Erdheim-Chester disease and knee pain in a dialysis patient

Erdheim–Chester disease is a rare inflammatory condition characterized by a non-Langerhans histiocytic infiltration, involving the skeleton, nervous system, viscera, retroperitoneum and elsewhere. The aetiology is unknown. Positron emission tomography shows areas of involvement. We managed a dialysis patient with knee pain; a bone marrow specimen showed typical CD68 positive, but CD1a negative cells. We initiated interferon-α therapy although other options remain open. In our patient, the simultaneous presence of secondary hyperparathyroidism with tumorous calcifications provided an interesting additional differential diagnostic possibility regarding skeletal pain

Iatrogene Elektrolytstoerungen [Iatrogenic Electrolyte Disorders]

The maintenance of water and electrolyte homeostasis is of enormous importance for the functioning of cells and tissues. A number of therapeutic procedures intentionally or unintentionally influence important regulatory mechanisms of these interdependent balanced systems. Excessive salt intake doesn't only expand the extracellular volume; it can also cause a considerable increase in tonicity. Owing to its insulin-dependent duality of action, glucose can represent an effective or an ineffective osmolyte. This fact has to be considered in patients with diabetic ketoacidosis. Diuretics reduce the volume expansion via renal excretion of sodium (and water); however, in addition to hypokalemia, diuretics can also cause severe alkalosis. Nowadays, hemodialysis is a routine procedure-but even routine procedures can deliver undesirable surprises. Can dialysis cause an increase in calcium levels, or does the procedure remove therapeutically administered radioactive iodine? The current article presents a series of cases we have come across in recent years. These case reports illustrate common, but also rare iatrogenic situations. The discussion of these cases is aimed at raising awareness of the issues involved in a pathophysiological approach to clinical problems

Gene silencing and a novel monoallelic expression pattern in distinct CD177 neutrophil subsets

CD177 presents antigens in allo- and autoimmune diseases on the neutrophil surface. Individuals can be either CD177-deficient or harbor distinct CD177(neg) and CD177(pos) neutrophil subsets. We studied mechanisms controlling subset-restricted CD177 expression in bimodal individuals. CD177(pos), but not CD177(neg) neutrophils, produced CD177 protein and mRNA. Haplotype analysis indicated a unique monoallelic CD177 expression pattern, where the offspring stably transcribed either the maternal or paternal allele. Hematopoietic stem cells expressed both CD177 alleles and silenced one copy during neutrophil differentiation. ChIP and reporter assays in HeLa cells with monoallelic CD177 expression showed that methylation reduced reporter activity, whereas demethylation caused biallelic CD177 expression. HeLa cell transfection with c-Jun and c-Fos increased CD177 mRNA. Importantly, CD177(pos) human neutrophils, but not CD177(neg) neutrophils, showed a euchromatic CD177 promoter, unmethylated CpGs, and c-Jun and c-Fos binding. We describe epigenetic mechanisms explaining the two distinct CD177 neutrophil subsets and a novel monoallelic CD177 expression pattern that does not follow classical random monoallelic expression or imprinting

β2 integrin-mediated cell-cell contact transfers active myeloperoxidase from neutrophils to endothelial cells

Atherosclerosis and vasculitis both feature inflammation mediated by neutrophil-endothelial-cell (EC) contact. Neutrophil myeloperoxidase (MPO) can disrupt normal EC function, although the mechanism(s) by which MPO is transferred to EC are unknown. We tested the hypothesis that close, beta2-integrin-dependent neutrophil-EC contact mediates MPO transfer from neutrophils to EC. We used sensitive MPO assays and flow cytometry to detect MPO in EC and demonstrate that EC acquired MPO when contacted by neutrophils directly but not when EC and neutrophils were separated in transwells. The transfer was dependent on neutrophil number, exposure time, and incubation temperature. Transfer occurred in several EC types, increased with endotoxin, was not accompanied by MPO release into the medium and was not abrogated by inhibiting degranulation to secretagogues. Confocal microscopy showed MPO internalization by EC with cytoplasmic and nuclear staining. Neutrophils and EC formed intimate contact sites demonstrated by electron microscopy. Blocking CD11b or CD18 beta2-integrin chains, or using neutrophils from CD11b gene-deleted mice, reduced MPO transfer. EC-acquired MPO was enzymatically active, as demonstrated by its ability to oxidize the fluorescent probe aminophenyl fluorescein in the presence of a hydrogen peroxide source. The data suggest an alternative to EC uptake of soluble MPO, namely the cell contact-dependent, {beta}2-integrin-mediated transfer from neutrophils. The findings could be of therapeutic relevance in atherosclerosis and vasculitis

The repertory of bone marrow progenitor cells associated with lymphogenic metastasis in patients with invasive carcinoma of no special type

The high mortality of patients with breast cancer is determined by metastatic disease. It is thought that the metastatic disease development associated with the repertory of bone marrow progenitor cells in breast cancer patients. In our study the correlation between the bone marrow progenitor cells presences in the tumor and blood of patients and the lymphogenic metastasis development was studied. The main clinical and pathological parameters of 24 patients with invasive breast carcinoma of non-specific type were analyzed. Endothelial progenitor cells, mesenchymal stem cells, macrophage precursors, hematopoietic progenitor cells were detected with specific antibodies against CD34, CD133, CD90, VEGFR1, CD11b, CD45, CD202 in the cell-rich fluid from frozen tumor. The amount of MCP-1 in the patients blood serum was assessed by enzymelinked immunosorbent assay (ELISA), at a wavelength of 450 nm. The cytokines concentration was calculated from the calibration plot. The program package Statistica 10.0. was used for statistical data processing. The high risk of lymphogenic metastasis in patients who didn't complete a neoadjuvant chemotherapy course was associated with the number of HPC, EPC and MSC in tumor and MCP-1 in blood

Hypoxia-inducible factors not only regulate but also are myeloid-cell treatment targets

Hypoxia describes limited oxygen availability at the cellular level. Myeloid cells are exposed to hypoxia at various bodily sites and even contribute to hypoxia by consuming large amounts of oxygen during respiratory burst. Hypoxia-inducible factors (HIFs) are ubiquitously expressed heterodimeric transcription factors, composed of an oxygen-dependent α and a constitutive β subunit. The stability of HIF-1α and HIF-2α is regulated by oxygen-sensing prolyl-hydroxylases (PHD). HIF-1α and HIF-2α modify the innate immune response and are context dependent. We provide a historic perspective of HIF discovery, discuss the molecular components of the HIF pathway, and how HIF-dependent mechanisms modify myeloid cell functions. HIFs enable myeloid-cell adaptation to hypoxia by up-regulating anaerobic glycolysis. In addition to effects on metabolism, HIFs control chemotaxis, phagocytosis, degranulation, oxidative burst, and apoptosis. HIF-1α enables efficient infection defense by myeloid cells. HIF-2α delays inflammation resolution and decreases antitumor effects by promoting tumor-associated myeloid-cell hibernation. PHDs not only control HIF degradation, but also regulate the crosstalk between innate and adaptive immune cells thereby suppressing autoimmunity. HIF-modifying pharmacologic compounds are entering clinical practice. Current indications include renal anemia and certain cancers. Beneficial and adverse effects on myeloid cells should be considered and could possibly lead to drug repurposing for inflammatory disorders

Competitively disrupting the neutrophil-specific receptor-autoantigen CD177:proteinase 3 membrane complex reduces anti-PR3 antibody-induced neutrophil activation

CD177 is a neutrophil-specific receptor presenting the proteinase 3 (PR3) autoantigen on the neutrophil surface. CD177 expression is restricted to a neutrophil subset, resulting in CD177(pos)/mPR3(high) and CD177(neg)/mPR3(low) populations. The CD177(pos)/mPR3(high) subset has implications for anti-neutrophil cytoplasmic autoantibody (ANCA)-associated autoimmune vasculitis (AAV), wherein patients harbor PR3-specific ANCAs that activate neutrophils for degranulation. Here we generated high-affinity anti-CD177 monoclonal antibodies, some of which interfered with PR3 binding to CD177 (PR3 "blockers") as determined by surface plasmon resonance spectroscopy, and used them to test the effect of competing PR3 from the surface of CD177(pos) neutrophils. Because intact anti-CD177 antibodies also caused neutrophil activation, we prepared non-activating Fab fragments of a PR3 blocker and non-blocker that bound specifically to CD177(pos) neutrophils. We observed that Fab blocker clone 40, but not non-blocker clone 80, dose-dependently reduced anti-PR3 antibody binding to CD177(pos) neutrophils. Importantly, preincubation with clone 40 significantly reduced respiratory burst in primed neutrophils challenged with either monoclonal antibodies to PR3 or PR3-ANCA IgG from AAV patients. After separating the two CD177/mPR3 neutrophil subsets from individual donors by magnetic sorting, we found that PR3-ANCAs provoked significantly more superoxide production in CD177(pos)/mPR3(high) than in CD177(neg)/mPR3(low) neutrophils, and that anti-CD177 Fab clone 40 reduced the superoxide production of CD177(pos) cells to the level of the CD177(neg) cells. Our data demonstrate the importance of the CD177:PR3 membrane complex in maintaining a high ANCA epitope density and thereby underscore the contribution of CD177 to the severity of PR3-ANCA diseases

Disrupting the CD177:proteinase 3 membrane complex reduces anti-PR3 antibody-induced neutrophil activation

CD177 is a neutrophil-specific receptor presenting proteinase 3 (PR3) autoantigen on the neutrophil surface. CD177 expression is restricted to a neutrophil subset resulting in CD177(pos)/mPR3(high) and CD177(neg)/mPR3(low) populations. The size of the CD177(pos)/mPR3(high) subset has implications for anti-neutrophil cytoplasmic autoantibody (ANCA)-associated autoimmune vasculitis (AAV) where patients harbor PR3-specific ANCA that activate neutrophils for degranulation. We generated high affinity anti-CD177 monoclonal antibodies, some of which interfered with PR3 binding to CD177 (PR3 "blockers") as determined by surface plasmon resonance spectroscopy, and used them to test the effect of competing PR3 from the surface of CD177(pos) neutrophils. Because intact anti-CD177 antibodies also caused neutrophil activation, we prepared non-activating Fab fragments of a PR3 blocker and non-blocker that bound specifically to CD177(pos) neutrophils by flow cytometry. We observed that Fab blocker clone 40, but not non-blocker clone 80, dosedependently reduced anti-PR3 antibody binding to CD177(pos) neutrophils. Importantly, preincubation with clone 40 significantly reduced respiratory burst in primed neutrophils challenged either with monoclonal antibodies to PR3 or PR3- ANCA IgG from AAV patients. After separating the two CD177/mPR3 neutrophil subsets from individual donors by magnetic sorting, we found that PR3-ANCA provoked significantly more superoxide production in CD177(pos)/mPR3(high) than in CD177(neg)/mPR3(low) neutrophils, and that anti- CD177 Fab clone 40 reduced the superoxide production of CD177(pos) cells to the level of the CD177(neg) cells. Our data demonstrate the importance of the CD177:PR3 membrane complex in maintaining a high ANCA epitope density and thereby underscore the contribution of CD177 to the severity of PR3-ANCA diseases

Plasma exchange for primary autoimmune autonomic failure

We report on a patient with long-standing severe autonomic failure that affected his sympathetic and parasympathetic nervous systems. Antibodies against the ganglionic acetylcholine receptors were detected in the serum. Removal of the antibodies by means of plasma exchange resulted in a dramatic clinical improvement