Belimumab for SLE, Rituximab and Toxoplasmosis, and "Incidentaloporosis"

Last week's articles on rheumatology topics in the major nonspecialty journals

Systemic lupus erythematosus

Belimumab for Systemic Lupus ErythematosusN Engl J Med, April 18, 2013. Full text $15

NOW@NEJM: Belimumab for SLEN Engl J Med, April 19th, 2013 Free full text.

“Standard treatment” for systemic lupus erythematosus (SLE) is a matter of clinical judgment, and there are no guidelines for using belimumab in SLE. So Bevra Hahn MD of the University of California Los Angeles describes her own practice in a review. Patients who expect dramatic results are often disappointed.Patients expect dramatic results and are often disappointed with an incremental response. Monthly infusions are inconvenient, with a 1% risk of significant infusion reactions, but overall serious adverse effects were similar to placebo.

In her experience, after six months about one-third of patients show a response, one-third discontinue because of adverse effects, and one-third have neither response nor adverse effects. Some patients have a sustained response after discontinuing treatment.Monthly infusions are inconvenient, with a 1% risk of significant infusion reactions, but overall serious adverse effects were similar to placebo.

After only two years of use, she says, there are unanswered questions: Should belimumab be used as a first immunosuppressive agent? How should it be used in combination therapy? Can it be used in central nervous system disease or active lupus nephritis?


Rituximab adverse effects

Cerebral Toxoplasmosis After Rituximab TherapyJAMA Intern Med. Published online April 15, 2013. Full text $30

Commentary: Balancing the Risks and Benefits of RituximabJAMA Intern Med. Published online April 15, 2013, full text $30

A 71-year-old woman with skin ulcers on her legs, diagnosed with cutaneous necrotizing vasculitis associated with type I essential cryoglobulinemia, was treated successfully with rituximab but presented with signs of cerebral toxoplasmosis four months later. Serology suggested reactivation of a previous infection. The authors urge screening patients for Toxoplasma beore initiating rituximab. The  commentary addresses the difficult balance between the effectiveness of rituximab for rheumatoid arthritis (and non-Hodgkin lymphoma), and the 1% incidence of serious infections including numerous pathogens other than Toxoplasma.


Osteoporosis

Opportunistic Screening for Osteoporosis Using Abdominal Computed Tomography Scans Obtained for Other IndicationsAnn Intern Med, April 16, 2013.  Full text $20

Editorial: Conventional Computed Tomography Imaging and Bone Mineral Density: Opportunistic Screening or “Incidentaloporosis”? Ann Intern Med, April 16, 2013.  Full text $20

Abdominal computed tomography (CT) images obtained for other reasons that include the lumbar spine can be used to identify patients with osteoporosis or normal bone mineral density (BMD) without additional radiation exposure or cost, judging from this decade-long study of 1,867 adults who  had both CT and dual-energy x-ray absorptiometry (DXA) within six months of each other for numerous indications. CT attenuation was significantly lower for patients with DXA-defined osteoporosis, and the authors specify attenuation thresholds that are 90% sensitive and 90% specific in identifying osteoporosis. The commentators in the editorial are convinced, pointing to the "fundamental problem" in osteoporosis: underdiagnosis due to undertesting.