Kidney and haemostasis.

Renal insufficiency is characterized by thrombocytopathy, caused by the accumulation of water soluble and protein bound waste products of protein metabolism, which are not adequately eliminated by the kidney. The kidneys also excrete drugs and their metabolites, which accumulate if dosages are not adjusted to the renal function and may cause clinically relevant bleeding (i. e. synthetic penicillins, vitamin K antagonists, new oral anticoagulants). Therefore, each patients kidney function (GFR) ought to be evaluated by the KDIGO guidelines. The survival of chronic renal patients is lowered by increasing cardiovascular complications. Particularly frequent is non-valvular atrial fibrillation. The recommended prophylaxis with vitamin K antagonists for renal insufficiency is hampered by increased bleeding as well as by augmented (coronary) vascular and valvular calcification. It is not known yet whether prophylaxis with vitamin K may prevent this complication. CONCLUSION: Because new oral anticoagulants are equally or even more effective and cause less bleeding, they may be favoured in future and even in end-stage renal failure if more is known about dosing, safety and efficacy. The measurement of serum FGF 23 concentration may be helpful as a marker for their use.

Kidney and haemostasis. A (personal) time-journey.

UNLABELLED: Renal insufficiency is characterized by thrombocytopathy, caused by the accumulation of water soluble and protein bound waste products of protein metabolism, which are not adequately eliminated by the kidney. The kidneys also excrete drugs and their metabolites, which accumulate if dosages are not adjusted to the renal function and may cause clinically relevant bleeding (i. e. synthetic penicillins, vitamin K antagonists, new oral anticoagulants). Therefore, each patients kidney function (GFR) ought to be evaluated by the KDIGO guidelines. The survival of chronic renal patients is lowered by increasing cardiovascular complications. Particularly frequent is non-valvular atrial fibrillation. The recommended prophylaxis with vitamin K antagonists for renal insufficiency is hampered by increased bleeding as well as by augmented (coronary) vascular and valvular calcification. It is not known yet whether prophylaxis with vitamin K may prevent this complication. CONCLUSION: Because new oral anticoagulants are equally or even more effective and cause less bleeding, they may be favoured in future and even in end-stage renal failure if more is known about dosing, safety and efficacy. The measurement of serum FGF 23 concentration may be helpful as a marker for their use.

Henoch-Schönlein purpura in adults is not uncommon in elderly patients with an adverse prognosis.

BACKGROUND: Henoch-Schönlein purpura (HSP) is a fairly common disease in children and adolescents. There are only limited data available for adults. METHODS: A retrospective analysis was conducted to study renal manifestations in patients with HSP treated in our institution between 1982 and 2007. We divided our adult cohort according to age - under or over 60 years - to examine differences in elderly patients. RESULTS: HSP was identified in 2.2% of patients referred to us for kidney biopsy. Purpuric lesions and renal involvement were found in all patients. An important triggering factor for the development of HSP in our series was chronic alcohol intake. Forty percent of our patients fulfilled the WHO criteria for alcoholics. Renal involvement was particularly prominent in patients over 60 years of age. At disease onset, estimated glomerular filtration rate (eGFR) was 63% lower in the elderly. Within a median follow-up of 8 years, renal function was significantly better in younger adults than in the elderly. 32% of the elderly have shown Modification of Diet in Renal Disease (MDRD) < 20 ml/min/1.73 m2 in contrast to only 7% in patients < 60 years. Furthermore, significantly more elderly patients reached end-stage renal failure. CONCLUSION: The data indicate that renal manifestation of HSP in the elderly is severe and its outcome relatively poor, and worsens when compared to patients < 60 years.

Optimal blood pressure control versus additional immunosuppressive therapy in idiopathic membranous nephropathy - a retrospective analysis.

The treatment of idiopathic membranous nephropathy (MN) with nephrotic syndrome comprises immunosuppressive therapy and antihypertensive treatment with the blockade of the renin-angiotensin system (RAS). Given the relatively benign natural history of MN, an immunosuppressive-free therapeutic regimen should be considered as the primary treatment option. In a single-center, retrospective analysis we compared the outcome of 54 patients with biopsy-proven idiopathic MN 12, 24 and 60 months after initiation of therapy. All patients had RAS-blocking agents and 36 patients received additionally an immunosuppressive regimen. In both groups the patients initially had a nephrotic proteinuria (median 8.7 vs. 6.0 g/day, n.s.). Median blood pressure reduction was comparable after 12, 24 and 60 months in both groups. The median evolution of proteinuria during therapy after 12, 24 and 60 months was 3.4, 1.7 and 1.1 g/day in the group with immunosuppression compared to 3.0, 1.1 and 0.32 g/day in the non-immunosuppressive group. After 60 months no patient developed endstage renal failure. The number of severe side effects was significantly higher in patients with immunosuppression. Regarding renal function and reduction of proteinuria, patients with idiopathic MN treated without immunosuppressive therapy but with measures to ensure optimal blood pressure control and the full blockade of RAS had a similar outcome after 60 months as compared to patients who received additional immunosuppressive therapy.

Expression of CD57 on CD8+ T lymphocytes of patients with Wegener's granulomatosis and microscopic polyangiitis: evidence for continuous activation of CD8+ cells.

OBJECTIVES: To gain insight into the immune pathogenesis of Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA), the prevalence of circulating CD8+ T lymphocytes expressing CD57 as a marker for previous activation was analyzed. METHODS: Receptor expression of CD57 was measured in CD8+ T cells of patients with active disease (n=5) by cytofluorometry and compared with expression in patients in remission (n=80) and in age-matched healthy donors (n=34). The results were compared to clinical parameters including severity and duration of the disease. RESULTS: CD8+CD57+ were detected in patients with WG and MPA and in healthy donors as well and increased considerably with age. Compared to age-matched healthy donors, the prevalence of CD8+CD57+ was increased in the younger patients (up to 40 y). In most patients a high percentage of CD8+CD57+ coincided with severe disease and multiple organ involvement, while low CD8+CD57+ percentage was seen in patients with limited disease or in patients in complete remission. In patients with smoldering disease, the percentage of CD8+CD57+ increased with time. High numbers of CD8+CD57+ correlated with low CD4:CD8 ratio. CONCLUSIONS: In patients with WG and MPA a population of CD8+CD57+ expand, identifying terminally differentiated CD8+ cells. The prevalence of CD57+ cells was related to the course of disease. So far, the function of CD57 on CD8+ cells is not understood. However, these cells might produce certain cytokines, which play a role in the pathogenesis of AAV. The data support the hypothesis that CD8+ T cells are activated in the context of primary vasculitides.

T lymphocytes in patients with primary vasculitis: expansion of CD8+ T cells with the propensity to activate polymorphonuclear neutrophils.

OBJECTIVES: To gain insight into the immune pathogenesis of primary ANCA-associated vasculitides, the prevalence of circulating T lymphocytes expressing CD11b as a marker for activation was analysed in patients with WG or microscopic polyangiitis. METHODS; Receptor expression and IFNgamma synthesis were measured in T cells of patients with active disease by cytofluorometry and compared with expression in patients in remission and in healthy donors. RESULTS: During active disease, a small but conspicuous population of CD8+CD28+CD11b+ was found which produced IFNgamma. In healthy donors and in patients in remission or undergoing immunosuppressive therapy, CD11b was exclusively associated with CD8+CD28- cells, the latter being more frequent in patients with long-lasting or severe disease. In vitro experiments confirmed that CD11b is up-regulated when T cells are activated. After multiple rounds of restimulation, the CD11b expression persists whereas CD28 expression is lost, compatible with the notion that CD8+CD28+CD11b+ represents a transient phenotype in the course of T-cell activation. The IFNgamma-producing T cells activated polymorphonuclear neutrophils (PMN) to express MHC class II, thus generating the same PMN phenotype as in patients with active ANCA-associated vasculitis. A similar PMN phenotype could be generated by cultivation with supernatants of activated T cells or by IFNgamma alone, but not by antibodies to proteinase 3. CONCLUSIONS: In active primary vasculitis, a small population of CD8+ T cells, identified by the expression of CD11b, expands, producing IFNgamma. These T cells could activate PMN, thus generating a long-living and potentially destructive PMN phenotype.

Anti-chromatin and anti-C1q antibodies in systemic lupus erythematosus compared to other systemic autoimmune diseases.

OBJECTIVE: To evaluate the prevalence, sensitivity, and specificity of anti-chromatin and anti-C1q antibodies in systemic lupus erythematosus (SLE) and lupus nephritis compared to small vessel vasculitis and other connective tissue diseases. To provide long-term follow-up data for anti-chromatin antibodies in lupus nephritis. METHODS: We determined the significance of anti-nuclear antibodies (ANA), anti- double-stranded DNA (anti-dsDNA), anti-chromatin, and anti-C1q antibodies, as well as complement factors C3 and C4, in relation to disease activity in SLE patients with (n = 47; long-term follow-up data for 33 patients) and without (n = 31) biopsy-confirmed lupus nephritis, microscopic polyangiitis (n = 37), Wegener's granulomatosis (n = 66), primary Sjögren's syndrome (n = 17), limited scleroderma (CREST syndrome) (n = 6), and progressive systemic scleroderma (PSS) (n = 11). RESULTS: Anti-chromatin antibodies were more specific and sensitive than anti-C1q antibodies in distinguishing SLE patients from those with other systemic autoimmune diseases [anti-chromatin: sensitivity 64.1%, specificity 99.2%, odds ratio (OR) 219.6; anti-C1q: sensitivity 50%, specificity 72.6%, OR 2.65]. Anti-C1q antibodies were present in 75% of patients with Sjögren's syndrome and 35.1% of patients with microscopic polyangiitis. Anti-chromatin antibodies could identify SLE in patients with positive ANA but negative anti-dsDNA antibodies. Persisting anti-chromatin antibodies indicated SLE disease activity, even if anti-dsDNA antibodies had become negative. In long-term follow-up, those SLE patients with negative anti-dsDNA antibodies but persisting ANA and anti-chromatin antibodies relapsed if immunosuppression had been tapered. Anti-chromatin antibodies correlated with the SLE disease activity index (SLEDAI) as a marker of disease activity. CONCLUSIONS: The measurement of anti-chromatin, but not anti-C1q, antibodies in patients with systemic autoimmune diseases increases diagnostic sensitivity and specificity for SLE and assists in treatment decisions in anti-dsDNA-negative patients.

The pathogenesis of ANCA-associated vasculitides: old hypotheses and new insights.

The pathomechanism of the ANCA-associated vasculitides is discussed in light of the abstracts presented at the ANCA- and Vasculitis Workshop 2005 in Heidelberg!

Cyclophosphamide treatment in systemic necrotizing vasculitis and lupus nephritis. How long? How much?

The gold standard for inducing remission in systemic necrotizing vasculitis (SNV) and severe lupus nephritis is (and remains) the combination of cyclophosphamide and glucocorticoids. Long-term treatment with cyclophosphamide is limited because of toxicity. Recent prospective studies in antineutrophil cytoplasmic antibody (ANCA)-associated SNV revealed that after achievement of clinical remission (usually within 3-4 months after starting cyclophosphamide) cyclophosphamide can be replaced by azathioprine with no increase in relapse rates if treatment is continued for at least 1 year. Methotrexate is inferior to cyclophosphamide because of increased relapse rates-particularly in those with renal involvement-during follow-up. An ongoing study comparing mycophenolate mofetil (MMF) with azathioprine will clarify whether MMF is as successful as azathioprine or even better. The concomitant use of tumor necrosis factor (TNF)-alpha blockers increases the efficacy of immunosuppression. TNF-alpha blockers may be added if SNV is refractory to standard immunosuppressive therapy. However, with this addition to therapy, systemic infections are more frequent. In patients with severe lupus nephritis (WHO IV) the efficacy of combined i.v. therapy with cyclophosphamide and glucocorticoids was shown by NIH trials. This NIH regimen competes with the EURO-Lupus nephritis schedule with a lower dose of i.v. cyclophosphamide followed by maintenance therapy with azathioprine. Long-term follow-up is, however, still lacking in the EURO-Lupus trial. Ongoing prospective studies will reveal whether cyclophosphamide may be substituted by MMF from the very beginning or whether MMF is superior to azathioprine during maintenance therapy of lupus nephritis.

Improved clinical outcome of lupus nephritis during the past decade: importance of early diagnosis and treatment.

OBJECTIVE: To evaluate the differences in the outcome of lupus nephritis diagnosed either in the 1980s or the 1990s in Heidelberg, Germany. METHODS: Fifteen patients with biopsy confirmed lupus nephritis (LN) were followed up between 1980 and 1989 and 41 patients were followed up between 1990 and 2000. Their status at diagnosis and their treatment schedules and outcome were analysed. 68% had WHO IV nephritis. RESULTS: In the decade from 1990 to 2000 there was significantly less proteinuria (46 v 17 g/l, p=0.008), significantly lower rates of renal failure (40% v 17%, p=0.02), and fewer histological signs of chronicity (33% v 10%, p=0.01) at the time of diagnosis of LN than in the decade from 1980 to 1989. The mean (SD) time from the first appearance of proteinuria until kidney biopsy was significantly shorter in the later decade (15.4 (15.6) v 3.9 (4.7) months). Although treatment schedules were not significantly different, the outcome of the disease was significantly better in the patients who were diagnosed with LN between 1990 and 2000 (p=0.045). Whereas 6/15 (40%) patients between 1980 and 1989 had terminal renal failure after a mean time of 94 months, in the group of 1990-2000 no patient developed terminal renal failure (median observation time 24 months). In both groups one patient died from infection. A high chronicity index in histology and the presence of arterial hypertension or renal failure, or both, at the time of diagnosis were significant risk factors for the development of terminal renal failure in the course of the disease. CONCLUSIONS: The outcome of patients with newly diagnosed LN was significantly better between 1990 and 2000 than between 1980 and 1989. Kidney damage and chronic histological changes at time of diagnosis were significantly less common between 1990 and 2000, which is attributable to earlier diagnosis and treatment in the later decade.

Up-regulation of the dendritic cell marker CD83 on polymorphonuclear neutrophils (PMN): divergent expression in acute bacterial infections and chronic inflammatory disease.

Upon cultivation with interferon-gamma (IFN-gamma ) and granulocyte/macrophage-colony stimulating factor (GM-CSF) polymorphonuclear neutrophils (PMN) acquire characteristics of dendritic cells, including expression of major histocompatibility complex (MHC) class II antigens, of the co-stimulatory antigens CD80, CD86 and of CD83, the latter considered to be specific for dendritic cells. Dendritic-like PMN were also able to present to T cells antigens in a MHC class II-restricted manner. To assess whether dendritic-like PMN are also generated in vivo, cells of patients with acute bacterial infections and of patients with chronic inflammatory diseases (primary vasculitis) were tested. During acute infection up to 80% of PMN acquired CD83, but remained negative for MHC class II, CD80 or CD86. PMN of patients with primary vasculitis expressed MHC class II antigens, CD80 and CD86, but not CD83, indicating that up-regulation of MHC class II and of CD83 are not necessarily linked to each other. Indeed, parallel studies with PMN of healthy donors showed that while IFN-gamma and granulocyte/macrophage colony stimulating factor (GM-CSF) induced both, MHC class II and CD83, tumour necrosis factor (TNF)-alpha selectively induced de novo synthesis of CD83. The function of CD83 on PMN is still elusive. A participation in the MHC class II-restricted antigen presentation could be ruled out, consistent with the segregation of MHC class II and CD83 expression. Regardless, however, of its function, CD83 expression could serve as a marker to differentiate between acute and chronic inflammation.

Treatment of life-threatening multiresistant staphylococcal and enterococcal infections in patients with end-stage renal failure with quinupristin/dalfopristin: preliminary report.

BACKGROUND: Life-threatening infections with multiresistant gram-positive bacteria are increasing. Treatment with quinupristin/dalfopristin (Q-D) has turned out to be effective against such resistant pathogens. PATIENTS AND METHODS: We report on treatment of six patients on dialysis (four with additional liver injury) and of one renal graft recipient with normal renal function who had severe infections caused by multiresistant Staphylococus epidermidis (1/7), methicillin-resistant Staphylococcus aureus (4/7) and vancomycin-resistant Enterococcus faecium (2/7). RESULTS: Six out of seven patients were cured by therapy with Q-D in adjusted doses lasting for 10 to 34 days. Pharmacokinetics of Q-D and its metabolites were determined and remained within the therapeutic range, despite a modest increase of all compounds at the presumed steady state. The concentrations of the metabolites of Q-D were clearly lower than the parent drugs, including those of quinupristin-conjugated derivatives, which has not been reported previously. CONCLUSION: These preliminary results suggest that: a) neither quinupristin nor dalfopristin or its metabolites accumulated despite the long duration of treatment; b) no adjustment of the standard dosage regimen (three times 7.5 mg/kg/day) is necessary in end-stage renal disease.

Erythropoietin-mediated decrease of the redox-sensitive transcription factor NF-kappaB is inversely correlated with the hemoglobin level.

The aim of this study was to determine the effect of rh-EPO on the redox-sensitive transcription factor (NF-kappaB) in vivo and in vitro. Ten patients (7 female, 3 male), mean age 69.2 +/- 11 years, with end-stage renal failure and anemia prior to initiation of regular hemodialysis were enrolled and divided into 2 groups (group A "good responder", 7 patients and group B "poor responder", 3 patients) in accordance to the response to rh-EPO therapy. Nuclear binding activity of NF-kappaB was determined in ex vivo isolated mononuclear cells before, 4 and 8 weeks after onset of regular hemodialysis and rh-EPO therapy by electrophoretic mobility shift assays (EMSA). In group A, a reduction of NF-KB binding activity from 100% to 56 +/- 6% was observed within the first four weeks of rh-EPO treatment, while mean hemoglobin rose from 8.2 +/- 0.4 g/dl to 11.1 +/- 0.2 g/dl. However, this effect was abrogated after another 4 weeks of treatment when NF-kappaB signal increased back to 85.2 +/- 10.6% despite consistent mean hemoglobin level of 11.3 +/- 0.4 g/dl. Group B demonstrated a slight increase of NF-kappaB signal from 100% to 129 +/- 18.5%, while mean hemoglobin only moderately rose from 7.6 +/- 0.3 g/dl to 8.3 +/- 0.1 g/dl within the first 4 weeks, and it further rose to 180 +/- 45% after 8 weeks of treatment, while mean hemoglobin (9.5 +/- 0.1 g/dl) remained low. The NF-kappaB binding activity differed significantly when comparing both groups (p = 0.007). Binding activity of Oct-1, serving as control, did not change notably in either group (p = 0.34). In vitro studies showed that rh-EPO did not directly affect NF-KB binding activity in THP-1 cells. However, coincubation of THP-1 cells with erythrocytes led to a reduction of NF-kappaB binding activity only in THP-1 cells with a hemoglobin level adjusted to 11 g/dl compared to 8 g/dl in the presence of rh-EPO. In vivo and in vitro data implicate a complex interaction between rh-EPO, stimulated RBC and the redox-sensitive transcription factor NF-kappaB in mononuclear cells.

Polymorphonuclear neutrophils in Wegener's granulomatosis acquire characteristics of antigen presenting cells.

BACKGROUND: Constitutive expression of major histocompatibility complex (MHC) class II antigens and of the co-stimulatory receptors CD80 and CD86 is restricted to professional antigen presenting cells. Polymorphonuclear neutrophils (PMN) of healthy donors are negative for those antigens. Our recent study, however, found that PMN of patients with active Wegener's granulomatosis acquired MHC class II antigens. METHODS: To continue and extend the previous study results, PMN and monocytes of 60 patients with Wegener's granulomatosis, 24 patients with microscopic polyangiitis (MPA), 20 patients with acute bacterial infection, and 53 healthy donors were analyzed for the expression of MHC class II antigens as well as of CD80 and CD86. Moreover, induction on PMN of MHC class II expression was studied, as was antigen presentation as a possible functional consequence. RESULTS: PMN of patients with acute, active Wegener's granulomatosis expressed MHC class II antigens, CD80 and CD86; on monocytes up-regulation of MHC class II was seen. In contrast, PMN of patients with inactive disease, or with relapse, patients with microscopic polyangiitis or with bacterial infections expressed neither MHC class II, nor CD80 or CD86. PMN of healthy donors acquired these antigens when cultured in the presence of T cells or T cell-derived cytokines. The PMN were then able to present to T cell antigens in a MHC-class II restricted manner. CONCLUSION: During active disease, the PMN of patients with Wegener's granulomatosis acquire characteristics of antigen presenting cells, whereas the PMN of patients with MPA or bacterial infection do not. The finding reflects differences in the pattern of the respective inflammatory response and suggests new effector functions of PMN. Moreover, MHC class II expression on PMN could serve as a novel marker for active Wegener's granulomatosis.

Transdifferentiation of polymorphonuclear neutrophils: acquisition of CD83 and other functional characteristics of dendritic cells.

Polymorphonuclear neutrophils (PMN) are in the first line of defense against bacterial infections. They are considered to be end-differentiated cells undergoing constitutive apoptosis within hours after release from the bone marrow. During pathological events, however, their life span is extended in conjunction with morphological and functional alterations indicative of a transdifferentiation of mature PMN. To further characterize differentiated PMN, the alterations seen in vivo were reproduced by cultivating PMN of healthy donors with either gamma-interferon, granulocyte/macrophage colony stimulating factor, or a combination thereof. Thus cultivated cells escaped from apoptosis, and protein synthesis was induced, notably of the major histocompatibility complex (MHC) class II antigens, CD80 and CD86. Moreover, CD83, thought to be specific for dendritic cells was synthesized, while typical markers of PMN, including CD66b, CD11a/CD11b/CD11c, CD15, CD18 were preserved. A profound alteration of both cellular morphology and of function was seen: the cultivated PMN lost their chemotactic activity but had acquired the ability to present to T-cells a peptide antigen in a MHC class II restricted manner. The data lead to the conclusion that mature PMN can differentiate further to cells with characteristics of DCs, thereby connecting PMN to the specific T-cell response.

Polymorphonuclear neutrophils as accessory cells for T-cell activation: major histocompatibility complex class II restricted antigen-dependent induction of T-cell proliferation.

Polymophonuclear cells (PMN) of healthy donors do not express major histocompatibility complex (MHC) class II antigens or the T-cell costimulatory molecules CD80 or CD86. Expression of these receptors, however, is seen in patients with chronic inflammatory diseases. We now report that, by culturing PMN of healthy donors with autologous serum, interferon-gamma (IFN-gamma) and granulocyte-macrophage colony-stimulating factor (GM-CSF), de novo synthesis of MHC class II, CD80 and CD86 could be induced. MHC class II-positive PMN acquired the capacity to present staphylococcus enterotoxin to peripheral T cells, apparent as induction of interleukin-2 (IL-2) synthesis and proliferation of the T cells. Moreover, the PMN also processed tetanus toxoid (TT) and induced proliferation of TT-specific T cells in a MHC class II-restricted manner. Taken together, these data indicate that PMN can be activated to function as accessory cells for T-cell activation.

[Vasculitis 1998: new aspects in diagnosis and therapy]. / Vaskulitis 1998: Neue Aspekte zu Diagnostik und Therapie.

The Chapel Hill conference established the most actual classification of systemic vasculitides. Disease activity and organ damage were standardized by means of a new scoring system (BVAS; VDI). Bacterial infection is frequent during the active phase of vasculitis. The measurement of serum procalcitonin helps to differentiate between disease activity and infection. In a recent study the European vasculitis group (EC-BCR project) found that the presence of C-ANCA/PR 3-ANCA or P-ANCA/MPO-ANCA is as reliable as histological proof of vasculitis. In rare cases ANCA is positive in diseases other than vasculitis, which has to be kept in mind for diagnosis and therapy. The association between ANCA and IgA nephropathy is exciting. The occurrence of IgA-GN in patients with Wegener's granulomatosis is usually a secondary event whereas in patients with rapidly progressive IgA-GN microscopic polyangiitis follows. Many observations support the view that ANCA-positive vasculitides are T-cell mediated diseases. Our investigations demonstrate that neutrophils express class II antigens during active disease and are able to trigger T-cell activation via infectious stimuli. With regard to therapy of ANCA-positive vasculitides several strategies are currently being examined in different European countries (EUVAS) with the aim to limit cyclophosphamide to the active stage of the disease.