Martin Nitschke

Local Generation of C-Reactive Protein in Diseased Coronary Artery Venous Bypass Grafts and Normal Vascular Tissue

Background—Venous coronary artery bypass grafts (CABGs) are prone to accelerated atherosclerosis. In atherosclerotic diseases, serum C-reactive protein (CRP) levels have become an important diagnostic and prognostic marker. The origin of CRP in this setting remains to be elucidated. Methods and Results—Monoclonal anti-CRP identified CRP expression in medial and intimal &agr;-actin–positive smooth muscle cells (SMCs) of diseased CABGs with type V and VI lesions and also of native saphenous veins of atherosclerotic individuals. In addition, patent coronary arteries with type IV and V but not with type I through III lesions exhibited intense SMC staining for CRP. Calcified desobliterates of occluded coronary arteries with end-stage disease did not show SMC staining for CRP and were consistently negative for CRP mRNA, as detected by means of real-time polymerase chain reaction. However, CRP mRNA was expressed in 11 of 15 diseased CABGs and also in 10 of 15 native veins. By contrast, only 3 of 18 internal mammary and 4 of 12 radial arteries with virtually no atherosclerosis were positive for CRP mRNA. Conclusions—CRP is produced by SMCs of atherosclerotic lesions with active disease but not in end-stage plaques. The role of CRP constitutively expressed by normal vascular tissue in vein graft disease has yet to be elucidated.

Association Between Azithromycin Therapy and Duration of Bacterial Shedding Among Patients With Shiga Toxin–Producing Enteroaggregative Escherichia coli O104:H4

CONTEXT An outbreak of Shiga toxin-producing enteroaggregative Escherichia coli (STEC O104:H4) infection with a high incidence of hemolytic uremic syndrome (HUS) occurred in Germany in May 2011. Antibiotic treatment of STEC infection is discouraged because it might increase the risk of HUS development. However, antibiotic therapy is widely used to treat enteroaggregative E coli infection. In the German outbreak, a substantial number of patients received prophylactic azithromycin treatment as part of a therapeutic regimen with the C5 antibody eculizumab. OBJECTIVE To analyze the duration of bacterial shedding in patients with STEC infection who did and did not receive oral azithromycin therapy. DESIGN, SETTING, AND PATIENTS At a single center in Lübeck, Germany, 65 patients with STEC infection, including patients with HUS as well as STEC-infected outpatients without manifestation of HUS, were investigated between May 15 and July 26, 2011, and were monitored for a mean of 39.3 days after onset of clinical symptoms. MAIN OUTCOME MEASURE Carriage of STEC after azithromycin therapy. RESULTS Twenty-two patients received oral azithromycin and 43 patients did not receive antibiotic treatment. Among antibiotic-treated patients, long-term STEC carriage (>28 days) was observed in 1 of 22 patients (4.5%; 95% CI, 0%-13.3%) compared with 35 of 43 patients (81.4%; 95% CI, 69.8%-93.0%) who were not treated with antibiotics (P < .001). All 22 patients receiving azithromycin treatment had at least 3 STEC-negative stool specimens after the completion of treatment, and no recurrence of STEC was observed in these patients. As proof of principle, 15 patients who initially were not treated with antibiotics and were long-term STEC carriers were treated with oral azithromycin given for 3 days and subsequently had negative stool specimens. CONCLUSION Treatment with azithromycin was associated with a lower frequency of long-term STEC O104:H4 carriage.

Recommendations for the use of rituximab (anti-CD20 antibody) in the treatment of autoimmune bullous skin diseases.

Autoimmune bullous skin disorders are induced by autoantibodies against distinct adhesion complexes of the epidermal and dermal‐epidermal junction. Since most of these disorders are characterized by a severe, potentially lethal course,they require long‐term immunosuppressive treatment to reduce the de novo synthesis of pathogenic autoantibodies by B lymphocytes. Rituximab, a chimeric monoclonal antibody against CD20 on B lymphocytes, has shown promise in several case reports or cohort studies in the treatment of paraneo‐plastic pemphigus,refractory cases of pemphigus vulgaris and foliaceus and in other autoimmune bullous disorders.Treatment with rituximab leads to depletion of pathogenic B‐cells which may last up to 12 months resulting in a reduction of plasma cells secreting pathogenic autoantibodies.Rituximab is usually administered in an adjuvant setting at a dose of 375 mg/m2 i.v.in weekly intervals for four consecutive weeks in addition to the standard immunosuppressive treatment.The present consensus statement of German‐speaking derma‐tologists,rheumatologists and oncologists summarizes and evaluates the current evidence for the use and mode of application of rituximab in autoimmune bullous skin disorders.

Valganciclovir prophylaxis versus preemptive therapy in cytomegalovirus-positive renal allograft recipients: 1-year results of a randomized clinical trial.

Background. Cytomegalovirus (CMV) prevention can be achieved by prophylaxis or preemptive therapy. We performed a prospective randomized trial to determine whether renal transplant recipients with a positive CMV serostatus (R+) had a higher rate of CMV infection and disease after transplantation when treated preemptively for CMV infection, compared with primary valganciclovir prophylaxis. Methods. Prophylaxis was 2×450 mg oral valganciclovir/day for 100 days; preemptive patients were monitored by CMV-polymerase chain reaction (PCR), and after a positive PCR test received 2×900 mg valganciclovir/day for at least 14 days followed by secondary prophylaxis. Valganciclovir dosage was adjusted according to renal function. Patients are followed up for 5 years and initial 12-month data are presented. Two hundred and ninety-six recipients were analyzed (168 donor/recipient seropositive [D+/R+], 128 donor seronegative/recipient seropositive [D−/R+]; 146 receiving prophylaxis and 150 preemptive therapy). Results. Overall, CMV infection (asymptomatic CMV viral load ≥400 CMV DNA copies/mL proven by CMV-PCR) was significantly higher in recipients under preemptive therapy (38.7% vs. 11.0%, P<0.0001), with the highest incidence in D+/R+ preemptive patients (53.8% vs. 15.6%, P<0.0001). D+/R+ recipients with preemptive therapy also had the highest rate of CMV disease (CMV syndrome and tissue-invasive disease that was clinically diagnosed and biopsy proven) (19.2% vs. 4.4%, P=0.003). Renal function assessed by creatinine clearance was similar for both groups. Graft loss occurred in 7 vs. 4 patients on preemptive versus prophylactic therapy (P>0.05). Tolerability was similar for both treatment groups. Conclusions. Oral valganciclovir prophylaxis significantly reduces CMV infection and disease, particularly for D+/R+ patients. Hence, our study supports routine prophylaxis for all D+/R+ recipients.

Treatment of severe pemphigus with protein A immunoadsorption, rituximab and intravenous immunoglobulins.

Background  Pemphigus is a life‐threatening autoimmune blistering disease usually treated with high‐dose corticosteroids and other immunosuppressants. However, this regimen may prove inadequate in severe cases and cause dangerous side‐effects. While protein A immunoadsorption (PAIA) induces a rapid remission in severe pemphigus, the disease usually recurs once the treatment is stopped. In contrast, anti‐CD20 antibody rituximab has a delayed onset of action but may lead to a long‐term remission of pemphigus.

Recommendations for the use of immunoapheresis in the treatment of autoimmune bullous diseases

Despite the use of high‐dose systemic corticosteroids in combination with other immunosuppressants, in some patients with autoimmune bullous diseases only insufficient improvement is achieved. In these cases and in acute severe disease, adjuvant immunoapheresis has been increasingly used. A consensus meeting was held in mid‐2005 in Hamburg, aiming at developing guidelines for the use of immunoapheresis in the treatment of autoimmune bullous diseases.This paper summarizes the experts‘ recommendations.

Improvement of treatment-refractory atopic dermatitis by immunoadsorption: a pilot study.

CCDs. Similar to previous studies, about 50% of patients with DP had IgE to CCDs, explaining DP at least in some patients. In current clinical practice immunotherapy with both BVand VV, is usually performed in patients who had not identified the culprit insect but display DP to venom extracts, especially in patients without IgE to CCDs. The present study, however, demonstrates that only a minority of CCD-negative patients with DP to venom extracts (8/33 [24%]) display a genuine sensitization to both SSMAs, whereas the majority (22/33 [66%]) present a sensitization only to one of the SSMAs (Fig 1). In the latter group immunotherapy only with venom from the primary sensitizing insect should be sufficient, and it is unlikely that immunotherapy with the second venom would be of additional benefit. In conclusion, detection of specific IgE to rApi m 1 and rVes v 5 is a reliable diagnostic method that enables us discriminate between genuine double sensitization and cross-reactivity in patients with double-positive IgE results to conventional venom extracts. This way it allows us to optimize patient selection for immunotherapy and to avoid unnecessary treatment protocols with both insect venoms. Silke C. Hofmann, MD* Nikolai Pfender* Steffi Weckesser, MD Johannes Huss-Marp, MD Thilo Jakob, MD

Bactericidal Activity of Renal Tubular Cells: The Putative Role of Human β-Defensins

Renal tubular epithelial cells (RTC) form a barrier between the host and ascending microbes in upper urinary tract infection. Previous studies have shown the ability of the kidney to produce defensins – antimicrobial peptides that play a pivotal role in unspecific host defense. To further clarify the role of renal epithelium for direct antibacterial activity we investigated the expression, regulation and production of antimicrobial peptides by cultured human RTC. Cell culture supernatants of RTC exert strong bactericidal activity against Escherichia coli and Klebsiella pneumoniae, two of the most important pathogens in urinary tract infections. The antimicrobial effect depends on salt concentration, a typical feature of human defensins. RT-PCR of RNA from cultured proximal and distal RTC showed constitutive expression of human β-defensin 1 (hbd-1) and human β-defensin 2 (hbd-2) whereas only hbd-1 expression could be detected in RNA preparation from renal biopsy material. Hbd-2 expression of RTC was induced by inflammatory processes as shown by semiquantitative competitive RT-PCR. Coincubation of the cultured cells with IL-1α or E. coli promote the strongest hbd-2 induction whereas TNF-α and LPS lead to a weaker or no (IL-6) hbd-2 induction. This is the first evidence that human RTC are able to produce antibacterial substances in a biologically relevant amount and that β-defensins are candidate proteins responsible for this effect.

Slowing the progression of chronic allograft nephropathy by conversion from cyclosporine to tacrolimus: a randomized controlled trial.

Background. Chronic allograft nephropathy (CAN) is a multifactorial process with immunologic and nonimmunologic factors. Because tacrolimus (Tac) has been ascribed a beneficial effect on some of these factors when compared to cyclosporine A (CyA), a randomized controlled trial was conducted to investigate whether conversion from CyA to Tac can ameliorate the progression of renal dysfunction in kidney transplant recipients (KTR) with CAN. Methods. Of the 46 patients with biopsy-proven CAN enrolled, 24 were converted from CyA to Tac, whereas 22 patients were maintained on CyA. Serum creatinine (SCrea), lipid profiles and an antihypertensive score (AHS) were determined after 3, 6 and 12 months. AHS is based on the total number and dosages of antihypertensive medications used. SCrea and AHS were additionally evaluated at 36 months. Results. SCrea was decreased in the Tac group (Tacbaseline: 297±67 &mgr;mol/L; Tac6: 261±70 &mgr;mol/L, P<0.001; Tac12: 254±55 &mgr;mol/L, P<0.001; Tac36: 255±78 &mgr;mol/L, P=0.235), whereas a significant increase of SCrea was detected in the CyA group (CyAbaseline: 279±77 &mgr;mol/L, CyA12: 333±98 &mgr;mol/L, P<0.001; CyA36: 317±89 &mgr;mol/L, P<0.001). Compared to CyA therapy, SCrea in the Tac group declined after 12 and 36 months (P=0.011 and 0.048, respectively) as well as AHS (Tac12: 59±13, CyA12: 83±14, P<0.001; Tac36: 60±12, CyA36: 84±14, P<0.001). LDL cholesterol was lower in the Tac group after 12 months (Tac12: 2.5±0.5mmol/L, CyA12: 3.5±0.6mmol/L, P<0.001). Conclusion. Conversion from CyA to Tac in KTR with CAN improves allograft function, lowers blood pressure, and reduces LDL cholesterol. This superior profile may translate into improved long-term graft survival.

The CD40-CD40L Pathway Contributes to the Proinflammatory Function of Intestinal Epithelial Cells in Inflammatory Bowel Disease

In inflammatory bowel diseases (IBD), intestinal epithelial cells (IECs) are involved in the outbalanced immune responses toward luminal antigens. However, the signals responsible for this proinflammatory capacity of IECs in IBD remain unclear. The CD40/CD40L interaction activates various pathways in immune and nonimmune cells related to inflammation and was shown to be critical for the development of IBD. Here we demonstrate CD40 expression within IECs during active IBD. Endoscopically obtained biopsies taken from Crohns disease (n = 112) and ulcerative colitis patients (n = 67) consistently showed immunofluorescence staining for CD40 in IECs of inflamed ileal or colonic mucosa. In noninvolved mucosa during active disease, tissue obtained during Crohns disease or ulcerative colitis in remission and biopsies from healthy controls (n = 38) IECs almost entirely lacked CD40 staining. Flow cytometry and RT-PCR analysis using different intestinal epithelial cell lines (HT29, SW480, and T84) showed IFN-gamma to effectively induce CD40 in IECs. Cells were virtually unresponsive to LPS or whole E. coli regarding CD40 expression. In addition, a moderate induction of CD40 was found in response to TNF-alpha, which exerted synergistical effects with IFN-gamma. CD40 ligation by CD40L-transfected murine fibroblasts or soluble CD40L increased the secretion of IL-8 in IFN-gamma pretreated HT29 cells. Our findings provide evidence for the epithelial expression and modulation of CD40 in IBD-affected mucosa and indicate its involvement in the proinflammatory function of IECs.