Kidney failure secondary to hereditary xanthinuria due to a homozygous deletion of the XDH gene, in the absence of overt kidney stone disease

Hereditary xanthinuria (HXAN) is a rare metabolic disorder that results from mutations in either the xanthine dehydrogenase (XDH) or the molybdenum cofactor sulfurase genes (MOCOS), respectively defining HXAN type I and type II. Hypouricemia, hypouricosuria, and abnormally high plasma and urine levels of xanthine, causing susceptibility to xanthine nephrolithiasis and deposition of xanthine crystals in tissues, are the metabolic hallmarks of HXAN. Several pathogenic variants in the XDH gene have so far been identified in patients with HXAN type I, but the clinical phenotype associated with the whole deletion of the human XDH gene is unknown. Herein, we report the case of a woman diagnosed with HXAN, whose molecular genetic testing revealed a homozygous microdeletion involving the XDH gene. Distinctive features of her medical history were the diagnosis of arterial hypertension and microalbuminuria at 22 years of age; a single pregnancy, at the age of 25, complicated by proteinuria and transient kidney function deterioration in the third trimester; unexplained severe hypouricaemia incidentally discovered during pregnancy; inability to breastfeed her newborn daughter due to primary agalactia; chronic kidney disease (CKD) stage 3 diagnosed at age 35; and progression to end-stage kidney disease over the next 12 years. Protocol non-invasive laboratory and imaging investigation was not informative as to the cause of CKD. This is the first description of the clinical phenotype associated with a natural knockout of the human XDH gene. Despite the lack of kidney histopathology data, the striking similarities with the phenotypes exhibited by comparable murine models validates the latter as useful sources of mechanistic insights for the pathogenesis of the human disease, supporting the hypothesis that the absence of xanthine dehydrogenase activity might represent a susceptibility factor for chronic tubulointerstitial nephritis, even in patients without kidney stones.

The complexity of decisions in genetics: annotation of three novel variants in the PKD1 and PKD2 genes

As nephrology practice is evolving towards precision medicine, and genetic tests are becoming widely available, basic genetic literacy is increasingly required for clinical nephrologists. Yet, decisions based on results of genetic tests are seldom straightforward. We report a 37-year-old woman with autosomal dominant polycystic kidney disease (ADPKD) who was referred for medically assisted reproduction with monogenic preimplantation genetic testing (PGT-M). The PKD1 and PKD2 genes were screened for pathogenic variants. Sequencing analysis revealed the presence of three novel missense single nucleotide variants, two in the PKD1 gene - c.349T>G, p.(Leu117Val) and c.1736C>T, p.(Pro579Leu); and the third in the PKD2 gene - c.1124A>G, p.(Asn375Ser). Bioinformatic predictions of the functional effects of those three missense variants were inconsistent across different software tools. The family segregation analysis, which was mandatory to identify the relevant variant(s) for PGT-M, strongly supported that the disease-causing variant was PKD1 c.349T>G p.(Leu117Val), while the other two were non-pathogenic or, at most, phenotypic modulators. Proving the pathogenicity of novel variants is often complex, but is critical to guide genetic counselling and screening, particularly when discussing reproductive alternatives for primary prevention in the progeny of at-risk couples. The family reported herein illustrates those challenges in the setting of ADPKD, and the invaluable importance of a detailed family history and segregation analysis for proper clinical annotation of novel variants. Basic genetic knowledge and proper clinical annotation of novel allelic variants in genes associated with hereditary kidney disorders are increasingly necessary for the contemporary practice of clinical nephrology.

Renal manifestations in adults with mitochondrial disease from the mtDNA m.3243A>G pathogenic variant

Mitochondrial diseases are a phenotype and genotype heterogeneous group of disorders that typically have a multisystemic involvement. The m.3243A>G pathogenic variant is the most frequent mitochondrial DNA defect, and it causes several different clinical syndromes, such as mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS), and the maternally inherited diabetes and deafness (MIDD) syndromes. Not frequently reported, renal involvement in these diseases is probably underestimated, yet it increases morbidity. It generally manifests as subnephrotic proteinuria and progressive deterioration of kidney function. Adult presentation of mitochondrial diseases is hard to recognize, especially in oligosymptomatic patients or those with exclusive kidney involvement. However, suspicion should always arise when family history, particularly on the maternal side, and multisystemic symptoms, most often of the central nervous system and skeletal muscles, are present. In this review we discuss the clinical diagnosis and approach of patients with renal manifestations in the context of the mtDNA m.3243A>G pathogenic variant.

Diagnosis and referral of patients with AL amyloidosis in Portugal: results from a Delphi panel

Light chain amyloidosis (AL) is a complex disorder defined by the extracellular deposition of insoluble amyloid fibrils formed by intact or fragmented immunoglobulin light chains, leading to cell dysfunction, rapid organ deterioration, and, ultimately, death. Although the clinical presentation of AL is directly connected to organ involvement, signs and symptoms of AL are frequently nonspecific, misinterpreted, and late recognized. Thus, an early diagnosis combined with effective therapies to cease disease progression and rescue organ function is essential. The aim of this study was to assess the knowledge and characterize the current clinical practice regarding AL diagnosis and referral among Portuguese physicians. A Delphi-like panel (one round only) with a group of national experts from different medical specialties (cardiology, hematology, internal medicine, nephrology, and neurology) was carried out online, in which 30 statements were classified using a 4-point Likert scale. For each statement, the consensus level was set at 70% for "fully agree/disagree" and the majority level was defined as >70% in agreement or disagreement. Although the results suggest the existence of adequate general knowledge of AL amyloidosis, they also disclosed the necessity to raise awareness for this disease. Overall, this Delphi panel revealed a high lack of consensus regarding the diagnosis and early management of patients with AL among different specialties despite the qualified majority obtained in 26 statements. An optimized strategy for AL early diagnosis, transversal to several medical fields, is urgently needed. Moreover, referral centers with access to diagnostic technology and a network of diverse specialties should be established to foster an early diagnosis and better disease approach to boost the possibility of a better outcome for patients with AL.

Development and Validation of a Self-Administered Questionnaire Measuring Essential Knowledge in Patients With Axial Spondyloarthritis

OBJECTIVE

To develop and validate a patient knowledge questionnaire regarding axial spondyloarthritis (axSpA).

METHODS

Knowledge considered essential for patients with axSpA was identified through Delphi rounds among rheumatologists, healthcare professionals (HCPs), and patients, then reformulated to develop the knowledge questionnaire. Cross-sectional validation was performed in 14 rheumatology departments to assess internal validity (Kuder-Richardson coefficient), external validity, acceptability, reproducibility (Lin concordance correlation coefficient), and sensitivity to change (knowledge score before vs after patient education sessions and effect size).

RESULTS

The Spondyloarthritis Knowledge Questionnaire (SPAKE) is a self-administered 42-item questionnaire with a 32-item short form, both scored 0 to 100, assessing knowledge of disease, comorbidities, pharmacological treatments, nonpharmacological treatments, self-care, and adaptive skills. In the validation study (130 patients; 67 [51.5%] male, mean age 43.5 [SD 12.9] yrs), the mean (SD) score of the long-form questionnaire was 71.6 (15.4), with higher scores (better knowledge) in nonpharmacological treatments and adaptive skills and lower scores in cardiovascular comorbidity and pharmacological treatments. Acceptability was good, with no missing data; the internal validity coefficient was 0.85. Reproducibility was good (0.81, 95% CI 0.72-0.89). SPAKE showed good sensitivity to change; scores were 69.2 (15.3) then 82.7 (14.0) after patient education sessions (Hedges effect size = 0.92, 95% CI 0.52-1.31).

CONCLUSION

SPAKE is a knowledge questionnaire for patients with axSpA, developed with the involvement of HCPs and patients and reflecting current recommendations for the management of axSpA. SPAKE will be useful in assessing knowledge acquisition and self-management strategies in routine care and research.

Increased platelet activation and platelet-inflammasome engagement during chikungunya infection

Chikungunya fever is a viral disease transmitted by mosquitoes of the genus Aedes. The infection is usually symptomatic and most common symptoms are fever accompanied by joint pain and swelling. In most cases symptoms subside within a week. However, severe prolonged and disabling joint pain, that may persist for several months, even years, are reported. Although the pathogenesis of Chikungunya infection is not fully understood, the evolution to severe disease seems to be associated with the activation of immune mechanisms and the action of inflammatory mediators. Platelets are recognized as inflammatory cells with fundamental activities in the immune response, maintenance of vascular stability and pathogenicity of several inflammatory and infectious diseases. Although the involvement of platelets in the pathogenesis of viral diseases has gained attention in recent years, their activation in Chikungunya has not been explored. The aim of this study was to analyze platelet activation and the possible role of platelets in the amplification of the inflammatory response during Chikungunya infection. We prospectively included 132 patients attended at the Quinta D’Or hospital and 25 healthy volunteers during the 2016 epidemic in Rio de Janeiro, Brazil. We observed increased expression of CD62P on the surface of platelets, as well as increased plasma levels of CD62P and platelet-derived inflammatory mediators indicating that the Chikungunya infection leads to platelet activation. In addition, platelets from chikungunya patients exhibit increased expression of NLRP3, caspase 4, and cleaved IL-1β, suggestive of platelet-inflammasome engagement during chikungunya infection. In vitro experiments confirmed that the Chikungunya virus directly activates platelets. Moreover, we observed that platelet activation and soluble p-selectin at the onset of symptoms were associated with development of chronic forms of the disease. Collectively, our data suggest platelet involvement in the immune processes and inflammatory amplification triggered by the infection.

Lessons from Four Decades of Systemic Amyloidosis with Renal Involvement

BACKGROUND

Apart from ATTR amyloidosis, the epidemiology and outcomes of the most common subtypes of systemic amyloidosis in Portugal remain primarily unknown.

METHODS

This retrospective cohort study evaluated patients with renal biopsy-proven amyloidosis, diagnosed from January 1978 to December 2019. Follow-up started at kidney disease presentation and ended at death or August 2020. Clinical presentation, survival, and prognostic factors were analysed.

RESULTS

Of 123 patients with amyloid nephropathy, 111 had definite amyloid typing and were analysed. AA amyloidosis was the most frequent type (56.1%) and was related mainly to chronic infection (47.8%) and chronic inflammatory arthritis (29.0%). AL amyloidosis was present in 25.2% of patients and hereditary forms in 6.5% (4.1% AFibE526V, 2.4% ATTRV30M). During follow-up, 73.9% of AA and 54.8% of AL patients progressed to end-stage renal disease, and 79.7% of AA and 77.4% of AL died; median overall survival was 66.0 (95% CI, 33.0-99.0) and 18.0 (95% CI, 9.3-26.7) months (p = 0.025), respectively. There were no significant differences in renal outcome and survival on dialysis between these two types. In multivariate analysis, cardiac involvement at presentation (HR 6.26 [95% CI, 2.89-13.56]) and estimated glomerular filtration rate <30 mL/min/1.73 m2 (HR 2.05 [95% CI, 1.06-3.99]) independently influenced AA and AL amyloidosis survival. Cardiac involvement at presentation was an independent predictor of death (HR 9.65 [95% CI, 2.91-31.95]) and early mortality in AL amyloidosis.

CONCLUSIONS

In Portugal, AA amyloidosis and related chronic infections are still relevant. Regarding AL amyloidosis, the low incidence and advanced disease at presentation result from missed and erroneous diagnoses, leading to delayed referrals and poor outcomes in these patients.

Spleen-Restricted Posttransplant Lymphoproliferative Disorder in the First Year After Kidney Transplant - A Case Report

Posttransplant lymphoproliferative disorders (PTLDs) are a feared complication after transplant. They are mostly of B cell origin and are frequently Epstein-Barr virus (EBV)-positive, particularly in early onset PTLD. Later on, non-B and EBV-negative PTLD are increasingly reported. EBV seronegative receptors (particularly when paired with an EBV seropositive donor) together with the net degree of immunosuppression-a concept often difficult to quantify-are the most consistently described risk factors for the development of PTLD. Conversely, its association with a particular immunosuppressive agent or other virus, namely cytomegalovirus (CMV) infection or disease, has been inconsistently reported. We present a challenging case where an EBV negative monomorphic peripheric T-cell lymphoma was diagnosed in the first year after kidney transplant in a patient with a recent history of CMV disease from a resistant strain.

Severe L-asparaginase-induced Hypertriglyceridaemia Treated with Plasmapheresis

L-asparaginase is used for the treatment of acute lymphoblastic leukaemia. Hypertriglyceridaemia is a side effect and associated with potentially fatal complications, including acute pancreatitis. Plasmapheresis may have a role in treatment when triglycerides are >2000 mg/dl. We report the case of a 39-year-old woman treated with L-asparaginase for acute lymphoblastic leukaemia, who developed severe hypertriglyceridaemia (6560 mg/dl) and acute pancreatitis. Intravenous insulin infusion was started, along with fenofibrate and atorvastatin administration, and platelet transfusion. Plasmapheresis was carried out leading to a frank decline in serum triglyceride levels (366 mg/dl), a decrease in pancreatic enzymes and clinical improvement. The diagnosis of pancreatitis secondary to L-asparaginase should lead to immediate drug withdrawal, and plasmapheresis should be considered when serum triglyceride values exceed 2000 mg/dl. In our case, there was a 95% triglyceride removal rate. This response illustrates the strong effectiveness of early treatment with plasmapheresis in severe and symptomatic hypertriglyceridaemia associated with L-asparaginase.

LEARNING POINTS

Pancreatitis following L-asparaginase-induced hypertriglyceridaemia is a severe and potentially reversible condition in both adults and children treated for acute lymphoblastic leukaemia.Early plasmapheresis is more effective to rapidly decrease serum triglycerides.

Viral Clearance and Serological Response to SARS-CoV-2 in Kidney Transplant Recipients

Objectives

Knowledge about the impact of coronavirus disease 2019 (COVID-19) on kidney transplant recipients (KTRs) concerning viral shedding and humoral immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is limited. The aim of this study is to analyze viral dynamics and the antibody response to SARS-CoV-2 in KTRs with COVID-19 and study their association with clinical data.

Materials and methods

Consecutive KTRs diagnosed with COVID-19 at our center were evaluated for clinical presentation and outcome; duration of viral shedding and viral burden by reverse transcription-polymerase chain reaction assay cycle threshold; and magnitude of seroconversion to SARS-CoV-2.

Results

Six KTRs identified with COVID-19 were hospitalized. Presenting symptoms were similar to those in the general population. Four patients had severe disease and, of these, 2 required mechanical ventilation, 4 had acute kidney injury, and 3 had secondary bacterial infections. Immunosuppression was reduced in all patients. Five patients were treated with hydroxychloroquine. No patient required dialysis or died. Patients with severe disease had a longer duration of viral shedding, which lasted more than 40 days, and had IgG antibodies against SARS-CoV-2, which were detected from 3 weeks to as long as 10 weeks after symptom onset. In patients with less severe disease no IgG antibodies where detected between 9 and 14 weeks after symptom onset.

Conclusions

In our series, KTRs with severe COVID-19 had prolonged viral shedding and a stronger humoral immune response to SARS-CoV-2. These preliminary data need to be confirmed with further studies and over a longer period of time.

Patient with McCune albright syndrome: Case report and 10 Years of follow-up imaging examination

The McCune Albright syndrome (MAS) is a rare, multi-system disease composed of the triad of polyostotic fibrous dysplasia of bone (PFDB), café-au-lait skin hyperpigmentation, and endocrine disorders. The diagnosis involves clinical, biochemical and imaging findings, with dentistry playing an important role in MAS, since many patients present DFPO in the craniofacial bones, including the maxilla and mandible, and in view of their dental needs, the correct management of these patients is not only an essential but important area to be investigated. This report presents a case of a patient with McCune Albright Syndrome, the behavior of the disease over a period of 10 years and how imaging exams such as scintigraphy and tomography were important for planning the dental treatment of this patient, since they are fundamental allies for identification and evaluation of the progression and/or stability of the disease. Key words:Craniofacial fibrous dysplasia, cone-beam computed tomography, scintigraphy, imaging diagnosis.

Cardiac Amyloidosis Associated with Apolipoprotein A-IV Deposition Diagnosed by Mass Spectrometry-Based Proteomic Analysis

Amyloidosis is a group of disorders characterised by the accumulation of extracellular deposits of insoluble protein aggregates. Clinical management depends on the accurate identification of the amyloid precursor and underlying cause. We describe a rare case of apolipoprotein A-IV cardiac amyloidosis, the diagnosis of which required mass spectrometry-based proteomic analysis.

Reactivation of Hepatitis B virus in kidney transplant recipients with previous clinically resolved infection: A single-center experience

BACKGROUND

Hepatitis B virus (HBV) reactivation in kidney transplant recipients (KTR) involves important morbidity and mortality. Despite being more common in patients who are HBsAg-positive, it may occur in patients with clinically resolved infection (HBsAg-negative and anti-HBc-positive), in whom the presence of the protective anti-HB antibody is thought to decrease the risk of reactivation. Data regarding reactivation rates in this population are scarce.

OBJECTIVE

To retrospectively evaluate the risk of HBV reactivation in KTR with previously resolved infection.

MATERIAL AND METHODS

Retrospective cohort study including patients who underwent a kidney transplant between January 1994 and December 2014 with resolved HBV infection at the time of transplantation (anti-HBc seropositivity without detectable HBsAg, with or without anti-HB-positive antibodies and normal liver enzymes).

RESULTS

Out of 966 patients, 95 patients with evidence of resolved HBV infection were analyzed, of which 86 had a titer of anti-HBs >10mIU/ml. Mean follow-up time was 93 months; 12 patients had lost anti-HBs. Two patients showed evidence of reactivation. Risk factors associated with loss of anti-HBs were elderly age (>60) and occurrence of acute graft rejection (p<0.05).

CONCLUSION

The risk of HBV reactivation in KTR with previously resolved infection is not negligible at 2%. Elderly age and acute rejection were associated with loss of anti-HBs, and these patients may benefit from closer monitoring of HBV DNA levels. Routine serology and/or HBV viral load monitoring in HBsAg-negative, anti-HBc-positive patients is recommended and should be emphasized in these patients.

MACVIA-LR (Fighting Chronic Diseases for Active and Healthy Ageing in Languedoc-Roussillon): A Success Story of the European Innovation Partnership on Active and Healthy Ageing

The Région Languedoc Roussillon is the umbrella organisation for an interconnected and integrated project on active and healthy ageing (AHA). It covers the 3 pillars of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA): (A) Prevention and health promotion, (B) Care and cure, (C) and (D) Active and independent living of elderly people. All sub-activities (poly-pharmacy, falls prevention initiative, prevention of frailty, chronic respiratory diseases, chronic diseases with multimorbidities, chronic infectious diseases, active and independent living and disability) have been included in MACVIA-LR which has a strong political commitment and involves all stakeholders (public, private, patients, policy makers) including CARSAT-LR and the Eurobiomed cluster. It is a Reference Site of the EIP on AHA. The framework of MACVIA-LR has the vision that the prevention and management of chronic diseases is essential for the promotion of AHA and for the reduction of handicap. The main objectives of MACVIA-LR are: (i) to develop innovative solutions for a network of Living labs in order to reduce avoidable hospitalisations and loss of autonomy while improving quality of life, (ii) to disseminate the innovation. The three years of MACVIA-LR activities are reported in this paper.

Late Allograft Renal Vein Thrombosis Treated With Anticoagulation Alone: A Case Report

BACKGROUND

Allograft renal vein thrombosis is a rare complication of kidney transplantation. Most cases occur in the first 2 weeks after transplantation, but there are cases described many years after the transplant surgery. Allograft loss is the usual outcome.

METHODS

We present a case of a renal transplant recipient with allograft renal vein thrombosis associated with deep venous thrombosis of a lower limb, 9 years after transplantation. He was successfully treated with anticoagulation alone, with recovery of allograft function.

RESULTS

The patient was given unfractioned heparin and elastic compression stockings. Five days later, the patient recovered diuresis and hemodialysis treatment was discontinued. Doppler ultrasound was done and revealed partial re-permeabilization of allograft renal vein, with maximal velocity of 15 cm/s. After 30 months of follow-up, the patient was maintained on oral anticoagulation with warfarin, and no thromboembolic or hemorrhagic events were documented. The patient's serum creatinine was stable, between 1.6 and 1.8 mg/dL.

CONCLUSIONS

Our patient demonstrated that anticoagulation alone and dialytic support might be able to promote total recovery of allograft function after renal vein thrombosis.

Unrecognized Fibrinogen A α-Chain Amyloidosis: Results From Targeted Genetic Testing

BACKGROUND

Fibrinogen A α-chain (AFib) amyloidosis results from autosomal-dominant mutations in the gene encoding AFib (FGA). Patients with this disorder typically present with proteinuria. Isolated cases of AFib amyloidosis, carrying the FGA p.Glu545Val variant, were identified in the district of Braga, in northwest Portugal. This observation led us to hypothesize that this disorder might be an unrecognized cause of kidney disease in that region and prompted us to carry out targeted genetic testing for the p.Glu545Val variant in the local hemodialysis population and family members of identified cases.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

3 groups of participants: (1) kidney biopsy registry, n=4; (2) hemodialysis facility, n=122 of 267 patients; and (3) genetically at-risk individuals; n=69 of 167 family members.

OUTCOMES

Kidney disease, kidney disease progression, and survival.

RESULTS

The p.Glu545Val variant was identified in all 4 patients of the biopsy registry, 12 of 122 (9.8%) hemodialysis patients tested, and 34 of 69 (49%) relatives tested. These 50 cases belonged to 13 unrelated families with kidney disease or amyloidosis identified in 61% of probands. 35 individuals presented with hypertension at a mean of 51.0±10.4 years. Of these, 30 developed kidney disease at a mean of 56.7±12.0 years, and 21 initiated dialysis therapy at a mean of 61.4±11.3 years. Heart, liver, spleen, colon, and ileum were involved along the progression of the disease. Kidney disease was formerly attributed to hypertension in 25% of patients with AFib amyloidosis undergoing hemodialysis.

LIMITATIONS

Retrospective data collection for patients with amyloidosis previously diagnosed.

CONCLUSIONS

AFib amyloidosis appears to be an under-recognized disorder in Braga, Portugal, where we found a high frequency of the FGA p.Glu545Val variant. Due to the nonspecific nature of its major clinical features, the diagnosis of AFib amyloidosis should have a high index of suspicion, particularly in populations in which hypertension is prevalent.

Endovanilloid control of pain modulation by the rostroventromedial medulla in an animal model of diabetic neuropathy

The involvement of transient receptor vanilloid type-1 (TRPV1) channels in pain modulation by the brain remains understudied. The rostroventromedial medulla (RVM) plays a key role in conveying to the spinal cord pain modulatory influences triggered in higher brain centres, with co-existence of inhibitory (antinociceptive) and facilitatory (pronociceptive) effects. In spite of some reports of TRPV1 expression in the RVM, it remains unknown if endovanilloid signalling plays a direct role in local pain modulation. Here we used a model of diabetic neuropathy, the streptozotocin (STZ)-diabetic rat, to study the role of endovanilloid signalling in RVM-mediated pain modulation during chronic pain. Four weeks after diabetes induction, the levels of TRPV1 mRNA and fatty acid amide hydrolase (FAAH), a crucial enzyme for endovanilloid catabolism, in the RVM of STZ-diabetic rats were higher than control. The RVM of STZ-diabetic rats presented decreased levels of several TRPV1 endogenous ligands, namely anandamide (AEA), palmitoylethanolamide (PEA) and oleoylethanolamide (OEA). Administration of capsaicin (a TRPV1 agonist) into the RVM decreased nociceptive behavioural responses in the inflammatory phase of the formalin test (phase 2). These findings suggest that diabetic neuropathy induces plastic changes of RVM endovanilloid signalling, indicating that TRPV1 may be a putative target for pain modulation in this chronic pain condition.

Inhibition of spinal 5-HT3R reverted diabetes-induced mechanical hypersensitivity in a GABAAR-mediated neurotransmission-dependent manner

Spinal 5-HT3 receptor (5-HT3R) has been implicated in chronic pain development. The extent to which 5-HT3R contributes to spinal sensitization and diabetic neuropathic pain (DNP) remains elusive and the mechanisms subserving the effects of 5-HT3R activation on spinal pain processing during chronic pain are still unclear. In this study, we evaluated the contribution of spinal 5-HT3R to pain facilitation and spinal sensitization during DNP, exploiting the role of GABAAR-mediated neurotransmission and glial activation in the effects elicited by intrathecal administration of a 5-HT3R antagonist. Mechanical nociception was evaluated by paw pressure test in streptozotocin (STZ)-diabetic and control rats after intrathecal (i.t.) administration of a 5-HT3R antagonist (Y25130). The spinal activation of extracellular signal-regulated kinases (ERKs) pathway and the expression of 5-HT3R, glial fibrillary acidic protein (GFAP; marker of astroglia activation) and ionized calcium binding adaptor molecule 1 (IBA-1; marker of microglia activation) were evaluated at the peak maximum effect of Y25130. The involvement of GABAAR-mediated neurotransmission in the behavioral pain effect of Y25130, was assessed in STZ-diabetic animals receiving i.t. administrations of muscimol (GABAAR agonist). Intrathecal administration of Y25130 reverted mechanical hyperalgesia and decreased the activation of ERKs in STZ-diabetic rats, while no effects were observed in control animals. The spinal activation of GABAAR by i.t. administration of muscimol abolished Y25130-driven antinociception. The expression of IBA-1, GFAP and 5-HT3R was unaltered by treatment. These findings point to a GABA-mediated pronociceptive role of spinal 5-HT3R during DNP.

Is there a relationship between intraoperative hemodynamic instability and calcineurin inhibitor-related toxicity, early after liver transplantation? A single-center observational study

This study evaluated the relationship between intraoperative hemodynamic instability (IOHI) and the development of calcineurin inhibitor (CNI) toxicity in the early postoperative period after liver transplantation (LT). Eighty-two patients were enrolled during a 1-year period and a 3-month follow-up. IOHI, requiring continuous infusion of vasopressors, was observed in 31 patients (38%, group 1; control group 2, n = 51). Acute kidney injury (AKI) developed in 28 patients (52% in group 1 vs 24% in group 2, P = .02), and CNI-related neurotoxicity (CNI-NT) in 26 (48% in group 1 vs 22% in group 2, P = .03). Group 1 patients received mainly deceased donor grafts (87% vs 57% in group 2, P < .001). An independent association between IOHI and CNI-NT (P = .029) and AKI (P = .016) was observed. The receiver-operator characteristic curve revealed an area under the curve of 0.63 for IHI (sensitivity 56%; specificity 75%) and 0.65 for AKI (sensitivity 56%; specificity 70.2%). In conclusion, patients undergoing LT with IOHI may be more prone to developing CNI-NT and AKI in the early postoperative period.

Renal transplantation in human immunodeficiency virus-positive patients: a report of four cases

INTRODUCTION

Renal transplantation (RT) in patients infected with human immunodeficiency virus (HIV) has significantly improved under the advent of combined antiretroviral therapy (cART). The authors describe their experience in RT in patients with HIV from September 2010 to June 2013.

CASES REPORT

Four patients underwent transplantation (3 with HIV-1 and 1 with HIV-2), three patients were male, and one was black. None were coinfected with hepatitis B virus (HBV) or hepatitis C virus (HCV). Etiology of kidney disease was HIV-associated nephropathy (2 patients), immunoglobulin (Ig)A nephropathy, and unknown. Average age at RT was 51 (range, 41-63) years. No patient was of high immunologic risk. Immunosuppression consisted of basiliximab for induction and prednisolone, tacrolimus (TAC), and mycophenolate mofetil for maintenance. TAC levels varied considerably in the early days (8.5-46 ng/mL), requiring major adjustments in TAC dose. Only the HIV-2 patient had delayed graft function. The follow-up of patients with HIV-1 was 37, 19, and 16 months, and 3 months for the HIV-2 patient. CD4+ T cells decreased in the early days after transplantation with subsequent improvement, along with persistent virological suppression. In the HIV-1 group there were no major infectious, cardiovascular, or neoplastic complications. Nevertheless, the HIV-2 patient died 3 months after RT due to H1N1 pneumonia complicated by pulmonary aspergillosis. Average estimated (CKD- EPI) glomerular filtration rate (eGFR) at 6 months was 85.6 mL/min/1.73 m(2).

CONCLUSION

Besides the difficulty in adjusting calcineurin inhibitors levels due to its interaction with antiretroviral therapy, namely with protease inhibitors, no patient had acute rejection. Furthermore, all patients presented an excellent control of viro-immunologic parameters. At the last follow-up neither cardiovascular events nor neoplastic complications were observed. Our results highlight the favorable outcome of RT in HIV-1-infected patients. The HIV-2 patient died due to severe infection, and the clinical management and potential benefit of RT in HIV-2-infected patients needs further study.

Can the dopaminergic-related effects of general anesthetics be linked to mechanisms involved in drug abuse and addiction?

BACKGROUND

General anesthetics (GA) are well known for the ability to induce a state of reversible loss of consciousness and unresponsiveness to painful stimuli. However, evidence from animal models and clinical studies show that GA exposure may induce behavioral changes beyond acute effects. Most research and concerns are focused on changes in cognition and memory.

METHODS

We will look at effects of GA on behavior that is mediated by the dopaminergic system.

RESULTS

Pharmacological resemblance of GA with drugs of abuse, and the complexity and importance of dopaminergic systems in both reward seeking and addictive illnesses make us believe that it deserves an overview about what is already known and what matters to us as healthcare workers and specifically as anesthesiologists.

CONCLUSION

A review of available evidence strongly suggests that there may be a link between the effects of GA on the brain and substance abuse, partly explained by their influence on the dopaminergic system.

Nociceptive spinal cord neurons of laminae I-III exhibit oxidative stress damage during diabetic neuropathy which is prevented by early antioxidant treatment with epigallocatechin-gallate (EGCG)

Spinal cord neurons located in laminae I-III respond to nociceptive stimuli and participate in the transmission of painful information to the brain. In the present study we evaluated if nociceptive laminae I-III neurons are affected by oxidative stress damage in a model of diabetic neuropathic pain (DNP), the streptozotocin-induced diabetic rat (STZ rat). Additionally, we evaluated the effects of a preventive antioxidant treatment with epigallocatechin-gallate (EGCG) in nociceptive neuronal activation and behavioural signs of DNP. Three days after diabetes induction, a treatment protocol of STZ rats with an aqueous solution of EGCG in the drinking water was initiated. Ten weeks after the onset of treatment, the spinal cords were immunoreacted against validated markers of oxidative stress damage (8-hydroxy-2'-deoxyguanosine; 8-OHdG) and of nociceptive neuronal activation (Fos). Mechanical hypersensitivity was assessed before and after EGCG treatment. Untreated STZ rats presented increased levels of 8-OHdG immunoreaction, higher numbers of Fos-immunoreacted neurons and high levels of co-localization of 8-OHdG and Fos in laminae I-III. Treatment with EGCG normalized the increase of the above mentioned parameters and ameliorated mechanical hypersensitivity. The present study shows that nociceptive neurons in spinal cord laminae I-III exhibit oxidative stress damage during diabetic neuropathy, which probably affects ascending pain transmission during DNP. The neurobiological mechanisms and translational perspectives of the beneficial effects of a preventive and sustained EGCG treatment in DNP need to be evaluated in the future.

Collagen type IV-related nephropathies in Portugal: pathogenic COL4A5 mutations and clinical characterization of 22 families

Alport syndrome (AS) is caused by pathogenic mutations in the genes encoding α3, α4 or α5 chains of collagen IV (COL4A3/COL4A4/COL4A5), resulting in hematuria, chronic renal failure (CRF), sensorineural hearing loss (SNHL) and ocular abnormalities. Mutations in the X-linked COL4A5 gene have been identified in 85% of the families (XLAS). In this study, 22 of 60 probands (37%) of unrelated Portuguese families, with clinical diagnosis of AS and no evidence of autosomal inheritance, had pathogenic COL4A5 mutations detected by Sanger sequencing and/or multiplex-ligation probe amplification, of which 12 (57%) are novel. Males had more severe and earlier renal and extrarenal complications, but microscopic hematuria was a constant finding irrespective of gender. Nonsense and splice site mutations, as well as small and large deletions, were associated with younger age of onset of SNHL in males, and with higher risk of CRF and SNHL in females. Pathogenic COL4A3 or COL4A4 mutations were subsequently identified in more than half of the families without a pathogenic mutation in COL4A5. The lower than expected prevalence of XLAS in Portuguese families warrants the use of next-generation sequencing for simultaneous COL4A3/COL4A4/COL4A5 analysis, as first-tier approach to the genetic diagnosis of collagen type IV-related nephropathies.

"Hotheaded": the role OF TRPV1 in brain functions

The TRPV1 (vanilloid 1) channel is best known for its role in sensory transmission in the nociceptive neurons of the peripheral nervous system. Although first studied in the dorsal root ganglia as the receptor for capsaicin, TRPV1 has been recently recognized to have a broader distribution in the central nervous system, where it is likely to constitute an atypical neurotransmission system involved in several functions through modulation of both neuronal and glial activities. The endovanilloid-activated brain TRPV1 channels seem to be involved in somatosensory, motor and visceral functions. Recent studies suggested that TRPV1 channels also account for more complex functions, as addiction, anxiety, mood and cognition/learning. However, more studies are needed before the relevance of TRPV1 in brain activity can be clearly stated. This review highlights the increasing importance of TRPV1 as a regulator of brain function and discusses possible bases for the future development of new therapeutic approaches that by targeting brain TRPV1 receptors might be used for the treatment of several neurological disorders.