Neurotoxic lupus autoantibodies alter brain function through two distinct mechanisms.

Damaging interactions between antibodies and brain antigenic targets may be responsible for an expanding range of neurological disorders. In the case of systemic lupus erythematosus (SLE), patients generate autoantibodies (AAbs) that frequently bind dsDNA. Although some symptoms of SLE may arise from direct reactivity to dsDNA, much of the AAb-mediated damage originates from cross-reactivity with other antigens. We have studied lupus AAbs that bind dsDNA and cross-react with the NR2A and NR2B subunits of the NMDA receptor (NMDAR). In adult mouse models, when the blood-brain barrier is compromised, these NMDAR-reactive AAbs access the brain and elicit neuronal death with ensuing cognitive dysfunction and emotional disturbance. The cellular mechanisms that underlie these deleterious effects remain incompletely understood. Here, we show that, at low concentration, the NMDAR-reactive AAbs are positive modulators of receptor function that increase the size of NMDAR-mediated excitatory postsynaptic potentials, whereas at high concentration, the AAbs promote excitotoxicity through enhanced mitochondrial permeability transition. Other synaptic receptors are completely unaffected by the AAbs. NMDAR activation is required for producing both the synaptic and the mitochondrial effects. Our study thus reveals the mechanisms by which NMDAR-reactive AAbs trigger graded cellular alterations, which are likely to be responsible for the transient and permanent neuropsychiatric symptoms observed in patients with SLE. Our study also provides a model in which local AAb concentration determines the exact nature of the cellular response.

Distribution and characteristics of the certification of rheumatologists in Mexico.

OBJECTIVE: Describe the distribution of adult and pediatric rheumatologists with current certification in Mexico and the factors associated with this distribution. METHODS: The databases of the Mexican Council of Rheumatology and the Mexican College of Rheumatology for 2020 were reviewed. The rate of rheumatologists per 100,000 inhabitants by state of the Mexican Republic was calculated. To find out the number of inhabitants by state, the results of the 2020 population census of the National Institute of Statistics and Geography were consulted. The number of rheumatologists with current certification by state, age, and sex was analyzed. RESULTS: In Mexico, there are 1002 registered adult rheumatologists with a mean age of 48.12 ±â€¯13 years. The male gender prevailed with a ratio of 1.18:1. Ninety-four pediatric rheumatologists were identified with a mean age of 42.25 ±â€¯10.4 years, with a predominance of the female gender with a ratio of 2.2:1. In Mexico City and Jalisco, more than one rheumatologist/100,000 inhabitants were reported in the specialty of adults and only in Mexico City in pediatrics. The current certification is 65%-70% on average and the factors associated with a higher prevalence were younger age, female gender and geographic location. CONCLUSIONS: There is a shortage of rheumatologists in Mexico and in the pediatric area there are underserved regions. It is important that health policies apply measures that allow a more balanced and efficient regionalization of this specialty. Although most rheumatologists have current certification, it is necessary to establish strategies to increase this proportion.

Effects of prasterone on bone mineral density in women with active systemic lupus erythematosus receiving chronic glucocorticoid therapy.

OBJECTIVE: To assess prevention of bone mineral density (BMD) loss and durability of the response during treatment with prasterone in women with systemic lupus erythematosus (SLE) receiving chronic glucocorticoids. METHODS: 155 patients with SLE received 200 mg/day prasterone or placebo for 6 months in a double-blind phase. Subsequently, 114 patients were re-randomized to receive 200 or 100 mg/day prasterone for 12 months in an open-label phase. Primary efficacy endpoints were changes in BMD at the lumbar spine (L-spine) from baseline to Month 6 and maintenance of BMD from Month 6 to 18 for patients who received prasterone during the double-blind phase. RESULTS: In the double-blind phase, there was a trend for a small gain in BMD at the L-spine for patients who received 200 mg/day prasterone for 6 months versus a loss in the placebo group (mean +/- SD, 0.003 +/- 0.035 vs -0.005 +/- 0.053 g/cm(2), respectively; p = 0.293 between groups). In the open-label phase, there was dose-dependent increase in BMD at the L-spine at Month 18 between patients who received 200 versus 100 mg/day prasterone (p = 0.021). For patients who received 200 mg/day prasterone for 18 months, the L-spine BMD gain was 1.083 +/- 0.512% (p = 0.042). There was no overall change in BMD at the total hip over 18 months with 200 mg/day prasterone treatment. The safety profile reflected the weak androgenic properties of prasterone. CONCLUSION: This study suggests prasterone 200 mg/day may offer mild protection against bone loss in women with SLE receiving glucocorticoids. (ClinicalTrials.gov Identifiers NCT00053560 and NCT00082511).

Effect of severe neuropsychiatric manifestations on short-term damage in systemic lupus erythematosus.

OBJECTIVE: To determine the effect of severe neuropsychiatric (SNP) manifestations on short-term damage and the time of their presentation, in young patients with systemic lupus erythematosus (SLE) of short disease duration. METHODS: One hundred thirty patients with SLE, hospitalized because of noninfectious SNP manifestations (n = 65) or other reasons (n = 65) were studied. Clinical information, including SLE characteristics, laboratory test results, treatment, disease activity, and damage, was gathered from the medical chart at 3 different dates: the index hospitalization, the closest visit prior to and one year after hospitalization. RESULTS: Demographic and SLE characteristics were comparable in patients with SNP manifestations and controls, including age at SLE diagnosis, 26.1 +/- 11.0 vs 25.7 +/- 11.2 years (p = 0.84). SNP manifestations developed early during the course of SLE, 2.5 +/- 5.2 years. At the visit prior to the hospitalization, disease activity was mild and similar in both patient groups. During hospitalization, patients who developed SNP manifestations reached higher SLE Disease Activity Index scores than controls (p < 0.0001) and also received more aggressive treatment. One year after the hospitalization, disease activity, treatment, and mortality did not differ between the 2 patient groups; however, the increase in damage was higher among the patients with SNP manifestations than controls [0.95 +/- 0.16 (95% CI 0.64-1.26) vs 0.24 +/- 0.09 (95% CI 0.07-0.41), p < 0.0001]. CONCLUSION: SNP manifestations occur early during the course of SLE and add a significant increase in damage compared to non-NP manifestations.