Acute rejection in kidney transplantation and the evaluation of associated polymorphisms (SNPs): the importance of sample size.

Background Acute rejection (AR) is one of the most frequent complications after kidney transplantation (KT). Scientific evidence reports that some single-nucleotide polymorphisms (SNPs) located in genes involved in the immune response and in the pharmacokinetics and pharmacodynamics of immunosuppressive drugs are associated with rejection in renal transplant patients. The aim of this study was to evaluate some SNPs located in six genes: interleukin-10 (IL-10), tumor necrosis factor (TNF), adenosine triphosphate-binding cassette sub-family B member 1 (ABCB1), uridine diphosphate glucuronosyltransferase family 1 member A9 (UGT1A9), inosine monophosphate dehydrogenase 1 (IMPDH1) and IMPDH2. Methods We enrolled cases with at least one AR after KT and two groups of controls: patients without any AR after KT and healthy blood donors. Genetic analysis on DNA was performed. The heterozygosity (HET) was determined and the Hardy-Weinberg equilibrium (HWE) test was performed for each SNP. The sample size was calculated using the QUANTO program and the genetic associations were calculated using the SAS program (SAS Institute Inc., Cary, NC, USA). Results In our previous preliminary study (sample size was not reached for cases), the results showed that patients with the C allele in the SNP rs1045642 and the A allele in the SNP rs2032582 of the ABCB1 gene had more frequent AR. In contrast, with the achievement of sample size, the trend of the previous data was not confirmed. Conclusions Our study highlights a fundamental aspect of scientific research that is generally presumed, i.e. the sample size of groups enrolled for a scientific study. We believe that our study will make a significant contribution to the scientific community in the discussion of the importance of the analysis and the achievement of sample size to evaluate the associations between SNPs and the studied event.

Evolution of Automated Peritoneal Dialysis Machines.

Peritoneal dialysis (PD) has undergone several improvements over the years. Among the numerous advances, we may recall the improvement in the quality of fluids, safety of catheters and connections, knowledge of the peritoneal membrane in the process of mass transfer separation typical of PD. In parallel with these achievements, PD techniques have also displayed significant improvements mainly due to the evolution of machines and cyclers. Originally, bottles or containers were used to deliver and drain fluid to and from the peritoneal cavity by gravity using manual techniques. Subsequently, the development of semiautomatic or automatic machines have permitted to deliver an adequate treatment during night-time without the need of patient or care giver intervention. These advances solved the problem of treatment delivery, but other aspects including complications and adherence to prescription could only be managed using magnetic cards containing data from different treatments and brought by the patient at the following routinely planned hospital consultation. Today these limitations have been overcome by the new cycler "HOMECHOICE CLARIA" equipped with SHARESOURCE software featuring a bidirectional communication protocol that allows a full remote patient management (RPM). RPM has demonstrated significant advantages including higher technique survival, reduced rate of complications, and reduced costs in patients undergoing long-term PD.

Erythema nodosum: etiological factors and relapses in a retrospective cohort study.

Erythema nodosum (EN) is a septal panniculitis which may be associated with a wide variety of factors and disorders. In some patients it is recurrent, but few studies have considered recurrent EN. Our aim was to describe the causes of and diseases associated with EN and relapsing EN. Patients diagnosed with EN from 1997 to 2007 were included. EN was defined as post-infective, based on temporal, clinical, laboratory and microbiological criteria. Diagnosis of drug-induced EN was based on a temporal correlation, on the relapse of EN after drug re-introduction and on the absence of relapsing EN with a continuous treatment with the imputed drug. When the above criteria were excluded and EN was not associated with an underlying systemic disease or pregnancy, it was considered idiopathic.124 patients (mean age 39.5 years; median 37 years; range 4-90 years) were visited and re-evaluated after one to ten years (mean ± SD follow up time 5 ± 4 years). In 73 (58.8%) patients an aetiology of the first manifestation of EN was attributed to infections (25.8% of the total number; 32% of those with an attributed aetiology), drugs (mostly sex hormones; 15.3%; 26%), systemic diseases (11.2%; 19.2%) and pregnancy (6.5%; 10.9%). EN relapsed in 33 (26.6%) patients and was mostly attributed to infections and drugs. Factors responsible for the first manifestation of EN frequently differed from those causing relapses in the same patients, with the exception of drug-induced EN. We conclude that drug-induced EN can recur after re-exposure to the same drug, and the recurrence can be predicted.