities included loss of brain volume, hemorrhage, meningeal enhancement, and bilateral high signal in occipital white-matter. The MRI findings alone did not allow us to distinguish between thromboembolic and inflammatory events in many patients. Some patients with normal MRI improved clinically while on immunosuppressive therapy. More sensitive and/or specific imaging methods, such as spectroscopy and perfusion-weighted imaging, should be investigated in these subgroups of patients with suspected NP-SLE.

Immunosuppressive drug treatment

Use of the immunosuppressive agents in patients with rheumatic diseases is becoming increasingly common as our experience using these agents increases. This year's review of recent reports on immunosuppressive drugs for rheumatic diseases focuses on recent contributions to the literature regarding individual agents. Additionally, we review recommendations regarding immunization of immunosuppressed patients and exposure of such patients to common communicable illnesses to which they may be inadvertently exposed.

Chronic rubella vaccine-associated arthropathy

Rubella immunization or infection is an uncommonly recognized cause of acute, recurrent, or persistent musculoskeletal manifestations. After routine rubella immunization, two women presented with the onset of polyarthralgia, arthritis, maculopapular rash, fever, paresthesia, and malaise with persistent or recurrent manifestations lasting longer than 24 months after vaccination. The patients expressed rubella virus RNA in peripheral-blood leukocytes 10 and 8 months after vaccination, respectively, in contrast to repeated negative results in asymptomatic rubella-immunized controls. One patient developed significantly depressed antibody responses to rubella virus after vaccination and experienced a prolonged clinical improvement after a 3-month course of intravenous immune globulin. The second patient had normal antibody responses to rubella virus and underwent no clinical improvement during or after intravenous immune globulin therapy. Rubella immunization or infection should be considered as additional causative factors in evaluation of acute and continuing musculoskeletal syndromes.

The SCID-hu mouse: a small animal model for HIV infection and pathogenesis

The SCID-hu mouse is a heterochimeric small animal model designed to support hematopoietic differentiation and function in vivo. Multiple organs of the human hematolymphoid system have been successfully engrafted into the immunodeficient C.B-17 scid scid mouse, including fetal liver, thymus, lymph node, and skin. Co-implantation of human fetal liver and human fetal thymus results in long-term, multilineage human hematopoiesis in vivo. Mature human lymphocytes within the SCID-hu mouse are phenotypically and functionally normal. HIV infection of the SCID-hu mouse reflects a tropism similar to that found in humans: only human organs with CD4+ cells are infected. Viral replication can thereafter be monitored with assays that are safe, reproducible, and quantitative. Given this small animal model, it is now possible to study systematically the infective process of HIV and to address questions about the efficacy of novel antiviral compounds or vaccines in vivo.