Uso de belimumabe em paciente com lúpus eritematoso sistêmico refratário ao tratamento convencional: relato de caso / Use of belimumab in a patient with systemic lupus erythematosus refractory to conventional treatment: case report

O lúpus eritematoso sistêmico (LES) é uma doença de caráter imunomediado, ocasionada por fatores hormonais, ambientais e genéticos. Caracteriza-se pela presença de autoanticorpos reativos para diferentes células e tecidos, apresentando manifestações clínicas diversificadas, períodos de exacerbação e remissão, o que dificulta o tratamento desses pacientes. Este relato de caso destaca o progresso do uso de anticorpo monoclonal humano em uma paciente do gênero feminino, diagnosticada com LES em maio de 2019, aos 30 anos, e, por ser refratária ao tratamento medicamentoso convencional, utilizou o tratamento com anticorpo monoclonal humano belimumabe, com início em setembro de 2019. O belimumabe é um anticorpo monoclonal humano que se liga à proteína estimuladora de linfócito B (BLyS) solúvel, inclusive dos autorreativos, e desta maneira, reduz a diferenciação de linfócitos B em plasmócitos, diminuindo os níveis de IgG sérica e dos anticorpos anti-dsDNA, além de melhorar o quadro clínico dos pacientes. Apesar de ser um medicamento biológico de alto custo, diminui drasticamente os sintomas clínicos do LES, possibilitando a redução do uso do corticoide e os efeitos consequentes de seu uso, além de reestabelecer os parâmetros laboratoriais alterados pela doença, sem alteração de indicadores hepáticos e renais. O LES não tem cura, logo, o objetivo do tratamento é diminuir os sintomas e conter as fases ativas da doença.

Systemic lupus erythematosus is an immune-mediated disease caused by hormonal, environmental and genetic factors. It is characterized by the presence of reactive autoantibodies to different cells and tissues, with diverse clinical manifestations and periods of exacerbation and remission, which complicates treatment. This case report highlights progress with the use of a human monoclonal antibody in a woman diagnosed with systemic lupus erythematosus in May 2019 (at age 30). Since she was refractory to conventional drugs, belimumab treatment was begun in September 2019. Belimumab is a human monoclonal antibody that binds to soluble B lymphocyte-stimulating proteins, including self-reactive ones, and reduces the differentiation of B lymphocytes into plasma cells, decreasing the serum IgG and anti-dsDNA antibody levels, in addition to improving patient clinical status. Despite being a high-cost biological drug, it drastically reduces the clinical symptoms of systemic lupus erythematosus, enabling reduced used of corticosteroids and their effects, in addition to reestablishing laboratory parameters altered by the disease, without changing liver and kidney indicators. Since systemic lupus erythematosus has no cure, the goal of treatment is to reduce symptoms and the active phases of the disease.

Silibinin induces in vitro M2-like phenotype polarization in monocytes from preeclamptic women.

Preeclampsia (PE) is a pregnancy-specific syndrome featuring intense activation of circulating monocytes and an imbalance between pro- and anti-inflammatory cytokines. The present study evaluated the immunomodulatory effect of silibinin (Sb) on the expression of surface markers and the nuclear transcription factor NF-κB signalling pathway of monocytes from preeclamptic women. Monocytes were cultured with or without Sb, and the mean fluorescence intensity of the surface molecules TLR4, CD64, and CD163 as well as the intracellular transcription factors IκB-α and NF-κBp65 was analysed by flow cytometry. The concentration of cytokines in the monocyte culture supernatant was determined by cytometric bead array and ELISA immunoassay. The results showed that the in vitro treatment of monocytes from preeclamptic women with Sb downregulated the endogenous activation of NF-κB and the expression of surface receptors TLR4 and CD64, and reduced the synthesis of the pro-inflammatory cytokines interleukin 1 (IL-1ß), IL-6, IL-8, IL-12p70, IL-23, and tumour necrosis factor alpha (TNF-α) compared with cultures not treated with Sb. The presence of this flavonoid in monocyte cultures increased the expression of CD163 and IκBα and the release of IL-10 and transforming growth factor beta (TGF-ß) in the culture supernatants, polarising these cells from the M1-like profile to the M2-like profile. The anti-inflammatory activity of Sb on the NF-κB activation pathway and induction of cell polarisation to the M2 profile was confirmed by an in vitro assay using monocytes from healthy, non-pregnant women. Treatment of monocytes from preeclamptic women with Sb polarises the cells to the M2-like phenotype, suggesting that this flavonoid has an immunomodulatory effect on the sterile inflammation characteristic of PE.

Increased TLR4 pathway activation and cytokine imbalance led to lipopolysaccharide tolerance in monocytes from preeclamptic women.

Preeclampsia (PE) is a pregnancy syndrome characterized by a systemic inflammatory response, and endogenous activation of monocytes. This study aimed to determine whether the activation of monocytes from preeclamptic women might interfere with the response to lipopolysaccharide (LPS)-in vitro stimulation. Fifty-two preeclamptic women and 32 normotensive (NT) pregnant women were included. Monocytes from peripheral blood were cultured with or without LPS. TLR4 expression was analyzed by flow cytometry, NF-κB activity was determined in nuclear extracts and cytokines production was evaluated by ELISA. Endogenous TLR4 ligands such as Hyaluronan, HMGB1 and Hsp70 were determined in plasma. The endogenous TLR4 expression and activation of NF-κB were statistically higher in monocytes from women with PE compared to NT group. Early-onset PE showed higher TLR4 expression compared to late-onset PE. Plasma levels of Hyaluronan, HMGB1, and Hsp70, as well as endogenous production of inflammatory cytokines, were elevated whilst lower production of IL-10 was observed in the PE group. After culture with LPS, monocytes presented lower NF-κB activation, TNF-α and IL-12 production in PE groups than in the NT group. The study demonstrates endogenous activation of monocytes from preeclamptic women, accompanied by higher expression of TLR4, NF-κB activation and elevated production of pro-inflammatory cytokines. The higher plasma levels of the TLR4 ligands hyaluronan, HMGB1 and hsp70, as well as the high concentration of TNF-α endogenously produced by monocytes, could induce the LPS tolerance phenomenon in these cells. These results suggest that monocytes play an important role in the maternal excessive systemic inflammatory response in PE.