Resurgence of Shoshin beriberi during the COVID-19 pandemic.

This report describes two patients who presented with severe type B lactic acidosis and shock, initially thought to be due to bowel ischaemia/myocardial infarction and pulmonary sepsis, respectively. This led to a delay in the diagnosis of thiamine deficiency. In both cases there was a dramatic response to intravenous thiamine, confirming the diagnosis of Shoshin beriberi. Both patients admitted to drinking home-brewed alcohol during the time of COVID-19 restrictions on alcohol consumption. These cases highlight the need for early diagnosis and immediate empirical treatment with intravenous thiamine in patients presenting with unexplained severe metabolic acidosis and circulatory shock.

Plasmapheresis in antineutrophil cytoplasmic antibody-associated systemic vasculitis.

Small vessel vasculitis syndromes associated with antineutrophil cytoplasmic antibodies frequently cause a necrotizing and crescentic glomerulonephritis with the potential to progress rapidly to permanent renal failure. These conditions are conventionally treated with immunosuppressive drugs, but the possibility that humoral factors are important in their pathogenesis has led to the evaluation of plasmapheresis as an adjunctive therapy. Both controlled and uncontrolled studies have suggested that the routine addition of plasmapheresis is unnecessary. However, when renal function is impaired to the point that dialysis is required, the addition of plasma exchange increases the chance of renal recovery. The superiority of this approach over pulses of methylprednisolone remains to be confirmed.

Outcome of renal replacement therapy in antineutrophil cytoplasmic antibody-associated systemic vasculitis.

Antineutrophil cytoplasmic antibody-associated systemic vasculitis (AASV) frequently leads to end-stage renal disease (ESRD). Potentially fatal disease activity can continue after the onset of ESRD in both dialysis and transplant patients, despite the immunosuppressive effects of uremia and rejection prophylaxis, leading to concerns that such patients have greater morbidity and mortality. To assess the outcome of AASV patients receiving renal replacement therapy, a retrospective analysis of 59 patients from our unit who received chronic dialysis, renal transplantation, or both, was performed. The survival of AASV patients with ESRD was comparable to national registry controls, as were both graft and patient survival after renal transplantation. Ther is no evidence that standard immunosuppressive protocols should be altered for AASV patients receiving renal transplants. The rate of relapse of vasculitis for patients on chronic dialysis and after transplantation was 0.09 and 0.02 per patient per year, respectively. These rates are lower than those of other series and support the contention that continued immunosuppression after ESRD, as practiced in our unit, is warranted. Relapses usually responded to cyclophosphamide and high-dose prednisolone treatment. Significantly, vasculitic flare-ups in dialysis patients were sometimes initially misdiagnosed as dialysis complications, leading to fatal delays in effective treatment. Follow-up by physicians experienced in the diagnosis and treatment of vasculitis activity should continue in these patients.

Diagnostic value of standardized assays for anti-neutrophil cytoplasmic antibodies in idiopathic systemic vasculitis. EC/BCR Project for ANCA Assay Standardization.

Anti-neutrophil cytoplasmic antibodies (ANCA) are widely used as diagnostic markers for Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), Churg-Strauss syndrome (CSS) and idiopathic rapidly progressive glomerulonephritis (iRPGN). The objective of this study was to evaluate the diagnostic value of ANCA measurement by the indirect immunofluorescence (IIF) test, and by anti-PR3 and anti-MPO ELISA performed in different locations, in patients with idiopathic small vessel vasculitis. Fourteen centers participated in a standardization study of ANCA assays, and entered a total number of 169 newly diagnosed and 189 historical patients with idiopathic systemic vasculitis or iRPGN. Patients were classified according to a pre-defined diagnostic classification system. Results were compared with those of 184 disease controls and 740 healthy controls. The IIF test was performed according to standard methodology; ELISAs had been standardized among the participants in a previous phase of the study. The sensitivities of assays in patients were as follows. The sensitivity in WG was: cANCA 64%, pANCA 21%, anti-PR3 66%, anti-MPO 24%. In MPA the sensitivity was: cANCA 23%, pANCA 58%, anti-PR3 26%, anti-MPO 58%. Sensitivity in iRPGN was: cANCA 36%, pANCA 45%, anti-PR3 50%, anti-MPO 64%. The specificity of assays (related to disease controls) was: cANCA 95%, pANCA 81%, anti-PR3 87%, anti-MPO 91%. When the results of the IIF test were combined with those of the ELISAs (cANCA/anti-PR3 positive, pANCA/anti-MPO positive), the diagnostic specificity increased to 99%. The sensitivity of the combination of cANCA + anti-PR3 or pANCA + anti-MPO for WG, MPA or iRPGN was 73%, 67% and 82%, respectively. From this study we conclude that the value of the IIF test for ANCA detection can be greatly increased by the addition of a well standardized antigen-specific ELISA. In a significant number of patients with idiopathic small vessel vasculitis, however, the ANCA test results (either in IIF or ELISA) are negative.

Relationship between granulocyte activation, pulmonary granulocyte kinetics and alveolar permeability in extrapulmonary inflammatory disease.

1. The aim of the study was to examine the relationship between granulocyte activation, pulmonary intravascular granulocyte transit, pulmonary extravascular granulocyte migration and lung injury in patients with systemic conditions (bone marrow transplant recipients, inflammatory bowel disease and systemic vasculitis) in which abnormalities of pulmonary granulocyte traffic have previously been reported. 2. A double 111In-99mTc granulocyte labelling technique was used for quantification of granulocyte kinetics in 23 patients, of whom five were control patients. The pulmonary vascular granulocyte pool was measured from dynamic data centred on the 99mTc signal and expressed as a percentage of the total blood granulocyte pool. Granulocyte migration was quantified on 24 h images using the 111In signal. Granulocyte activation was measured as the percentage of cells showing a change in shape. The clearance rate of an inhaled aerosol of 99mTc-diethylenetriaminepenta-acetic acid (DTPA) was used as a marker of lung injury. 3. Pulmonary granulocyte pool, migration, activation and aerosol clearance, although highly variable in the patient groups, were, in general, elevated compared with the controls. 4. Granulocyte activation correlated with pulmonary granulocyte pool (Rs = 0.72, n = 22, P < 0.01), while the t1/2 of DTPA clearance correlated with migration (Rs = -0.84, n = 17, P < 0.01). Fifteen patients had an expanded pulmonary granulocyte pool, of whom six with no evidence of migration, had a normal DTPA clearance, while nine, who had an abnormal migration signal, had an accelerated DTPA clearance. The pulmonary granulocyte pool in these nine was significantly higher than in the six without a migration signal. 5. Activation of granulocytes results in delayed transit through the lung vasculature. With increasing margination, granulocytes migrate into the lung interstitium and injure the lung. An increased intravascular pool does not by itself lead to lung injury.

Classification, pathogenesis, and treatment of systemic vasculitis.

Patients with systemic vasculitis (SV), especially Wegener's granulomatosis and microscopic polyangiitis, regularly present with renal involvement. Although considered a rare disease, either the incidence of SV is increasing or it is being increasingly recognized. Accurate classification systems are required to allow comparison of data from different groups investigating and treating these patients. Systemic vasculitis is known to be an autoimmune disease, but the mechanisms of pathogenesis have not been established, despite many studies on this topic in recent years. Most of this work has been done in vitro, although development of animal models is underway. Patient and renal survival have improved with aggressive immunosuppressive treatment, but morbidity is high and controversies remain in establishing the most effective regimens with minimum adverse effects. In this review we discuss the classification of SV, review the current knowledge of pathogenic mechanisms, and consider the relative merits of different treatment protocols.

Development and standardization of solid phase assays for the detection of anti-neutrophil cytoplasmic antibodies (ANCA). A report on the second phase of an international cooperative study on the standardization of ANCA assays.

Anti-neutrophil cytoplasmic antibodies (ANCA) are diagnostic markers for systemic vasculitis. They are classically detected by an indirect immunofluorescence test using normal donor neutrophils as substrate. This assay lacks antigenic specificity and is not quantitative. The 'EC/BCR Project for ANCA Assay Standardization' is an international collaboration study with the aim to develop and standardize solid phase assays for ANCA detection. In this part of the study the isolation and characterization of proteinase-3 and myeloperoxidase, the two main target molecules for ANCA, and the development and standardization of ELISAs with these antigens are described. Six laboratories successfully isolated purified proteinase-3 preparations that could be used. Three of these preparations, together with one myeloperoxidase preparation, were subsequently used for ANCA testing by ELISA. The ELISA technique was standardized in two rounds of testing in the 14 participating laboratories. The coefficient of variation of these new assays decreased from values of approx. 50% in the first round to approx. 20% in the second round. We conclude that purified proteinase-3 and myeloperoxidase can be used in standardized ELISAs for ANCA detection. Whether such procedures offer advantages over the IIF test will be determined in a prospective clinical study.

C-antineutrophil cytoplasmic antibody positivity in vasculitis patients is associated with the Z allele of alpha-1-antitrypsin, and P-antineutrophil cytoplasmic antibody positivity with the S allele.

BACKGROUND: Antineutrophil cytoplasmic antibodies (ANCA) in vasculitis have either cANCA or pANCA patterns as defined by immunofluorescence. The target autoantigen of cANCA is usually proteinase 3 (PR3), whereas that of pANCA is usually myeloperoxidase (MPO). Alpha-1-antitrypsin (alpha 1AT) is the major physiological inhibitor of PR3, while MPO is an inhibitor of alpha 1AT. METHODS: To determine whether there was an association between ANCA positive vasculitis, ANCA pattern, and alpha 1AT deficiency alleles, we studied alpha 1AT phenotypes of 99 cANCA and 99 pANCA positive vasculitis patients by isoelectric focusing and immunoblotting, and compared them with 2310 controls from the same geographical area. RESULTS: C-ANCA patients showed an increased frequency of the Z allele (0.055 versus 0.018 in controls), conferring a relative risk of 3. They showed no increase in frequency of the S allele. P-ANCA patients showed an increased frequency of the S allele (0.091 versus 0.046 in controls) conferring a relative risk of 2. The frequency of the Z allele also appeared to be increased (0.030 versus 0.018 in controls), but this was not statistically significant. CONCLUSIONS: These findings demonstrate an association between ANCA-positive vasculitis and deficiency phenotypes of alpha 1AT, and suggest a role for alpha 1AT in the development of systemic vasculitis.

Relationship between disease activity and anti-neutrophil cytoplasmic antibody concentration in long-term management of systemic vasculitis.

Autoantibodies directed against neutrophil cytoplasmic antigens (ANCA) are valuable in the diagnosis of primary systemic vasculitis, and immunofluorescence studies suggest that changes in ANCA concentration reflect changes in disease activity. We used enzyme-linked immunosorbent assays to examine retrospectively the relationship between ANCA concentration and disease activity in 56 patients with systemic vasculitis. We included patients with Wegener's granulomatosis, microscopic polyangiitis, idiopathic rapidly progressive glomerulonephritis, and Churg-Strauss syndrome, and examined separately the initial treatment period (mean length of follow-up, 26 months) and long-term management (mean length of follow-up, 59 months). Levels of ANCA decreased during induction therapy with prednisolone and cyclophosphamide, with or without plasma exchange. During follow-up, 27 relapses were documented in 20 patients (10 with Wegener's granulomatosis, nine with microscopic polyangiitis, and one with Churg-Strauss syndrome), occurring between 4 and 183 months (mean, 62 months) after initial presentation. Patients in whom ANCA were detectable 1 year or more after treatment were at particular risk of clinical relapse. Proteinase 3-directed ANCA appeared to be associated with a higher rate of relapse (44% of patients relapsed) than myeloperoxidase-directed ANCA (13% of patients relapsed). Twenty-four of the 27 relapses occurred in the presence of detectable ANCA; in 21 of these, ANCA concentration was high or rising. The temporal relationship between changes in ANCA concentration and clinical relapse varied considerably between patients; in seven patients, ANCA remained at high levels for many months (range, 14 to 67 months) before eventual relapse. One patient showed high concentrations of ANCA over a period of 11 years without relapse. In five patients, increases in the ANCA level were not temporally associated with relapse (although four of these patients relapsed on other occasions.) We conclude that monitoring ANCA by enzyme-linked immunosorbent assays is of value in the long-term management of patients with Wegener's granulomatosis, microscopic polyangiitis, idiopathic rapidly progressive glomerulonephritis, and Churg-Strauss syndrome. Increases in ANCA and persistently high levels point to the risk of relapse and indicate the need for frequent clinical review and continuing maintenance immunosuppression. However, our results suggest that ANCA assays should always be used in conjunction with other indices of disease activity and should not be the sole basis for changing therapy.

Use of proteinase 3 purified by reverse phase HPLC to detect autoantibodies in systemic vasculitis.

The vasculitis autoantigen proteinase 3 was purified from neutrophil primary granules using reverse phase high performance liquid chromatography. It was shown to be free of important contaminants, was enzymatically active and was antigenic to sera containing antineutrophil cytoplasmic antibodies with a cytoplasmic pattern (C-ANCA) by indirect immunofluorescence. Development of an enzyme-linked immunosorbent assay showed that this preparation could be used to detect autoantibodies in Wegener's granulomatosis and microscopic polyangiitis. Assays based on reverse phase HPLC-purified proteinase 3 will be valuable in diagnosis and monitoring of treatment, and should increase our understanding of the autoimmune response in primary systemic vasculitis.

ANCA and predicting relapse in systemic vasculitis.

We studied 60 patients with ANCA-positive systemic vasculitis (SV) to assess the prognostic significance of clinical and serological features at presentation, and the value of sequential monitoring of ANCA, C-reactive protein (CRP) and ESR levels as predictors of disease relapse. Patients were recruited at the time of diagnosis, treated with a standard protocol, and assessed monthly for one year. Clinical remission was achieved in 56/60 (93%), and ANCA became undetectable in 50/60 (83%) after treatment. During the one year follow-up period, disease relapses were seen in 23 (38%) patients. No specific associations were observed between initial disease presentation, initial ANCA level or ANCA antigenic specificity and relapse. However, 13/23 (57%) of relapses were preceded by a rise in ANCA a mean of 7.8 weeks earlier, while at the time of relapse 19/23 (83%) were ANCA-positive. Rises in CRP and ESR occurred in 23/60 (38%) and 14/43 (33%), respectively, but were less closely associated with relapse than ANCA. A sustained rise in ANCA was seen in six patients without relapse while clinical relapse occurred with a negative ANCA in four. Sequential ANCA monitoring at monthly intervals during disease remission is of value, at least during the first year, in the prediction and diagnosis of relapse in SV, and is superior to measurement of CRP or ESR.

Anti-neutrophil cytoplasm antibodies can recognize vascular endothelial cell-bound anti-neutrophil cytoplasm antibody-associated autoantigens.

Anti-neutrophil cytoplasm antibodies (ANCA) are strongly associated with the development of systemic vasculitis. Myeloperoxidase and proteinase-3 have been identified as targets for P-ANCA and C-ANCA, respectively. Both enzymes are released from neutrophil azurophil granules following neutrophil activation and both are highly cationic. Purified myeloperoxidase is demonstrated to bind non-convalently to endothelial cell membranes, to retain its enzymic function following binding, and to retain its antigenicity for P-ANCA. Endothelial cell-bound myeloperoxidase enhances complement-dependent cytotoxicity of some P-ANCA sere that also contain anti-endothelial cell antibodies. Studies using purified proteinase-3 show that it also can bind to endothelial cells and be recognized by C-ANCA. The interactions of myeloperoxidase and proteinase-3 with endothelial cells and ANCA may thus contribute to the development of vascular injury in patients with systemic vasculitis.

Renal transplantation following immunoadsorption in highly sensitized recipients.

Five highly sensitized patients, with panel reactivity greater than 80% for 1.75-5 years, were treated by extracorporeal staphylococcal protein-A immunoadsorption, prednisolone, and cyclophosphamide. The five patients underwent treatment of 18-40 (mean 31) liters of plasma, respectively in 4-7 (mean 5.6) sessions. This reduced the titer of cytotoxic antibodies to sensitizing antigens to < 1/8 in all cases and abolished reactivity to crossreacting antigens. Two patients required retreatment following resynthesis of cytotoxic antibodies. All five patients have been transplanted, and four of these now have stable serum creatinines of 168 mumol/L at 34 months, 208 mumol/L at 29 months, 96 mumol/L at 5 months, and 125 mumol/L at 3 months posttransplantation. One patient had primary graft dysfunction due to acute tubular necrosis; the kidney was removed after eight weeks and showed cortical necrosis without evidence of acute rejection.

The value of indirect immunofluorescence and solid phase techniques for ANCA detection. A report on the first phase of an international cooperative study on the standardization of ANCA assays. EEC/BCR Group for ANCA Assay Standardization.

This study describes the results of phase I of an international effort to develop and standardize assays for the detection of anti-neutrophil cytoplasmic antibodies (ANCA). 12 sera, four of which were selected for their potential to cause problems in the detection of various ANCA specificities, were analyzed in the standard indirect immunofluorescence (IIF) test and in ELISAs for ANCA routinely performed in the seven participating laboratories. The IIF methodology differed with respect to the dilution of the serum being screened and the concentration of the conjugate used. Results from sera with high ANCA titers were similar, although the quantitative values could not be compared. In sera containing rheumatoid factor and anti-nuclear antibodies (ANA), ANCA-unrelated staining patterns were observed. Six antigen preparations were used in ELISA for the detection of cANCA. In ELISA with purified proteinase-3 all three cANCA sera were positive, but not anti-myeloperoxidase (MPO) or anti-lactoferrin (LF) positive sera. The other assays were less sensitive or gave inconsistent results. Various preparations of purified MPO and LF used in ELISA were readily recognized by anti-MPO and anti-LF positive sera. From this study it can be concluded that the IIF test, although performed with different methods, shows comparable results using strongly positive sera. In general solid phase assays for cANCA detection are not well standardized and need improvement although the purified proteinase-3 ELISA is possibly an exception. MPO and LF can be used in ELISA procedures for the detection of pANCA-related antibodies.