Neutrophils from ANCA-associated vasculitis patients show an increased capacity to activate the complement system via the alternative pathway after ANCA stimulation.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV), including granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), are autoimmune conditions associated with small vessel inflammation. Earlier studies indicate that complement activation via the alternative pathway plays a major role in the pathogenesis. In this study we have investigated if ANCA-activation of neutrophils from AAV patients leads to activation of the alternative complement pathway. C5a-primed neutrophils (PMN) from 10 AAV patients and 10 healthy controls (HC) were stimulated with PMA or IgG purified from PR3-ANCA positive patients (ANCA IgG). The supernatants were analyzed for release of complement proteins and markers of different granules by ELISA, and release of microparticles (MP) by flow cytometry. The ability of the supernatants to activate the alternative complement pathway was determined by incubation with normal serum and C3bBbP and C5a were measured by ELISA. MP were analyzed by flow cytometry and removed by centrifugation. The supernatants from the AAV patients' neutrophils produced significantly more C3bBbP compared with HCs (p = 0.0001). C3bBbP levels correlated with the number of MP. After removal of MP from the supernatants, alternative pathway activation was significantly lower. This study shows that primed and ANCA-stimulated neutrophils from AAV patients have a greater ability to activate the alternative complement pathway compared to primed neutrophils from healthy controls. This finding emphasizes the role of complement in the pathogenesis of AAV - underlining the therapeutic potential of C5a and other complement blockade.

Patients double-seropositive for ANCA and anti-GBM antibodies have varied renal survival, frequency of relapse, and outcomes compared to single-seropositive patients.

Co-presentation with both ANCA and anti-GBM antibodies is thought to be relatively rare. Current studies of such 'double-positive' cases report small numbers and variable outcomes. To study this further we retrospectively analyzed clinical features and long-term outcomes of a large cohort of 568 contemporary patients with ANCA-associated vasculitis, 41 patients with anti-GBM disease, and 37 double-positive patients with ANCA and anti-GBM disease from four European centers. Double-positive patients shared characteristics of ANCA-associated vasculitis (AAV), such as older age distribution and longer symptom duration before diagnosis, and features of anti-GBM disease, such as severe renal disease and high frequency of lung hemorrhage at presentation. Despite having more evidence of chronic injury on renal biopsy compared to patients with anti-GBM disease, double-positive patients had a greater tendency to recover from being dialysis-dependent after treatment and had intermediate long-term renal survival compared to the single-positive patients. However, overall patient survival was similar in all three groups. Predictors of poor patient survival included advanced age, severe renal failure, and lung hemorrhage at presentation. No single-positive anti-GBM patients experienced disease relapse, whereas approximately half of surviving patients with AAV and double-positive patients had recurrent disease during a median follow-up of 4.8 years. Thus, double-positive patients have a truly hybrid disease phenotype, requiring aggressive early treatment for anti-GBM disease, and careful long-term follow-up and consideration for maintenance immunosuppression for AAV. Since double-positivity appears common, further work is required to define the underlying mechanisms of this association and define optimum treatment strategies.

Thromboprophylaxis and Incidence of Venous Thromboembolism in Patients With Hemophilia A or B Who Underwent High-Risk Orthopedic Surgeries.

Total hip replacement (THR) and total knee arthroplasty (TKA) carry a high risk of postoperative venous thromboembolism (VTE); therefore, anticoagulation prophylaxis is recommended in these patients. Unfortunately, there are no guidelines about VTE prophylaxis in patients with hemophilia who underwent these high-risk surgeries. To determine whether these patients have high risk of VTE, we conducted a retrospective study on patients with hemophilia who underwent elective THR/TKA at our institute from 2004 to 2012. Postoperatively, we collected information on duration and method of factor VIII/IX infusion, VTE-prophylaxis, and complications. There were 23 patients with hemophilia, 18 (78%) with hemophilia A and 5 (22%) with hemophilia B, who underwent high-risk surgeries (39% THR and 61% TKA). The VTE prophylaxis included sequential compression device, 12 (52%), and prophylactic enoxaparin, 1 (4%). Ten (43%) patients did not receive VTE prophylaxis. At 1-year follow-up, we did not find any evidence of clinical VTE in our patients. Better risk stratification is needed to identify patients who would benefit from pharmacological prophylaxis.

Catechol-O-methyltransferase gene polymorphisms are not associated with multisomatoform disorder in a group of German multisomatoform disorder patients and healthy controls.

The etiology of multisomatoform disorder (MSD) is largely unknown, but genetic disposition may be one of several risk factors. As pain is a major component of MSD, and polymorphisms in the catechol-O-methyltransferase (COMT) gene are associated with COMT enzymatic activity and pain sensitivity, we assumed that COMT polymorphisms could be associated with MSD. One hundred and forty-nine patients with MSD and 149 age- and sex-matched healthy controls participated in this study. The inclusion criteria for MSD were in accordance with the structured clinical interview of the diagnostic and statistical manual of mental disorders IV. DNA from MSD patients and controls was genotyped for six single-nucleotide polymorphisms (SNPs) within the COMT locus by polymerase chain reaction and restriction enzyme analysis. The distribution of COMT SNP alleles, genotypes, and haplotypes was compared between patients and controls. None of the investigated SNPs, including the functionally relevant common SNP in codon 158 (Val158Met), showed a statistically significant allelic, genotypic, or haplotypic association with MSD. We conclude that COMT polymorphisms on their own do not seem to play a relevant role as major genetic risk factors for MSD.

Telomere shortening and chromosomal instability in myelodysplastic syndromes.

Telomere shortening and chromosomal instability are believed to play an important role in the development of myeloid neoplasia. So far, published data are only available on the average telomere length in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), but not on the telomere length of individual chromosomes. We used a new technique, telomere/centromere-fluorescence in situ hybridization (T/C-FISH), which combines fluorescence R-banding and FISH using a probe against the telomere repeats to measure the telomere length of each chromosome arm in 78 patients with MDS. In line with the previous results, patients with MDS showed significantly shorter telomeres than those of healthy controls. Telomere lengths did not differ significantly between distinct morphological subtypes of MDS. However, there was a significant difference in telomere length between patients with an isolated monosomy 7 and patients with a normal karyotype (P < 0.05). Notably, patients with an isolated monosomy 7 showed significantly longer telomeres than patients with a normal karyotype in many chromosome arms, among them 7p and 7q. Neo-telomeres were found in two patients with a complex karyotype, in one case at the fusion site of a dic(14;20). Normal and aberrant metaphases of the same patient did not differ in telomere length, thus indicating to telomere shortening as a basic mechanism affecting all hematopoietic cells in patients with MDS. In some MDS subtypes, like MDS with isolated monosomy 7, telomeres may be stabilized and even increase in length because of the activation of telomerase or alternative mechanisms.