Body Mass Index Thresholds and the Use of Bariatric Surgery in the Field of Kidney Transplantation in Germany

Background

Obesity in the recipient is linked to inferior transplant outcome. Consequently, access to kidney transplantation (KT) is often restricted by body mass index (BMI) thresholds. Bariatric surgery (BS) has been established as a superior treatment for obesity compared to conservative measures, but it is unclear whether it is beneficial for patients on the waiting list.

Methods

A national survey consisting of 16 questions was sent to all heads of German KT centers. Current situation of KT candidates with obesity and the status of BS were queried.

Results

Center response rate was 100%. Obesity in KT candidates was considered an important issue (96.1%; n?=?49/51) and 68.6% (n?=?35/51) of departments responded to use absolute BMI thresholds for KT waiting list access with?≥?35 kg/m² (45.1%; n?=?23/51) as the most common threshold. BS was considered an appropriate weight loss therapy (92.2%; n?=?47/51), in particular before KT (88.2%; n?=?45/51). Sleeve gastrectomy was the most favored procedure (77.1%; n?=?37/51). Twenty-one (41.2%) departments responded to evaluate KT candidates with obesity by default but only 11 (21.6%) had experience with?≥?n?=?5 transplants after BS. Concerns against BS were malabsorption of immunosuppressive therapy (39.2%; n?=?20/51), perioperative morbidity (17.6%; n?=?9/51), and malnutrition (13.7%; n?=?7/51).

Conclusions

Obesity is potentially limiting access for KT. Despite commonly used BMI limits, only few German centers consider BS for obesity treatment in KT candidates by default. A national multicenter study is desired by nearly all heads of German transplant centers to prospectively assess the potentials, risks, and safety of BS in KT waitlisted patients.

Graphical abstract

     

Multiple archaeal groups mediate methane oxidation in anoxic cold seep sediments

No microorganism capable of anaerobic growth on methane as the sole carbon source has yet been cultivated. Consequently, information about these microbes has been inferred from geochemical and microbiological observations of field samples. Stable isotope analysis of lipid biomarkers and rRNA gene surveys have implicated specific microbes in the anaerobic oxidation of methane (AOM). Here we use combined fluorescent in situ hybridization and secondary ion mass spectrometry analyses, to identify anaerobic methanotrophs in marine methane-seep sediments. The results provide direct evidence for the involvement of at least two distinct archaeal groups (ANME-1 and ANME-2) in AOM at methane seeps. Although both archaeal groups often occurred in direct physical association with bacteria, they also were observed as monospecific aggregations and as single cells. The ANME-1 archaeal group more frequently existed in monospecific aggregations or as single filaments, apparently without a bacterial partner. Bacteria associated with both archaeal groups included, but were not limited to, close relatives of Desulfosarcina species. Isotopic analyses suggest that monospecific archaeal cells and cell aggregates were active in anaerobic methanotrophy, as were multispecies consortia. In total, the data indicate that the microbial species and biotic interactions mediating anaerobic methanotrophy are diverse and complex. The data also clearly show that highly structured ANME-2/Desulfosarcina consortia are not the sole entities responsible for AOM at marine methane seeps. Other microbial groups, including ANME-1 archaea, are capable of anaerobic methane consumption either as single cells, in monospecific aggregates, or in multispecies consortia.     

DAOA/G72 predicts the progression of prodromal syndromes to first episode psychosis

The genetic factors determining the progression of prodromal syndromes to first episode schizophrenia have remained enigmatic to date. In a unique prospective multicentre trial, we assessed whether variants at the d-amino acid oxidase activator (DAOA)/G72 locus influence progression to psychosis. Young subjects with a prodromal syndrome were observed prospectively for up to 2 years to assess the incidence of progression to schizophrenia or first episode psychosis. Of the 82 probands with a prodromal syndrome, 21 probands experienced progression to psychosis within the observation period. Assessment of nine common variants in the DAOA/G72 locus yielded two variants with the predictive value for symptom progression: all four probands with the rs1341402 CC genotype developed psychosis compared with 17 out of 78 probands with the TT or CT genotypes (χ² = 12.348; df = 2; p = 0.002). The relative risk for progression to psychosis was significantly increased in the CC genotype: RR = 4.588 (95% CI = 2.175–4.588). Similarly, for rs778294, 50% of probands with the AA genotype, but only 22% of probands with a GG or GA genotype progressed to psychosis (χ² = 7.027; df = 2; p = 0.030). Moreover, haplotype analysis revealed a susceptibility haplotype for progression to psychosis. This is one of the first studies to identify a specific genetic factor for the progression of prodromal syndromes to schizophrenia, and further underscores the importance of the DAOA/G72 gene for schizophrenia.     

Sensorimotor gating of schizophrenia patients depends on Catechol O-methyltransferase Val158Met polymorphism

It has been recently shown that Catechol O-methyltransferase (COMT) Val(158)Met polymorphism strongly influences prepulse inhibition (PPI) of the acoustic startle response (ASR) in healthy human volunteers. Given that schizophrenia patients exhibit impairment in PPI and that COMT is a putative susceptibility gene for schizophrenia, we investigated the impact of the COMT Val(158)Met polymorphisms on PPI in schizophrenic inpatients. We analyzed COMT Val(158)Met polymorphisms and assessed startle reactivity, habituation, and PPI of ASR in 68 Caucasian schizophrenia inpatients. Clinical symptoms were measured with the Positive and Negative Syndrome Scale (PANSS). Patients carrying the Val(158)Met Met/Met allele showed elevated PPI levels whereas startle reactivity and habituation did not differ from the other two genotypes. These preliminary results imply that PPI is influenced by COMT Val(158)Met genotype in schizophrenia as well. In concert with other findings, our data suggest that PPI is a polygenic trait.     

Depression during an acute episode of schizophrenia or schizophreniform disorder and its impact on treatment response

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