Análisis de anticuerpos antifosfolipídicos y cistatina C en pacientes con esclerosis múltiple / Analysis of antiphospholipid antibodies and cystatin C in multiple sclerosis patients / Teste de anticorpos antifosfolípídes e cistatina C em pacientes com esclerose múltipla

La cistatina C es considerada el inhibidor fisiológico más importante de las proteasas de cisteína endógenas. Se cree que el papel de la cistatina C es el de modular la actividad de las proteasas secretadas o liberadas de células dañadas o en proceso de necrosis, siendo por tanto las cistatinas fundamentales para los procesos de regulación y prevención del potencial daño proteolítico local. Los anticuerpos antifosfolípidos se usan para esclarecer el diagnóstico de esclerosis múltiple (EM) ya que existen patologías que pueden cursar con sintomatología o hallazgos paraclínicos semejantes. El objetivo de este trabajo fue analizar la concentración de cistatina C y la presencia o ausencia de anticuerpos antifosfolipídicos en pacientes diagnosticados de esclerosis múltiple remitente recurrente (EMRR) como marcadores de desmielinización. Este trabajo se llevó a cabo conjuntamente por el laboratorio de Riesgo Vascular, el laboratorio de Autoinmunidad y la Unidad de Esclerosis Múltiple del Hospital Universitario Virgen Macarena de Sevilla, España, con una duración de un año. Se seleccionaron dos tipos de poblaciones: grupo 1, n=30 pacientes con EMRR y un segundo grupo, denominado grupo control, n=30. Se determinó cistatina C y anticuerpos antifosfolípidos IgG e IgM, anticuerpos anticardiolipina IgG e IgM y anticuerpos f>2 glicoproteína IgG e IgM. Los pacientes diagnosticados de EMRR presentan títulos negativos de anticuerpos antifosfolípidos IgG e IgM, anticardiolipina IgG e IgM y f>2 glicoproteína IgG e IgM. La concentración de cistatina C es menor en el grupo de pacientes diagnosticados de EM, lo que podría producir un déficit en la modulación de las proteasas de cisteína endógenas. Dicha desmielini-zación agudizaría el progreso de la EM.

Cystatin C is considered the most important physiological inhibitor of endogenous cysteine proteases; the role of cystatin C is believed to be to modulate the activity of proteases secreted or released from damaged cells or in the process of necrosis, therefore cystatins being fundamental regulatory processes and a potential prevention of local proteolytic damage. Antiphospholipid antibodies are used to clarify the diagnosis of diseases like multiple sclerosis (MS) and other pathologies could present similai symptoms or paraclinical findings. The objective of the present work is to analyze the concentration of cystatin C and the presence or absence of antiphospholipid antibodies in patients diagnosed with relapsing remitting multiple sclerosis (RRMS) as markers of demyelization. This work was carried out jointly by the Vascular Risk Laboratory, the Laboratory of Autoimmunity and Multiple Sclerosis Unit, Hospital Universitario Virgen Macarena in Seville in one year. Two types of people were selected: Group 1 (n = 30) RRMS group and a control group, n = 30. Cystatin C and antiphospholipid antibodies IgG and IgM, IgG and IgM anticardiolipin, $2 glycoprotein IgG and IgM were determined. Patients showed negative titers of antiphospholipid antibodies IgG and IgM, IgG and IgM anticardiolipin, $2 glycoprotein IgG and IgM. Cystatin C concentration is lower in the group of patients diagnosed with MS, which could give rise to a decrease in the modulation of endogenous cysteine proteases. This would exacerbate the progress of demyelization in MS.

A cistatina C é considerada o inibidor fisiológico das proteases de cisteína endógenas mais importante. Acredita-se que o papel da cistatina C é o de modular a atividade de proteases secretadas ou liberadas a partir de células danificadas ou em processo de necrose, sendo por isso as cistatinas fundamentais para os processos de regulagao e prevengao do potencial dano proteolítico local. Anticorpos antifosfolípides sao usados para esclarecer o diagnóstico de EM, visto que existem patologias que podem apresentar sintomas ou achados paraclínicos semelhantes. O objetivo deste trabalho foi o de analisar a concentra-gao de cistatina C e a presenga ou ausencia de anticorpos antifosfolípides em pacientes diagnosticados com esclerose múltipla recidivante - remitente (EMRR) como marcadores de desmielinizagao. Este trabalho foi realizado em conjunto pelo laboratório de Risco Vascular, o laboratório de Autoimunidade e a Unidade de Esclerose Múltipla do Hospital Universitario Virgen Macarena, de Sevilha, Espanha, com uma duragao de um ano. Foram selecionados dois tipos de populagdes-. Grupo 1 (n = 30) pacientes com EMRR e um segundo grupo, chamado de grupo controle, n = 30. Determinou-se cistatina C e anticorpos antifosfolípides IgG e IgM, anticorpos anticardiolipina IgG e IgM, e anticorpos $2 glicoproteína IgG e IgM. Pacientes diagnosticados com EMRR apresentam títulos negativos de anticorpos antifosfolípides IgG e IgM, anticardiolipina IgG e IgM e $2 glicoproteína IgG e IgM. A concentragao de cistatina C é menor no grupo de pacientes diagnosticados com EM, o que poderia produzir um déficit na modulagao das proteases de cisteína endógenas. Tal desmielinizagao agravaría o progresso da EM.

Cysteine proteases in differentiation of embryonic stem cells into neural cells.

Glycosylated mouse cystatin C (mCysC), an endogenous inhibitor of cysteine cathepsin proteases (CP), has been suggested as a cofactor of ß-FGF to induce the differentiation of mouse embryonic stem cells into neural progenitor cells (NPCs). To investigate the possible role of CP in neural differentiation, we treated embryoid bodies (EBs) with (i) E64, an inhibitor of papain-like CP and of calpains, (ii) an inhibitor of cathepsin L (iCatL), (iii) an inhibitor of calpains (iCalp), or (iv) cystatins, and their ability to differentiate into neural cells was assessed. We show that the inhibition of CP induces a significant increase in Pax6 expression in EBs, leading to an increase in the number of nestin-positive cells after 3 days. Fourteen days after E64 treatment, we observed increased numbers of ß-III-tubulin-positive cells, showing greater percentage of immature neurons, and this feature persisted up to 24 days. At this point, we encountered higher numbers of neurons with inward Na(+) current compared with untreated EBs. Further, we show that mCysC and iCatL, but not unglycosylated egg white cystatin or iCalp, increased the numbers of NPCs. In contrast to E64 and iCatL, mCysC did not inhibit CP in EBs and its neural-inducing activity required ß-FGF. We propose that the inhibition of CP induces the differentiation of mouse embryonic stem cells into NPCs and neurons through a mechanism that is distinct from CysC-induced neural differentiation.

Association of cystatin C with adverse outcomes.

PURPOSE OF REVIEW: To discuss recent studies which have evaluated determinants of cystatin C and to focus on the relationship of cystatin C with mortality, cardiovascular disease (CVD), and noncardiovascular outcomes. RECENT FINDINGS: In the Chronic Kidney Disease Epidemiology Study cystatin C was associated with demographic characteristics independent of measured glomerular filtration rate (GFR), although this was to a smaller extent than creatinine. In patients with established chronic kidney disease (CKD), cystatin C was strongly and inversely correlated with measured GFR, suggesting that although cystatin C may have other determinants, it is primarily a measure of kidney function. Several cohort studies, particularly in older adults, have now demonstrated that cystatin C is linearly associated with mortality, CVD and non-CVD outcomes, whereas creatinine is primarily associated with risk in individuals with more advanced kidney disease. A recent study has also shown that changes in kidney function as ascertained by cystatin C, even within the relatively normal range, are associated with subsequent CVD and all-cause mortality among older adults. SUMMARY: Cystatin C appears to capture an association of mild kidney disease with increased risk of mortality, CVD and non-CVD outcomes. Future studies should evaluate whether cystatin C can improve medical decision-making and lead to favorable patient outcomes.