Plasmapheresis in Antineutrophil Cytoplasmic Antibodies‐Associated Systemic Vasculitis

Plasma Exchange Is Highly Effective for Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis Patients With Rapidly Progressive Glomerulonephritis Who Have Advanced to Dialysis Dependence: A Single-Center Case Series

Plasma exchange (PEX) can be an effective treatment in anti-neutrophil cytoplasmic antibody-associated vasculitis with severe renal damage; however, it is still controversial. Among cases of newly diagnosed AAV with rapidly progressive glomerulonephritis at our department from 2008 onward, 11 patients who received PEX (seven cases for severe renal damage [R-PEX] and four cases for lung hemorrhage [L-PEX]) were retrospectively analyzed. All cases of R-PEX were dependent on hemodialysis at the beginning of PEX and all received seven sessions of PEX (50 mL/kg or 1.3 plasma volume per exchange) within 2 weeks. All cases became dialysis-independent within 8 weeks, with 3- and 12-month cumulative renal survival rates of 100% and 80%, respectively. All cases of L-PEX retained their renal function. In rapidly developing, newly dialysis-dependent antibody-associated vasculitis with rapidly progressive glomerulonephritis patients with normal renal function before disease onset, standard PEX can be expected to induce sufficient renal recovery to establish dialysis independence.

Antineutrophil cytoplasmic antibody-associated vasculitis with renal involvement: the evidence for treatment

Antineutrophil cytoplasmic antibody-associated vasculitis is an autoimmune disease involving small to medium blood vessels. It is an uncommon illness, but can have devastating consequences, particularly on kidney function and other vital organs. Exciting progress has been made in the treatment of the disease largely because of international collaboration in randomised clinical trials. Patient survival has improved dramatically with advancements in disease diagnosis and medical treatment. The long-term morbidity from the disease, although improving, remains substantial with up to 10% of survivors requiring dialysis or kidney transplantation. Clinical trials are underway using more specifically targeted immunosuppressants in the hope to improve the long-term patient outcomes. Advancements are also being made in understanding the pathogenesis of the disease and this will further assist disease treatment and outcomes in the future.

Difficult decisions in the intensive care unit: an illustrative case

Difficult clinical decision-making is a common experience in intensive care units. There is often considerable pressure on time and decisions may have to be made in a stressful environment. Patients in the intensive care unit not infrequently present with extreme or rare manifestations of a disease process. Clinical evidence to guide management of such patients may be incomplete, non-existent, or its relevance to the problem at hand may be questionable. In this context, formal decision-making analytical tools are often impractical. Unconscious cognitive biases have been shown to play an important role in medical decision-making, particularly in these settings. While mostly these contribute to doctors making appropriate and timely decisions, occasionally they lead to errors. Despite 30 years of research into models of clinical reasoning, most doctors are unaware of how biases affect their thinking and are unfamiliar with techniques of detecting and neutralising bias in clinical practice. We present the case of a patient with Wegener's granulomatosis, which highlights many of the difficulties outlined above. We review the clinical evidence for our decisions at each stage and explain the rationale for our choices, highlighting the many situations for which high quality evidence was lacking. Examples of cognitive bias are identified and techniques of metacognition (thinking about thinking) that can be useful in limiting the effects of bias on complex decision-making are reviewed. The intensivist's evaluation of management alternatives has an important role in steering medical management towards optimal patient outcomes.

Advances in the therapy of Wegener's granulomatosis

PURPOSE OF REVIEW

In the past, recommendations for the treatment of Wegener's granulomatosis were primarily based on findings reported from open-label clinical trials. Results from several randomized controlled trials in patients with Wegener's granulomatosis and other antineutrophil cytoplasm antibody-associated vasculitides have recently been reported that have a great impact on patient care.

RECENT FINDINGS

In view of the considerable toxicity of cyclophosphamide, strategies to limit exposure to it have recently been evaluated. The replacement of cyclophosphamide by azathioprine after the successful induction of remission has been demonstrated not to increase the rate of relapse compared with continued cyclophosphamide. In patients with early antineutrophil cytoplasm antibody-associated vasculitides without critical organ manifestations low-dose methotrexate can replace cyclophosphamide for induction treatment with similar remission rates. As the early discontinuation of immunosuppressive treatment is associated with unacceptably high relapse rates, however, treatment for the maintenance of remission is mandatory. Besides azathioprine, leflunomide and methotrexate were efficacious in preventing relapses in Wegener's granulomatosis. Data on anti-cytokine therapy in Wegener's granulomatosis are controversial, possibly related to differences in study design. Open-label clinical studies suggest a beneficial effect of infliximab in addition to standard therapy in refractory Wegener's granulomatosis. In contrast, a recent randomized controlled trial showed that etanercept in addition to standard therapy, with the subsequent tapering of standard medications, is not effective for the maintenance of remission.

SUMMARY

Despite recent progress, the prevention of relapses and treatment of refractory cases remain the greatest challenges in the treatment of Wegener's granulomatosis.

Update in the Diagnosis and Management of Pulmonary Vasculitis

The term vasculitis encompasses a number of distinct clinicopathologic disease entities, each of which is characterized pathologically by cellular inflammation and destruction of the blood vessel wall, and clinically by the types and locations of the affected vessels. While multiple classification schemes have been proposed to categorize and simplify the approach to these diseases, ultimately their diagnosis rests on the identification of particular patterns of clinical, radiologic, laboratory, and pathologic features. While lung involvement is most commonly seen with the primary idiopathic, small-vessel or antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides of Wegener granulomatosis, microscopic polyangiitis, and Churg-Strauss syndrome, one should remember that medium-vessel vasculitis (ie, classic polyarteritis nodosa), large-vessel vasculitis (ie, Takayasu arteritis), primary immune complex-mediated vasculitis (ie, Goodpasture syndrome), and secondary vasculitis (ie, systemic lupus erythematosus) can all affect the lung. However, for the purpose of this review, we will focus on the ANCA-associated vasculitides.

Anti-neutrophil cytoplasm antibody IgG subclasses in Wegener's granulomatosis: a possible pathogenic role for the IgG4 subclass

A characteristic feature of Wegener's granulomatosis is the presence of antineutrophil cytoplasm antibodies (ANCA) to proteinase 3 (PR3). In vitro, ANCA activate neutrophils by co-ligating PR3 and FcgammaRIIa/IIIb receptors. ANCA are predominantly of the IgG isotype, and IgG1, IgG3 and IgG4 subclasses are particularly represented. To address the pathogenic role of individual ANCA-IgG subclass antibodies, patients' sera were screened using indirect immunofluorescence, enzyme-linked immunosorbent assay (ELISA) and subclass PR3-ELISA to identify patients with high titres of PR3-ANCA within the IgG1, IgG3 or IgG4 subclasses. Unfractionated ANCA-IgG and subclass fractions were isolated by affinity chromatography and compared for their capacities to stimulate superoxide production by primed human neutrophils. Donor neutrophils were analysed for constitutive and induced FcgammaRI expression by flow cytometry. The IgG1, IgG3 and IgG4 subclass fractions, isolated from three different ANCA sera, each stimulated superoxide production from neutrophils derived from multiple donors. Subsequently, IgG4 subclass fractions isolated from a further four ANCA positive sera demonstrated varying abilities to stimulate release of superoxide; unrelated to PR3-ANCA titre, neutrophil donor, or neutrophil FcgammaRI expression. The stimulation of superoxide release by IgG1- and IgG3-ANCA subclass fractions is consistent with the proposed mechanism of co-ligation of PR3 antigen and FcgammaRIIa/IIIb receptors. However, the demonstration of similar activity for the IgG4-ANCA subclass fractions isolated from some sera was unexpected. This activity was independent of neutrophil donor and expression of FcgammaRI, suggesting it was capable of activating neutrophils via constitutively expressed FcgammaRIIa/IIIb or co-ligation of other, unidentified, cell surface molecules.