Tuberculosis in the era of anti-TNF-alpha therapy: Why does the risk still exist? / La tuberculosis en la era del tratamiento con fármacos inhibidores del factor de necrosis tumoral alfa: ¿por qué persiste el riesgo?

Abstract Rheumatoid arthritis is an autoimmune systemic disease characterized mainly by inflammatory compromise of diarthrodial joints. Multiple drug therapies have been developed to control the activity of rheumatoid arthritis, among them, the first line of disease-modifying antirheumatic drugs (DMARD), and novel drug therapies such as the anti-TNF alpha therapy, with satisfactory clinical outcomes. Despite this positive fact, the use of this therapy implies the risk of producing negative effects due to its mechanism of action, which has been associated with multiple infections, especially tuberculosis, making it necessary to use screen tests before resorting to this kind of drugs. We present the case of a 58-year-old female patient, with a six-year history of rheumatoid arthritis. The patient developed disseminated tuberculosis with compatible radiological and histological findings after receiving treatment with infliximab (anti-TNF therapy). No test was performed to screen for latent tuberculosis infection prior to the administration of infliximab. The performance of routine screenings tests for tuberculosis prior to anti-TNF alpha therapy plays an essential role in the detection of asymptomatic patients with latent tuberculosis. This is the only way to identify those patients who would benefit from anti-tuberculosis drugs before the initiation of anti-TNF alpha therapy, which makes the difference in the search of a significant reduction in the incidence of tuberculosis and its associated morbidity and mortality.

Resumen La artritis reumatoidea es una enfermedad crónica de carácter autoinmunitario caracterizada principalmente por el compromiso inflamatorio de las articulaciones cartilaginosas. Se han desarrollado múltiples tratamientos farmacológicos para controlar el avance de la artritis reumatoidea, entre ellos, los fármacos antirreumáticos modificadores de la enfermedad, además de nuevos esquemas terapéuticos con inhibidores del factor de necrosis tumoral alfa, con resultados clínicos satisfactorios. Sin embargo, el uso de tales medicamentos no resulta inocuo, ya que se los ha asociado con diversos efectos secundarios, especialmente, infecciones como la tuberculosis, lo cual exige la aplicación de pruebas de tamización antes de utilizarlos. Se reporta el caso de una paciente de 58 años de edad con artritis reumatoidea de seis años de evolución, que después de recibir tratamiento con uno de estos fármacos, el infliximab, desarrolló tuberculosis diseminada, cuyo diagnóstico se confirmó mediante radiología e histopatología. No se emplearon pruebas de detección de la tuberculosis latente antes de prescribirle el infliximab. Las pruebas de tamización para tuberculosis deben emplearse de forma rutinaria, con el fin de detectar aquellos pacientes con tuberculosis latente, ya que es la única manera de determinar si se requiere profilaxis antituberculosa antes de administrar dichos fármacos, hecho que marca la diferencia cuando se busca disminuir la incidencia de tuberculosis y la consecuente morbimortalidad.

Chloroquine inhibits viability of renal carcinoma cells and enhances sunitinib-induced caspase-dependent apoptosis / 北京大学学报(医学版)

OBJECTIVE@#To determine whether chloroquine (CQ), an often used inhibitor of late autophagy and autophagosome/lyosome fusion, can inhibit proliferation of renal carcinoma cells and investigate its effect on sunitinib (ST)-induced apoptosis.@*METHODS@#Renal carcinoma cell line 786 O and ACHN had been used as cellular model and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay was carried out to detect the cell viability in response to CQ or ST treatment. Both transmission electron microscope and immunoblotting had been employed to observe apoptotic and autophagic process. To examine the involvement of autophagy in ST-dependent apoptosis, autophagy had been inhibited either chemically or genetically via utilizing autophagy inhibitor or specific small interference RNA (siRNA) targeted to either Ulk1 (unc-51-like kinase 1) or LC3 (microtubule associated protein 1 light chain 3 fusion protein), two essential autophagic proteins.@*RESULTS@#Both ST and CQ induced cell viability loss, indicating that either of them could inhibit renal cancer cell proliferation. Clone formation experiments confirmed the aforementioned results. Furthermore, the combined ST with CQ synergistically promoted the loss of cell viability. By transmission electron microscopy and immunoblotting, we found that the ST induced both autophagy and caspase-dependent apoptosis. While 3-MA, an early autophagy inhibitor, reduced the ST-induced cleavage of poly (ADP-ribose) polymerase-1 (PARP-1), a substrate of caspase 3/7 and often used marker of caspase-dependent apoptosis, CQ promoted the ST-dependent PARP-1 cleavage, indicating that the early and late autophagy functioned differentially on the ST-activated apoptotic process. Moreover, the knock down of either Ulk1 or LC3 decreased the ST-caused apoptosis.Interestingly, we observed that rapamycin, a specific inhibitor of mTOR (mammalian target of rapamycin) and an inducer of autophagy, also showed to inhibit cell viability and increased the cleavage of PARP-1 in the ST-treated cells, suggesting that autophagy was likely to play a dual role in the regulation of the ST-induced apoptosis.@*CONCLUSION@#ST activates both apoptotic and autophagic process in renal carcinoma cells. Although autophagy precedes the ST-induced apoptosis, however, early and late autophagy functions differentially on the apoptotic process induced by this compound. Additionally, ST can coordinate with the inducer of autophagy to inhibit the cell proliferation. Further research in this direction will let us illuminate to utilize CQ as a potential drug in the treatment of renal carcinoma.

Correlation between cellular expression of complement regulatory proteins with depletion and repopulation of B-lymphocytes in peripheral blood of patients with rheumatoid arthritis treated with rituximab / Correlação entre expressão celular de proteínas reguladoras do complemento com a depleção e repopulação de linfócitos B no sangue periférico de pacientes com artrite reumatoide tratada com rituximabe

Abstract Objectives: To correlate the basal expression of complement regulatory proteins (CRPs) CD55, CD59, CD35, and CD46 in B-lymphocytes from the peripheral blood of a cohort of 10 patients with rheumatoid arthritis (RA) initiating treatment with rituximab (RTX) with depletion and time repopulation of such cells. Methods: Ten patients with RA received two infusions of 1 g of RTX with an interval of 14 days. Immunophenotypic analysis for the detection of CD55, CD59, CD35, and CD46 on B-lymphocytes was carried out immediately before the first infusion. The population of B-lymphocytes was analyzed by means of basal CD19 expression and after 1, 2, and 6 months after the infusion of RTX, and then quarterly until clinical relapse. Depletion of B-lymphocytes in peripheral blood was defined as a CD19 expression <0.005 × 109/L. Results: Ten women with a median of 49 years and a baseline DAS28 = 5.6 were evaluated; 9 were seropositive for rheumatoid factor. Five patients showed a repopulation of B-lymphocytes after 2 months, and the other five after 6 months. There was a correlation between the basal expression of CD46 and the time of repopulation (correlation coefficient = −0.733, p = 0.0016). A similar trend was observed with CD35, but without statistical significance (correction coefficient = −0.522, p = 0.12). Conclusion: The increased CD46 expression was predictive of a faster repopulation of B-lymphocytes in patients treated with RTX. Studies involving a larger number of patients will be needed to confirm the utility of basal expression of CRPs as a predictor of clinical response.

Resumo Objetivos: Correlacionar a expressão basal das proteínas reguladoras do complemento (PRC) CD55, CD59, CD35 e CD46 nos linfócitos B do sangue periférico de uma coorte de 10 pacientes com artrite reumatoide (AR) iniciando tratamento com rituximabe (RTX) com a depleção e tempo de repopulação dessas células. Métodos: Dez pacientes com AR receberam duas infusões de 1 g de RTX com intervalo de 14 dias. Análises imunofenotípicas para detecção de CD55, CD59, CD35 e CD46 nos linfócitos B foram feitas imediatamente antes da primeira infusão. A população de linfócitos B foi analisada por meio da expressão de CD19 basal e após um, dois e seis meses após a infusão de RTX e então trimestralmente até a recaída clínica. Depleção de linfócitos B no sangue periférico foi definida como expressão de CD19 < 0,005 × 109/l. Resultados: Dez mulheres com mediana de 49 anos e DAS 28 basal de 5,6 foram avaliadas; nove eram soropositivas para o fator reumatoide. Cinco pacientes apresentaram repopulação de linfócitos B após dois meses e as outras cinco aos seis meses. Houve correlação entre a expressão basal de CD46 e o tempo de repopulação (coeficiente de correlação -0,733, p = 0,0016). Tendência semelhante foi observada com CD35, porém sem significância estatística (coeficiente de correção 0,522, p = 0,12). Conclusão: Expressão aumentada de CD46 foi preditora de repopulação mais rápida de linfócitos B em pacientes tratados com RTX. Estudos com um número maior de pacientes serão necessários para confirmar a utilidade da expressão basal das PRC como preditora de resposta clínica.

Protective effects of tumor necrosis factor-α blockade by adalimumab on articular cartilage and subchondral bone in a rat model of osteoarthritis

We aimed to investigate the effects of an anti-tumor necrosis factor-α antibody (ATNF) on cartilage and subchondral bone in a rat model of osteoarthritis. Twenty-four rats were randomly divided into three groups: sham-operated group (n=8); anterior cruciate ligament transection (ACLT)+normal saline (NS) group (n=8); and ACLT+ATNF group (n=8). The rats in the ACLT+ATNF group received subcutaneous injections of ATNF (20 μg/kg) for 12 weeks, while those in the ACLT+NS group received NS at the same dose for 12 weeks. All rats were euthanized at 12 weeks after surgery and specimens from the affected knees were harvested. Hematoxylin and eosin staining, Masson's trichrome staining, and Mankin score assessment were carried out to evaluate the cartilage status and cartilage matrix degradation. Matrix metalloproteinase (MMP)-13 immunohistochemistry was performed to assess the cartilage molecular metabolism. Bone histomorphometry was used to observe the subchondral trabecular microstructure. Compared with the rats in the ACLT+NS group, histological and Mankin score analyses showed that ATNF treatment reduced the severity of the cartilage lesions and led to a lower Mankin score. Immunohistochemical and histomorphometric analyses revealed that ATNF treatment reduced the ACLT-induced destruction of the subchondral trabecular microstructure, and decreased MMP-13 expression. ATNF treatment may delay degradation of the extracellular matrix via a decrease in MMP-13 expression. ATNF treatment probably protects articular cartilage by improving the structure of the subchondral bone and reducing the degradation of the cartilage matrix.

Interações medicamentosas: uma contribuição para o uso racional de imunossupressores sintéticos e biológicos / Drug interactions: a contribution to the rational use of synthetic and biological immunosuppressants

Interação medicamentosa é um evento clínico em que os efeitos de um fármaco são alterados pela presença de outro fármaco, fitoterápico, alimento, bebida ou algum agente químico ambiental. A incidência de reações adversas causadas por interações medicamentosas é desconhecida. Contribui para esse desconhecimento o fato de não se saber o número de pacientes aos quais foram e são prescritas as combinações de medicamentos com potencial para interações. Não é possível distinguir claramente quem irá ou não experimentar uma interação medicamentosa adversa. Possivelmente, pacientes com múltiplas doenças, com disfunção renal ou hepática e aqueles que fazem uso de muitos medicamentos são os mais suscetíveis. Dentre as condições que colocam os pacientes em alto risco para interações medicamentosas está o grupo de portadores de doenças autoimunes. Além de apresentarem um risco para o paciente e um insucesso para o profissional da saúde, as interações medicamentosas podem aumentar muito os custos da saúde. O objetivo desta revisão é abordar as interações clinicamente importantes das drogas mais usadas em reumatologia (exceto os anti-inflamatórios não esteroide e corticosteroides) com o intuito de auxiliar os prescritores reumatologistas no desafio de intervir farmacologicamente nos processos de doença, buscando melhores desfechos para os pacientes e menores gastos com a complexa terapêutica das doenças crônicas sob sua responsabilidade.

Drug interaction is a clinical event in which the effects of a drug are altered by the presence of another drug, phytochemical drug, food, beverage, or any environmental chemical agent. The incidence of adverse reactions caused by drug interactions is unknown. This lack of information is compounded by not knowing the number of patients who are prescribed combinations of drugs that can potentially interact. Patients who will or will not experience an adverse drug interaction cannot be clearly identified. Those with multiple diseases, with kidney or liver dysfunction, and those on many drugs are likely to be the most susceptible. Patients with autoimmune diseases are at higher risk for drug interactions. In addition to representing a risk for the patient and jeopardizing the health care provided by professionals, drug interactions can increase dramatically health care costs. This review article approached the clinically relevant interactions between the most used drugs in rheumatology (except for non-steroidal anti-inflammatories and corticosteroids) aiming at helping rheumatologists to pharmacologically interfere in the disease processes, in the search for better outcomes for patients and lower costs with the complex therapy of chronic diseases they deal with.

Rosette formation by macrophages with adhered T lymphocytes is precluded by inhibitors of antigen processing and presentation

We had previously found in autologous human leukocyte cultures, in which dead neutrophils phagocytosis by macrophages occur, macrophages and T CD4 lymphocytes perform a selective cell-cell interaction showing many figures of either one, two or several T- lymphocytes adhering to a central macrophage were seen. Considering that antigen presentation would be necessary for the formation of these immune synapses, we attempted to block rosette formation (i.e., the formation of macrophage associations with at least three lymphocytes) by interfering with both antigen processing and presentation. Culture samples of autologous leukocytes from 7 healthy donors were subjected to either brefeldin A, chloroquine or to an anti-HLA DR antibody. Rosette formation was significantly inhibited in the treated samples (either with brefeldin A, chloroquine or the anti- HLA DR; ANOVA, p<0.001, as compared with the untreated controls). It is concluded that interference with antigen processing and presentation precludes the formation of these cell-cell interactions.

Mecanismos de acción de los fármacos inmunosupresores / Mechanisms of action of immunosuppressive drugs

Durante los últimos 50 años, muchos fármacos inmunosupresores han sido descritos, y sus mecanismos de acción se pueden dividir en: Reguladores de la expresión génica; Agentes alquilantes; Inhibidores de novo de la síntesis de purinas y pirimidinas, e Inhibidores de quinasas y fosfatasas. Los glucocorticoides ejercen su acción inmunosupresora y antiinflamatoria principalmente mediante la inhibición de la expresión de los genes de interleuquina-2 (IL-2) y otros mediadores. Los metabolitos derivados de Ciclofosfamida alquilanizan las bases de ADN y suprimen preferentemente la respuesta inmune (RI) mediada por linfocitos B (LB). Por su parte, el Metotrexato reprime las respuestas inflamatorias liberando adenosina; ésta induce la apoptosis de LT activos e inhibe la síntesis de purinas y pirimidinas. La Azatioprina inhibe varias enzimas implicadas en la síntesis de purinas, mientras que el Ácido micofenólico inhibe la inosina-monofosfato deshidrogenasa, con lo que agota los nucleótidos derivados de guanosina, induciendo la apoptosis de LT activados. Un metabolito de la Leflunomida suprime la dihidro-orotatedeshidrogenada y, consecuentemente, la síntesis de nucleótidos pirimidínicos. La Ciclosporina y el Tacrolimus inhiben la actividad de la Calcineurina, con lo que se suprime la producción de IL-2 y de otras citoquinas. Además, estos compuestos han demostrado bloquear las vías de señalización JNK y p38, activadas por el reconocimiento de antígenos en LT. Por el contrario, la Rapamicina inhibe quinasas celulares necesarias para el ciclo celular y las respuestas a IL-2; también induce la apoptosis de LT activos. Un futuro promisorio es derivado de la aplicación de fármacos inmunosupresores biológicos. El papel y mecanismos de acción de ellos serán discutidos aquí.

During the past 50 years, many immunosuppressive drugs have been described and their mechanisms of action can be organized in: Regulators of gene expression; Alkylating agents; Inhibitors of the novo purine and pyrimidine synthesis, and Inhibitors of kinases and phosphatases. Glucocorticoids exert immunosuppressive and anti-inflammatory activity mainly by inhibiting the expression of interleukin-2 (IL-2) genes and other mediators. Cyclophosphamide metabolites alkylate DNA bases and preferentially suppress immune responses mediated by B-lymphocytes. Methotrexate suppresses inflammatory responses through the release of adenosine; they suppress immune responses by inducing the apoptosis of activated T-lymphocytes and inhibit the synthesis of both purines and pyrimidines. Azathioprine metabolites inhibit several enzymes of purine synthesis. Mycophenolic acid inhibits inosine monophosphate dehydrogenase, thereby depleting guanosine nucleotides, inducing the apoptosis of activated T-lymphocytes. A Leflunomide metabolite inhibits dihydroorotate dehydrogenase, thereby suppressing pyrimidine nucleotide synthesis. Cyclosporine and Tacrolimus inhibit the phosphatase activity of Calcineurin, thereby suppressing the production of IL-2 and other cytokines. In addition, these compounds have recently been found to block the JNK and p38 signaling pathways triggered by antigen recognition in T-cells. In contrast, Rapamycin inhibits both kinases required for cell cycling and responses to IL-2; it also induces apoptosis of activated T-lymphocytes.A promising future is the application of biologic immunosuppressive drugs. We review their role and action mechanisms.

Biological agents in rheumatoid arthritis.

Rheumatoid arthritis (RA) is the commonest inflammatory joint disease with considerable morbidity and mortality. Conventional disease-modifying antirheumatic drugs like methotrexate form the cornerstone of therapy. However, they have several limitations in terms of slow onset of action, adverse effects and modest remission and retention rates. Several cytokines are involved in the pathogenesis of RA. Biological agents that specifically inhibit the effects of tumour necrosis factor-a (TNF-a) or Interleukin-1 (IL-1) represent a major advancement in the treatment of RA. By targeting molecules that are directly involved in the pathogenesis of RA, these therapies are proving to be efficacious, highly specific and better tolerated than standard therapies. The use of these agents needs to be monitored carefully for possible side-effects, including the development of infections. Additional anti-cytokine agents for the treatment of RA are under further development.