Generation of Catalytic Antibodies Is an Intrinsic Property of an Individual's Immune System: A Study on a Large Cohort of Renal Transplant Patients.

Renal transplant is the treatment of choice for patients with terminal end-stage renal disease. We have previously identified low levels of catalytic IgG as a potential prognosis marker for chronic allograft rejection. The origin and physiopathological relevance of catalytic Abs is not well understood, owing to the fact that catalytic Abs have been studied in relatively small cohorts of patients with rare diseases and/or without systematic follow-up. In the current study, we have followed the evolution of the levels of catalytic IgG in a large cohort of renal transplant patients over a 2-y period. Our results demonstrate that, prior to transplant, patients with renal failure present with heterogeneous levels of IgG hydrolyzing the generic proline-phenylalanine-arginine-methylcoumarinamide (PFR-MCA) substrate. PFR-MCA hydrolysis was greater for patients' IgG than for a therapeutic preparation of pooled IgG from healthy donors. Renal transplant was marked by a drastic decrease in levels of catalytic IgG over 3 mo followed by a steady increase during the next 21 mo. Patients who displayed high levels of catalytic IgG pretransplant recovered high levels of catalytic Abs 2 y posttransplant. Interestingly, IgG-mediated hydrolysis of a model protein substrate, procoagulant factor VIII, did not correlate with that of PFR-MCA prior transplantation, whereas it did 12 mo posttransplant. Taken together, our results suggest that the level of circulating catalytic IgG under pathological conditions is an intrinsic property of each individual's immune system and that recovery of pretransplant levels of catalytic IgG is accompanied by changes in the repertoire of target Ags.

SIMulation of Medication Error induced by Clinical Trial drug labeling: the SIMME-CT study.

OBJECTIVE: To assess the impact of investigational drug labels on the risk of medication error in drug dispensing. DESIGN: A simulation-based learning program focusing on investigational drug dispensing was conducted. SETTING: The study was undertaken in an Investigational Drugs Dispensing Unit of a University Hospital of Lyon, France. PARTICIPANTS: Sixty-three pharmacy workers (pharmacists, residents, technicians or students) were enrolled. INTERVENTION: Ten risk factors were selected concerning label information or the risk of confusion with another clinical trial. Each risk factor was scored independently out of 5: the higher the score, the greater the risk of error. From 400 labels analyzed, two groups were selected for the dispensing simulation: 27 labels with high risk (score ≥3) and 27 with low risk (score ≤2). Each question in the learning program was displayed as a simulated clinical trial prescription. MAIN OUTCOME MEASURE: Medication error was defined as at least one erroneous answer (i.e. error in drug dispensing). For each question, response times were collected. RESULTS: High-risk investigational drug labels correlated with medication error and slower response time. Error rates were significantly 5.5-fold higher for high-risk series. Error frequency was not significantly affected by occupational category or experience in clinical trials. CONCLUSIONS: SIMME-CT is the first simulation-based learning tool to focus on investigational drug labels as a risk factor for medication error. SIMME-CT was also used as a training tool for staff involved in clinical research, to develop medication error risk awareness and to validate competence in continuing medical education.

The RISE Study: Retrospective Registry for the International Safety and Efficacy Results of Patent Foramen Ovale Closure with Figulla Flex Il PFO and UNI Occluders.

Background: Transcatheter closure of a patent foramen ovale (PFO) is performed in cryptogenic stroke and other conditions. Information is lacking for some devices. Methods: We aimed to evaluate the Figulla Flex II PFO Occluder (FFP) and Figulla Flex UNI Occluder (FFU) through a retrospective multi-center registry. Results: 527 patients were included. Mean age was 48.9 (±13.8) years. The procedure was under transthoracic, transesophageal or intracardiac echocardiography in 185 (35.1%), 193 (36.6%) and 149 (28.3%) cases, respectively, and under general anesthesia in 191 patients (36.2%). The FFP and FFU were used in 408 (77.4%) and 119 (22.6%) cases, respectively. The success rate was 99.1%. Median follow-up was 1.1 (0.5-2.5) years. A new atrial fibrillation/flutter within six months occurred in 14 (2.7%) cases, with no difference between devices. One device embolization in the pulmonary artery was identified two years post-procedure. Residual shunts occurred in 18 (6.9%) cases at 1 year, with TIA in three (16.6%) patients. Out of 437 patients with stroke/TIA, 260 (59%) were followed more than one year after closure. Median follow-up was 2.1 (1.17-3.1) years, with four recurrent strokes/TIA. Conclusions: The FFP and FFU devices are safe and effective for PFO closure, with very few atrial fibrillation/flutter and neurologic events, except in cases with a residual shunt.

Phenotype and genotype characterization of adenine phosphoribosyltransferase deficiency.

Adenine phosphoribosyltransferase (APRT) deficiency is a rare autosomal recessive disorder causing 2,8-dihydroxyadenine stones and renal failure secondary to intratubular crystalline precipitation. Little is known regarding the clinical presentation of APRT deficiency, especially in the white population. We retrospectively reviewed all 53 cases of APRT deficiency (from 43 families) identified at a single institution between 1978 and 2009. The median age at diagnosis was 36.3 years (range 0.5 to 78.0 years). In many patients, a several-year delay separated the onset of symptoms and diagnosis. Of the 40 patients from 33 families with full clinical data available, 14 (35%) had decreased renal function at diagnosis. Diagnosis occurred in six (15%) patients after reaching ESRD, with five diagnoses made at the time of disease recurrence in a renal allograft. Eight (20%) patients reached ESRD during a median follow-up of 74 months. Thirty-one families underwent APRT sequencing, which identified 54 (87%) mutant alleles on the 62 chromosomes analyzed. We identified 18 distinct mutations. A single T insertion in a splice donor site in intron 4 (IVS4 + 2insT), which produces a truncated protein, accounted for 40.3% of the mutations. We detected the IVS4 + 2insT mutation in two (0.98%) of 204 chromosomes of healthy newborns. This report, which is the largest published series of APRT deficiency to date, highlights the underdiagnosis and potential severity of this disease. Early diagnosis is crucial for initiation of effective treatment with allopurinol and for prevention of renal complications.

IVIg treatment reduces catalytic antibody titers of renal transplanted patients.

Catalytic antibodies are immunoglobulins endowed with enzymatic activity. Catalytic IgG has been reported in several human autoimmune and inflammatory diseases. In particular, low levels of catalytic IgG have been proposed as a prognostic marker for chronic allograft rejection in patients undergoing kidney transplant. Kidney allograft is a treatment of choice for patients with end-stage renal failure. Intravenous immunoglobulins, a therapeutic pool of human IgG, is used in patients with donor-specific antibodies, alone or in conjunction with other immunosuppressive treatments, to desensitize the patients and prevent the development of acute graft rejection. Here, we followed for a period of 24 months the levels of catalytic IgG towards the synthetic peptide Pro-Phe-Arg-methylcoumarinimide in a large cohort of patients undergoing kidney transplantation. Twenty-four percent of the patients received IVIg at the time of transplantation. Our results demonstrate a marked reduction in levels of catalytic antibodies in all patients three months following kidney transplant. The decrease was significantly pronounced in patients receiving adjunct IVIg therapy. The results suggests that prevention of acute graft rejection using intravenous immunoglobulins induces a transient reduction in the levels of catalytic IgG, thus potentially jeopardizing the use of levels of catalytic antibodies as a prognosis marker for chronic allograft nephropathy.

Effect of two injections of non-adjuvanted influenza A H1N1pdm2009 vaccine in renal transplant recipients: INSERM C09-32 TRANSFLUVAC trial.

BACKGROUND: Enhancing vaccine immunogenicity in kidney transplant recipients, particularly against influenza, is required since the immunosuppression used to prevent graft rejection limits vaccine immunogenicity. We therefore investigated the immunogenicity and safety of a double dose non-adjuvanted vaccination regimen against influenza H1N1pdm2009 in kidney transplant adult recipients. METHODS: A prospective single-arm study was conducted including 121 renal transplant recipients under triple immunosuppressive regimen. Patients received 2 injections (day 0, day 21) of an inactivated, non-adjuvanted H1N1pdm2009 vaccine. Immunogenicity (hemagglutination-inhibition [HI] antibodies and anti-hemagglutin [HA] specific T cells) was evaluated after one and two injections (day 21, day 42) and at 6 months (day 182). RESULTS: The seroprotection rate (HI antibody titer≥1/40) was 19% at day 0 (n=119), 53% at day 21 (n=118), 60% at day 42 (n=116) (p=0.013; day 42 vs. day 21) and 56% at day 182 (n=113). The seroconversion rate was 24% and 32%, the geometric mean fold rise was 3.7 and 4.6 after the first and second injections, respectively. T-cell immunity to the H1N1pdm2009 vaccine showed a two-fold increase from baseline, though not statistically significant, in H1N1pdm2009-HA-specific CD4+ and CD8+ T cells in 34% and 48% of cases, respectively. No rejection episodes related to vaccination were observed while the donor-specific antibodies and creatinine clearance remained unchanged throughout the study. CONCLUSION: Administration of two doses of the non-adjuvanted influenza H1N1pdm2009 vaccine in renal transplant patients is safe and induces a significant seroprotection, not strong enough yet to meet European or US requirements for adults below 60 years, but comparable to seroprotection levels usually observed in the non immunosuppressed elderly population or conferred by a single dose of adjuvanted vaccine in solid organ transplant recipients. These results provide useful indications for future strategies required to improve immunogenicity of vaccines against influenza in transplanted patients.