Current Understanding and Unknown Aspects of the Treatment of Granulomatosis with Polyangiitis (Wegener's Granulomatosis): Opportunities for Future Studies.

Granulomatosis with polyangiitis (GPA) is a rare and systemic autoimmune disease, causing necrotizing vasculitis of small arteries and veins. The majority of diagnosed patients with GPA have circulating anti-neutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3). Here, we have reviewed the last findings and uncertainties regarding the treatment of GPA. Between the available treatments, in addition to corticosteroids, cyclophosphamide (CYP) is effective for remission-induction, while it is associated with some serious side effects, such as infertility and increased risk of malignancies. On the other side, rituximab (RTX) seems a safer alternative option and as effective as CYP. It could be used as both remission-induction and maintenance therapy in GPA patients, especially in women of childbearing age. Pregnant patients, who must not be exposed to the CYP and RTX could be well-managed with intravenous immunoglobulin (IVIg). Co-trimoxazole, which is widely used to treat certain bacterial infections or as prophylaxis in immunosuppressed patients, could be effective in preventing disease relapse. In the meantime, 15- deoxyspergualin, plasma exchange are other therapeutic options with a low level of evidence. Regarding potential treatments, ofatumumab, ocrelizumab, belimumab, atacicept, tabalumab, abatacept (CTLA4-Ig), and Janus kinase inhibitors seem to be effective. Renal involvement, older age, the presence of baseline organ damage, delayed-diagnosis of disease, rising in creatinine level, and higher neutrophil/lymphocyte ratio is associated with poor outcomes. Optimum doses of medications, prediction of treatment response and disease relapse, explaining lack of response in some patients, treating children with GPA, and management of GPA during the pregnancy are controversial issues, which need further studies.

Treatment of renal ANCA-associated vasculitides.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a group of small vessel vasculitides which commonly affect the kidneys, manifesting as rapidly progressive glomerulonephritis. In this review, we present different treatment methods (e.g. cyclophosphamide, rituximab, plasma exchange) used for remission induction and maintenance in renal AAV. We also discuss treatment options in relapsing and refractory disease and for patients with end-stage renal disease due to AAV. In addition, we enumerate the various risk factors associated with relapsing and refractory disease, quality of life impairment and decreased renal and patient survival in AAV. Finally we present information on new, potentially applicable agents which can further help modify the disease course, thereby leading to increased patient survival.

Manifestaciones cutáneas y mucosas asociadas al consumo de cocaína / Cutaneous and mucosal manifestations associated with cocaine use

Las complicaciones secundarias a la cocaína constituyen un problema de salud pública. La manifestación cutánea característica es la vasculitis leucocitoclástica y/o la vasculopatía trombótica habitualmente poco agresiva que afecta principalmente a los pabellones auriculares. No suele presentar afectación sistémica intensa, pero puede acompañarse de múltiples manifestaciones cutáneas, mucosas y sistémicas. Otros hallazgos asociados como las artralgias, la neutropenia o la agranulocitosis, los anticuerpos antinucleares positivos a títulos bajos, y la positividad para anticuerpos antifosfolipídicos y anticuerpos anticitoplasma de neutrófilos frente a múltiples antígenos ayudan al diagnóstico. Esta entidad requiere un diagnóstico precoz, siendo fundamental la sospecha clínica, realizar una adecuada anamnesis, una exploración física completa y un diagnóstico diferencial amplio. El curso suele ser autolimitado. En la mayoría de los casos el único tratamiento necesario es la interrupción del consumo de cocaína asociado a un tratamiento sintomático, sin beneficio demostrado de los corticoides sistémicos (AU)

Complications due to cocaine are a public health problem. The typical cutaneous disease is leukocytoclastic vasculitis and/or thrombotic vasculopathy affecting mainly the ears. No intense systemic involvement is usually present, but there may be several cutaneous, mucosal and systemic manifestations. Other findings associated as arthralgia, neutropaenia or agranulocytosis, low titer positive antinuclear antibodies, antiphospholipid antibody positivity and neutrophil cytoplasmic antibodies against multiple antigens help the diagnosis. This disease requires a clinical suspicion with a clinical history, a complete physical examination and a broad differential diagnosis for an early and correct diagnosis. The course is usually self-limited. In most cases the only treatment is to discontinue the use of cocaine associated with symptomatic treatment, no proven benefit of systemic corticosteroids (AU)

Nanocrystal quantum dot-conjugated anti-myeloperoxidase antibody as the detector of activated neutrophils.

Fluorescent nanocrystal quantum dots (QDs) have been applied to a wide range of biological studies by taking advantage of their fluorescence properties. Here we show that QDs conjugated with antibody against neutrophil peroxidase, myeloperoxidase (MPO). We designed a novel method to conjugate QDs to antibody without losing any antibody function including their antigen recognizing and Fc-receptor binding activities. When we applied anti-MPO antibody (Ab) with conventional organic probes in the case of immunostaining of living cells, the antibodies lost their fluorescence because of MPO enzymic activity to produce reactive oxygen species. Our QD-conjugated anti-MPO (alpha-MPO-QDs) can detect MPO on the surface of activated neutrophils. In addition, anti-MPO-QDs did not react to the inactivated neutrophils. In conclusion, we demonstrated that antibody visualized the expression of MPO on the neutrophil surface after stimulation with proinflammatory cytokines. Taken together, these techniques have the possibility that QDs can reveal the activation of neutrophils by immunostaining and flow cytometric analysis as a powerful tool for diagnosis of the neutrophil activation in vitro.

Neutrophil depletion inhibits experimental abdominal aortic aneurysm formation.

BACKGROUND: Neutrophils may be an important source of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), two matrix-degrading enzymes thought to be critical in the formation of an abdominal aortic aneurysm (AAA). The purpose of this investigation was to test the hypothesis that neutrophil depletion would limit experimental AAA formation by altering one or both of these enzymes. METHODS AND RESULTS: Control, rabbit serum-treated (RS; n=27) or anti-neutrophil-antibody-treated (anti-PMN; n=25) C57BL/6 mice underwent aortic elastase perfusion to induce experimental aneurysms. Anti-PMN-treated mice became neutropenic (mean, 349 cells/microL), experiencing an 84% decrease in the circulating absolute neutrophil count (P<0.001) before elastase perfusion. Fourteen days after elastase perfusion, control mice exhibited a mean aortic diameter (AD) increase of 104+/-14% (P<0.0001), and 67% developed AAAs, whereas anti-PMN-treated mice exhibited a mean AD increase of 42+/-33%, with 8% developing AAAs. The control group also had increased tissue neutrophils (20.3 versus 8.6 cells per 5 high-powered fields [HPFs]; P=0.02) and macrophages (6.1 versus 2.1 cells per 5 HPFs, P=0.005) as compared with anti-PMN-treated mice. There were no differences in monocyte chemotactic protein-1 or macrophage inflammatory protein-1alpha chemokine levels between groups by enzyme-linked immunosorbent assay. Neutrophil collagenase (MMP-8) expression was detected only in the 14-day control mice, with increased MMP-8 protein levels by Western blotting (P=0.017), and MMP-8-positive neutrophils were seen almost exclusively in this group. Conversely, there were no statistical differences in MMP-2 or MMP-9 mRNA expression, protein levels, enzyme activity, or immunostaining patterns between groups. When C57BL/6 wild-type (n=15) and MMP-8-deficient mice (n=17) were subjected to elastase perfusion, however, ADs at 14 days were no different in size (134+/-7.9% versus 154+/-9.9%; P=0.603), which suggests that MMP-8 serves only as a marker for the presence of neutrophils and is not critical for AAA formation. CONCLUSIONS: Circulating neutrophils are an important initial component of experimental AAA formation. Neutrophil depletion inhibits AAA development through a non-MMP-2/9-mediated mechanism associated with attenuated inflammatory cell recruitment.