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.

Performance of the ACMG-AMP criteria in a large familial renal glucosuria cohort with identified SLC5A2 sequence variants

Familial Renal Glucosuria (FRG) is a co-dominantly inherited trait characterized by orthoglycaemic glucosuria. From 2003 to 2015 we have reported several cohorts validating SLC5A2 (16p11.2), encoding SGLT2 (Na+/glucose cotransporter family member 2), as the gene responsible for FRG. The aim of this work was to validate the variants identified in our extended FRG cohort of published, as well more recent unreported cases, according to the ACMG-AMP 2015 criteria. Forty-six variants were evaluated, including 16 novel alleles first described in this study. All are rare, ultra-rare or absent from population databases and most are missense changes. According to the ACMG-AMP standards, only 74% of the variants were classified as P/LP. The lack of descriptions of unrelated patients with similar variants or failing to test additional affected family members, averted a conclusion for pathogenicity in the alleles that scored VUS, highlighting the importance of both family testing and variant reporting. Finally, the cryo-EM structure of the hSGLT2-MAP17 complex in the empagliflozin-bound state improved the ACMG-AMP pathogenicity score by identifying critical/functional protein domains.

Acute interstitial nephritis due to dolutegravir: The first case reported

Kidney disease is frequent in HIV-patients. We present a case of a 44-year-old woman, with known uncontrolled HIV infection and chronic kidney disease due to HIV-associated nephropathy. After starting dolutegravir, the patient developed eosinophilia and worsening kidney function. A kidney biopsy confirmed the diagnosis of acute interstitial nephritis. Given the time relation with dolutegravir introduction, it was deemed the culprit medication. Dolutegravir was stopped, and corticosteroids were initiated, with moderate improvement in renal function. To our knowledge, this is the first reported case of acute interstitial nephritis to dolutegravir, which should raise awareness of previously undocumented renal effects of antiretroviral therapy.

Urinary Sediment Microscopy and Correlations with Kidney Biopsy: Red Flags Not To Be Missed

BACKGROUND

Urinary sediment is a noninvasive laboratory test that can be performed by an automated analyzer or manually by trained personnel. Manual examination remains the diagnostic standard because it excels at differentiating isomorphic from dysmorphic red blood cells and identifying other urinary particles such as renal tubular epithelial cells (RTECs), lipids, crystals, and the composition of casts. This study aimed to investigate the prevalence of a complete profile of urinary sediment particles and its associations with histologic lesions on kidney biopsy, regardless of diagnosis.

METHODS

This was a single-center, observational retrospective study of 131 patients who had contemporary manual urinary sediment evaluation and kidney biopsy. A comprehensive set of urinary particles and histologic lesions were quantified, and their associations were analyzed.

RESULTS

In our samples, we found an elevated frequency of findings suggestive of proliferative kidney disease and a low frequency of particles evoking urologic damage. The association of histologic lesions and urinary particles was explored with a multivariate model. We identified urinary sediment characteristics that independently correlated with the presence of some histologic lesions: urinary lipids with mesangial expansion (OR=2.86; 95% confidence interval [95% CI], 1.3 to 6.3), mesangial hypercellularity (OR=2.44; 95% CI, 1.06 to 5.58), and wire loops and/or hyaline deposits (OR=2.89; 95% CI, 1.13 to 7.73); Urinary renal tubular epithelial cells with endocapillary hypercellularity (OR=3.17; 95% CI, 1.36 to 7.39), neutrophils and/or karyorrhexis (OR=4.51; 95% CI, 1.61 to 12.61), fibrinoid necrosis (OR=4.35; 95% CI, 1.48 to 12.74), cellular/fibrocellular crescents (OR=5.27; 95% CI, 1.95 to 14.26), and acute tubular necrosis (OR=2.31; 95% CI, 1.08 to 4.97).

CONCLUSIONS

In a population of patients submitted to kidney biopsy, we found that the presence of some urinary particles (renal tubular epithelial cells, lipids, and dysmorphic erythrocytes), which are seldom reported by automated analyzers, is associated with active proliferative histologic lesions. In this regard, manual urinary sediment evaluation may help to shape the indications for performing a kidney biopsy.

Ulcerating stasis dermatitis of the forearm associated with arteriovenous graft and central vein stenosis

INTRODUCTION

Stasis dermatitis is a pathologic condition of the skin that most commonly occurs in the lower limb, where it is caused by chronic venous insufficiency. Stasis dermatitis of the upper limb is rare.

CASE REPORT

A 45-year-old male, resident in Angola, presented to the emergency department with an ulcer encompassing the entire left forearm. Past medical history comprised arterial hypertension and end stage renal disease treated with hemodialysis. Dialysis access consisted of a left brachial-basilic AV graft obtained 4 years before. The patient also reported that a right internal jugular vein catheter was used previously during the maturation of the left brachial-basilic AV graft. Stenosis of the left brachiocephalic vein was documented at angiography. Angioplasty was performed, with complete resolution of the wound 2 months after admission.

CONCLUSION

The differential diagnosis of extensive ulcer of the forearm must include neoplasms, cellulitis, and/or deep tissue infection with secondary ulceration, but it is also important to maintain suspicion for venous stasis syndrome as a rare but possible cause of these lesions.

MO784: Racial Differences in Vascular Access for Dialysis—Why are Black Patients Prone to Fewer Vascular Access Options?

BACKGROUND AND AIMS

Vascular access (VA) represents a major component for dialysis outcomes, like mortality, morbidity, hospital admission and economical costs.

A well-described phenomenon, is the racial disparity concerning vascular access care, as black patients are associated with fewer fistulae construction and a higher rate of access dysfunction. Different clinical and socio-economical factors have been pointed to explain this association, however concrete vascular data has not been explored. We analyse the anatomical and haemodynamic data, obtained by preoperative ultrasound mapping, in order to prove whether vascular differences explain racial disparities.

METHOD

Retrospective study that included patients referred for the first VA construction and evaluated through ultrasound vascular mapping. Sociodemographic, clinical, vascular data (arterial diameter and peak systolic velocity, PSV; presence of mono or biphasic flow and significant calcification) and vascular mapping conclusions (type of possible VA) were collected.

For racial comparison of collected data, two groups were created, blacks and non-blacks. Appropriate tests for continuous and categorical variables were applied, recurring to SPSS v21.0. Unadjusted and adjusted multivariate logistic regression models were fitted to determine if races are associated with clinical or vascular features.

RESULTS

A total of 102 patients were included. The mean age was 67 ± 16 years, 54% were male and 14% were black and 36% were already on dialysis or kidney transplantation. Hypertension, diabetes mellitus, cardiac insufficiency, coronary disease, peripheral arterial disease and obesity were noted at 94, 48, 34, 25, 17 and 35%, respectively.

Among these, non-black patients presented a higher risk for cardiac insufficiency (P = 0.025).

Concerning arterial evaluation: 16% presented upper brachial bifurcation in one or both arms; 31% presented monophasic or biphasic waveform in any of the principle arterial vessels and 26% presented significant arterial calcification. These qualitative and the radial and brachial diameters and PSV showed no differences between black and non-black patients.

Finally, the feasibility for radiocephalic or brachiocephalic was noted in 67%, whilst in 33% only brachiobasilic or prosthetic fistulae was possible. Black race was found as a predictor for these differences, accounting for a higher probability of scarce options (P = 0.042), the effect that was reinforced when evaluating prosthetic fistulae as the only option (P = 0.027); both conclusions persisted in a multivariate analysis including cardiac insufficiency.

CONCLUSION

Black patients are associated with scarce VA options, such as brachiobasilic or prosthetic fistulas. No substantial differences were identified in arterial, clinical and sociodemographic features, remaining the venous system as the most disabling component in VA construction. The underlying biology is an area to explore, for academic and practical purposes.

A larger sample should be collected to confirm these findings and establish if peripheral venous features underlie racial differences related to VA care in haemodialysis.

MO781: Patients with Scarce Options for the First Arteriovenous Access: Lessons to be Learned from Vascular Mapping

BACKGROUND AND AIMS

The use of doppler ultrasound (DUS) is a non-invasive powerful tool, allowing the morphological and functional characterization of the blood vessels. Once an optimal location for vascular access (VA) creation is obtained, the risk of failure is reduced. Even the use of DUS has improved the VA creation, a significant proportion of patients remains with suboptimal VA, as the laborious umerobasilic fistulae or higher risk prosthetic fistula. Our aim was to identify patients with scarce VA options in the first VA planning, characterizing their demographical and clinical aspects, but also the ultrasound features that are described as having prognosis importance, mostly vessel diameter and calcification findings.

METHOD

We retrospectively analysed a cohort of consecutive chronic kidney disease (CKD) patients that underwent DUS vascular mapping at a tertiary referral hospital from 2018 to 2019. All the DUS were performed by the same operator. Patient characteristics were collected. The DUS data observed were: arterial diameter and peak systolic velocity (VPS) in both arms, presence of mono- or biphasic waveform flow and calcification (quantified according to number of the involved arteries). We defined two groups for VA comparison—patients with scarce VA options (only umerobasilic fistula or prosthetic VA) versus patients whose mapping suggested availability for a radiocephalic or umerocephalic fistulae.

Appropriate tests for continuous and categorical variables were applied, recurring to SPSS v21.0. Unadjusted and adjusted multivariate logistic regression models were fitted to determine which clinical or DUS findings were predictors for scarce VA options.

RESULTS

A total of 153 patients were mapped by DUS, and 102 patients fulfilled the first VA creation criteria. The median age was 71 (58–79) years, 55 (54%) were male, 14 (14%) were black, 27 (28%) were already on dialysis or kidney transplantation. A total of 34 patients (33%) were identified as having scarce AV options, according to DUS. In patients with scarce VA options, there was a significant statistical difference between black race patients (0.042) and use of tobacco (0.041), within all the co-morbidities observed. Concerning arterial measurements, there was no difference in the arterial diameters. However, the radial PSV was lower in the group with fewer VA options (Table). There were more arteries with calcification in these group.

In the multivariate analysis, the arterial calcification was found to be a predictor for scarce VA options [odds ratio (OR) 1.26, 95% confidence interval (95% CI) 1.01–1.58], adjusted for the radial VPS measurements and black race.

CONCLUSION

Starting haemodialysis with a matured and functional VA represents a successful outcome for CKD patients.

Black race and arterial calcification score of the arteries were associated to suboptimal VA, which could identify these patients as having high-risk for morbidity and mortality related to VA. In our observation, the results were similar in both groups, whereas the main difference was on the radial PSV, which was consistently lower in the patients with fewer VA options.

This finding showed that poorer radial haemodynamics precluded radiocephalic fistulae in these patients; otherwise, they are at higher risk for distal hypoperfusion ischaemic syndrome, which aggravates VA prognosis. The use of DUS is increasing in clinical practice due to its importance for the characterization of venous and arterial anatomy. This study, showed that high-risk patients for VA care can be identified before VA creation through a powerful tool as DUS, overcoming classical sociodemographic and clinical risk factors.

MO773: The Impact of the Time on Dialysis and Kidney Transplantation on Arterial Ultrasound Characteristics

BACKGROUND AND AIMS

Vascular accesses (VA) are essential for efficient haemodialysis and preoperative vascular mapping through ultrasound (US) may help surgical planning and improve its outcomes. Several factors can affect vascular quality, hampering the decision about which access to create and affecting VA patency and complications. Our study aims to identify the impact of time on dialysis and/or kidney transplantation in arterial US characteristics.

METHOD

Retrospectively, we analysed a cohort of patients with chronic kidney disease in whom a US vascular mapping was performed for preoperative planning of dialysis access from 2018 to 2019.

Besides demographical characteristics, patients were characterized regarding the presence of diabetes, hypertension, vascular disease (including coronary, cerebrovascular, or peripheral arterial disease), obesity and smoking (present or past).

Vascular indicators were analysed by Doppler US of the arteries in both upper arms, particularly the radial and brachial arteries. Arterial indicators analysed included mean diameter and peak wave velocity (PWV), doppler waveform (mono, bi or triphasic) and calcification on both arms (on a score of 0 to 6).

Patients were divided into three groups regarding whether they had not been transplanted and/or started dialysis (group 1), or if one or both conditions were positive for ˂ 5 years (group 2), or 5 or ≥years (group 3).

Appropriate tests were applied recurring to SPSS v21.0.

RESULTS

A total of 153 patients were included. The mean age was 64.54 ± 16 years, 80 (52.3%) were male, 124 (81.0%) were white, 27 (17.6%) were black and 2 (1.3%) were Asian. Most patients had hypertension (138, 90.2%), 70 (45.8%) had diabetes, 59 (38.6%) had arterial disease, 36 (23.5%) were smokers and 45 (29.4%) were obese. The majority of patients were attending for the first vascular access (102, 66.7%).

Regarding time since dialysis and/or kidney transplant, most patients were on group 1 (91, 59.5%), 46 (30.1%) were on group 2 and 15 (9.8%) were on group 3.

We found that there was a statistically significant correlation between the time since initiation of dialysis and/or kidney transplantation and radial and ulnar mean PWV (P-value 0.004 and 0.004, respectively), but not with their mean diameters. Moreover, this correlation was valid for radial mean PWV between patients on group 1 and group 3 (P-value 0.006, CI 95% 3.88–28.57), and for ulnar mean PWV between patients on group 1 and group 3 (P-value 0.003, CI 95% 6.06–34.69) and between group 2 and group 3 (P-value 0.022, CI 95% 2.02–32.45). No statistically significant correlation was found between the time since kidney transplantation and/or dialysis was started and vascular calcification.

CONCLUSION

Our results show that patients who have been transplanted and/or started dialysis for 5 or more years (and, in the case of ulnar mean PWV, for ˂ 5 years too) have lower radial and ulnar mean PWV than patients who did not. Moreover, there is no statistically significant difference in radial and ulnar mean diameters and calcification between these groups.

End-stage kidney disease (ESRD) is associated with peripheral arterial disease, which has a great impact on patients’ morbidity and mortality and is mainly a manifestation of atherosclerosis. Besides the traditional risk factors, like hypertension or diabetes, some non-traditional risk factors contribute to the high prevalence of PAD in ESRD, like oxidative stress or uraemic retention solutes. Pathologically, this is usually associated with media thickness increase and media calcification. In this study, this phenomenon can be demonstrated by lower peripheral velocities, with less impact in calcification or arterial diameter.

Furthermore, the arterial diameter should not be the sole US indicator when deciding which VA to create, especially in patients on dialysis or transplanted, since it does not reflect the changes in arterial flux that results from several cardiovascular changes.

MO049: Correlation of Findings in Urinary Sediment Microscopy and Histological Lesions in Kidney Biopsy: Red Flags Not to be Missed

BACKGROUND AND AIMS

Urinary sediment (U-Sed) is a noninvasive laboratory test that can be performed by an automated analyzer or manually by trained personnel. Manual U-Sed remains the diagnostic standard because it excels at distinguishing isomorphic from dysmorphic red blood cells, identifying renal tubular epithelial cells, lipids, crystals and the composition of casts. Findings in U-Sed reflect damage that is occurring within the kidney, which can be documented by kidney biopsy. This study aimed to investigate the prevalence of a complete profile of U-Sed particles and its associations with histological lesions on kidney biopsy, regardless of renal diagnosis.

METHOD

This retrospective study included 131 patients who had contemporary manual U-Sed evaluation and kidney biopsy at our institution, from 2018 to 2021. Renal transplant patients were excluded. A comprehensive set of urinary particles and histological lesions were quantified, and we analyzed their associations.

Urinary particles evaluated included casts, erythrocytes, leukocytes, renal tubular epithelial cells, urothelial transitional cells (superficial and deep), lipids, crystals, squamous cells and bacteria. They were semi-quantified from 0 (absent) to 3 + . Renal biopsies samples were reviewed, and a systematic evaluation of 32 histological lesions was performed. When present, lesions were semi-quantified from 0 (absent) to 3 + .

Appropriate tests were performed STATA v.16.1.

RESULTS

We found an elevated frequency of findings suggestive of proliferative renal disease, such as dysmorphic hematuria (n = 71, 54.2%), leukocyturia (n = 62, 47.3%), renal tubular epithelial cells (n = 53, 40.5%) and lipiduria (n = 45, 34.4%), and a low frequency of particles evoking urological damage, such as isomorphic hematuria (n = 29, 22.1%), crystals (n = 12, 9.2%) and urothelial transitional cells (n = 26, 9.9%).

The association of histological lesions and urinary particles was explored with a multivariate model that identified U-Sed characteristics, which favored the presence of acute tubular necrosis, endocapillary hypercellularity, neutrophils and/or karyorrhexis, wire loops and/or hyaline deposits, fibrinoid necrosis and cellular/fibrocellular crescents (summarized in Table 1).

CONCLUSION

In a population of patients submitted to kidney biopsy, we found that the presence of some urinary particles (renal tubular epithelial cells, lipids and dysmorphic erythrocytes), which are seldom reported by automated analyzers, conferred an increased likelihood of active proliferative histological lesions. It is important not to misidentify them, as their presence are red flags for relevant proliferative histological lesions. Moreover, given the flare/remission characteristics of proliferative glomerular disease, U-Sed could play a major role in measuring the degree of activity without requiring repeat kidney biopsies.

Complexes of In(III) with 8-hydroxyquinoline-5-sulfonate in solution: structural studies and the effect of cationic surfactants on the photophysical behaviour

Following previous studies on the complexation in aqueous solutions of 8-hydroxyquinoline-5-sulfonate (8-HQS) with the trivalent metal ions, Al(III) and Ga(III) and various other metal ions, using multinuclear NMR, DFT calculations, UV-vis absorption and luminescence techniques, we have extended our studies on 8-HQS complexation to the trivalent metal ion In(III). The study combines the high sensitivity of luminescence techniques and the selectivity of multinuclear NMR spectroscopy with the structural details accessible through DFT calculations, and aims to obtain a complete understanding of the complexation between the In³⁺ metal ion and 8-HQS, and how this influences the luminescence behaviour. A full speciation study has been performed and, as has been reported for the complexes of 8-hydroxyquinoline (8-HQ), the dominant complexes of 8-HQS with In(III) show marked differences in the complexation behaviour when compared with the equivalent complexes with the other group 13 cations Al(III) and Ga(III). While all three complexes have a 1 : 3 (metal : ligand) stoichiometry, those with Al(III) and Ga(III) show a mer-geometry of the ligands around the metal centre, whereas the fac-geometry is observed for the complexes with In(III). On binding to metal ions, 8-HQS shows a marked increase in the intensity of the fluorescence emission band compared to that of the virtually non-luminescent free ligand. However, the increase for In(III) is less pronounced than with Al(III) or Ga(III). These observations have important implications for the application of the complexes in sensing, light emitting devices (e.g. OLEDs), or as electron transport layers in photovoltaics for solar energy conversion. Furthermore, surfactant complexation is known to improve the fluorescence intensity in metal complexes with 8-HQS, by inhibiting the ligand exchange, as we have reported for complexes of HQS with Al(III) and Ga(III). Accordingly, in view of the development of applications in either sensing or optoelectronics, our interest also includes the study of HQS complexes of In(III) in the presence of cationic surfactants, in comparison with previous results with Al(III) and Ga(III).

[A rare presentation of kidney allograft intolerance syndrome: Bullous pemphigoid]

Bullous pemphigoid is an autoimmune bullous cutaneous disease. We report the case of a 60 year-old male patient whose kidney allograft failed and was on hemodialysis for the previous 16 months. After tapering immunosuppressive medication, he presented simultaneous bullous eruption and kidney allograft intolerance syndrome. Investigation showed a positive BP180 anti-basement membrane zone antibody and skin biopsy was consistent with bullous pemphigoid. The patient was treated with corticotherapy and bullous pemphigoid resolved. The development of new onset diabetes and concerns over long term immunosuppression, halted the decision to continue corticotherapy and the patient underwent graft nephrectomy, with resolution of the kidney allograft intolerance syndrome without recurrence of the bullous disease. The occurrence of bullous pemphigoid in patients with failed renal allograft is rare, with only eleven cases reported in literature. This case illustrates how graft nephrectomy can provide a definitive cure to bullous pemphigoid in this setting.

MO774PREDICTIVE FACTORS FOR PROSTHESIC ARTERIOVENOUS FISTULA OPTION BY DUPLEX DOPPLER ULTRASOUND VASCULAR MAPPING

Background and Aims

Vascular access (VA) remains the lifeline for hemodialysis (HD) patients. Arteriovenous fistulas (AVF) are recommended over prosthesic arteriovenous fistula (PAF). However, the choice of the type of VA still reflects local practice differences and patient-specific demographic and clinical factors. Duplex Doppler ultrasound (DDU) has been shown to be useful in evaluation of both structural and functional aspects of the peripheral vessels, and is emerging as the preferred method for VA planning. Our aim was to find predictive factors for PAF creation in our population, i.e. when AVF was not feasible.

Method

We retrospectively analysed a cohort of chronic kidney disease patients who underwent DDU vascular mapping for preoperative planning of HD access at a tertiary referral centre from 2019 to 2020. All the exams were performed by the same DDU operator. Demographic, clinical and DDU characteristics were studied. Continuous variables were recorded as means (±SD) for normally distributed data or as medians (interquartile ranges) for non-normally distributed data. Comparisons were made using t tests or Wilcoxon rank sum tests as appropriate. Categorical variables were evaluated by frequency distribution and recorded as proportions. Comparisons were made using the x2 test. Unadjusted and adjusted multivariate logistic regression models were fitted to identify risk factors to PAF creation due to not being a good candidate for AVF.

Results

A total of 252 patients were included. The mean age was 65±16 years, 144 (57%) were male, 211 (84%) where white, 40 (16%) were black and 1 (0.4%) was asian. Two hundred and thirty seven (94%) patients were right-handed and 186 (74%) were being evaluated for the first vascular access. The majority had arterial hypertension (HT) (205 (81%)); 98 (39%) had Diabetes Mellitus (DM), 89 (35%) were current or past smoker and 72 (29%) were obese. Most patients were considered appropriate candidates for AVF (207, 82%), whereas 45 (18%) were assigned to PAF. Figure 1 compares the DDU’s arterial indexes of each group. In a multivariate logistic regression model adjusted for age, sex, HT, DM and obesity, black race was found to be a predictor of being a candidate for PAV creation (OR 2.46; CI 95% 1.05-5.71; p-value 0.036).

Conclusion

Our study revealed that black race is an independent factor for PAV creation even after adjusting for classic risk factors as age, DM or HT. Long known insidious factors, such as poor socioeconomic status or poor access to medical care, have been pointed as justifiers to this disparity. However, facing the PAF-associated risks, we believe that further work must be done to clarify potential involved anatomical factors and potential reversible factors. Those patients have been described throughout the literature as presenting with higher risk of VA failure and severe peripheral arterial disease. In parallel we found that radial and ulnar arteries diameters and radial pulse wave velocity (PWV) in DDU were significantly lower in PAV-submitted patients, suggesting distal arterial compromise and stiffness. Our work has some limitations: neither vein parameters nor VA outcomes were analysed. However, it introduces a relationship between the black race and worse arterial indexes, and their impact on the choice of type of VA, as they seem not to be good candidates for AVF.

MO773THE VASCULAR REALITY BEHIND ULTRASOUND VASCULAR MAPPING: WHICH FACTORS PREDICT THE BEST CANDIDATES FOR RADIOCEPHALIC ARTERIOVENOUS FISTULA?

Background and Aims

Vascular accesses (VA) are key components for efficient hemodialysis. Arteriovenous fistulas (AVF) are recommended over arteriovenous graft (AVG), but deciding the type and location of a VA is challenging. Preoperative vascular mapping before surgical creation of VA, especially trough ultrasound (US), is helpful in this decision, contributing to improve AVF e AVG outcomes.

Our study aims to identify patient factors associated with appropriate arterial US parameters that predict feasibility for radiocephalic fistula creation.

Method

We analyzed a cohort of chronic kidney disease patients who underwent US vascular mapping for preoperative planning of dialysis access from 2019 to 2020, in a tertiary referral center. Patients were characterized based on its demographical characteristics, and the presence of diabetes, hypertension, obesity, and smoking. Arterial indicators were analyzed by ultrasound techniques in both upper arms, including radial, ulnar and brachial arteries. Those indicators included arterial diameter, calcification, doppler wave form, and pulse wave velocity.

Continuous variables were recorded as means (±SD) for normally distributed data and as medians (interquartile ranges) for nonnormally distributed data. Comparisons were made using t tests or Wilcoxon rank sum tests as appropriate. Categorical variables were examined by frequency distribution and recorded as proportions. Comparisons were made using the x2 test. Unadjusted and adjusted multivariate logistic regression models were fitted to identify predictors for a good candidate for radiocephalic arteriovenous fistula.

Results

A total of 252 patients were included. The mean age was 65±16 years, 144 (57%) were male, 211 (84%) where white, 40 (16%) were black, and 1 (0.4%) was asian. Most had arterial hypertension (205, 81%), 98 (39%) had diabetes mellitus, 89 (35%) were smokers, and 72 (29%) were obese. The majority of patients were attending for the first VA (186; 74%).

Most patients were considered appropriate candidates for arteriovenous fistula creation (207, 82%), whereas 45 (18%) were assigned to PTFE graft. Obesity and male sex were found to be predictors for being a good candidate for radiocephalic arteriovenous fistula in a multivariate logistic regression model adjusted for age, hypertension, and diabetes (OR 3.21, CI 95% 1.63-6.32, p-value 0.001 and OR 2.09, CI 95% 1.07-4.08, p-value 0.031, respectively). Figure 1 presents the arterial indicators analyzed during ultrasound mapping, including both upper limbs.

Conclusion

Our results show that obesity and male sex are predictors for radiocephalic arteriovenous fistula creation. While female sex has long been known to be a risk factor for VA failure, possibly because of worse arterial indicators, an association between obesity and higher probability of distal AVF creation has not been established yet. Comparison between arterial indicators in obese and nonobese patients shows that obese patients generally have better arterial indicators, especially higher pulse wave velocities, and less arterial calcification.

Given that some studies show an association between obesity and shorter fistula survival (due to higher secondary failure rate), our results may come as. A possible explanation for this difference is that obesity may exert a physical protective effect of the forearm vascular bed against iatrogenic damage (blood sampling and vessel cannulation). Besides that, factors other than vascular indicators may contribute to ulterior VA failure, like the proinflammatory state in obese patients and its consequent myointimal hyperplasia.

However, our conclusions are based on preoperative findings, and not on VA outcomes, especially its patency and complications. Moreover, which further help to determine the better location for a VA creation, were not evaluated in this study.

Outcomes of excessive alcohol drinkers without baseline evidence of chronic liver disease after 15 years follow-up: Heavy burden of cancer and liver disease mortality

Background

Most long-term heavy drinkers do not have clinically evident chronic liver disease (CLD). However, at any time-point, their risk of developing CLD remains unknown. We aimed to evaluate the long-term outcomes of a group of heavy drinkers, without evidence of CLD at baseline.

Methods

A cohort of 123 long-term heavy drinkers without CLD were prospectively recruited in 2002 and retrospectively followed until 2018.

Results

At baseline (2002), median alcohol consumption was 271±203g/day during 21.5±20 years, 65% being abstinent during the previous 1.75±5 months. Patients were followed for 14±3 years. During follow-up, 53% reported any alcohol intake. Alcohol consumption during follow-up associated weakly with either 1- or 6-months previous abstinence at baseline. Until 2018, progression to CLD occurred in 6%, associating with years of alcohol intake during follow-up (OR 1.15 [1.01–1.31]) and baseline alkaline-phosphatase (OR 1.05 [1.01–1.10]). During follow-up, being abstinent for at least 1 year positively associated with CLD-free survival. 27% died (55% of cancer–mostly oropharyngeal cancer, 27% of cardiovascular disease, and 9% of liver disease), with a mean age of 71 years [69–74] (10 years less than the expected in the Portuguese population). Achieving abstinence for at least 1 year positively associated with overall survival, while smoking, and hepatic steatosis at baseline associated negatively.

Conclusion

Long-term heavy drinkers seemed to have a decreased life expectancy compared with the overall Portuguese population. Cancer was the main cause of death. Our results suggest that progression to CLD depends mostly on continued alcohol intake. Alcohol abstinence, even if temporary, seems to decrease the risks of CLD and mortality.

Oxocomplexes of U(vi) with 8-hydroxyquinoline-5-sulfonate in solution: structural studies and photophysical behaviour

Multinuclear (¹H and ¹³C) NMR, and Raman spectroscopy, combined with DFT calculations, provide detailed information on the complexation between U(vi) oxoions and 8-hydroxyquinoline-5-sulfonate (8-HQS) in aqueous solution. Over the concentration region studied, U(vi) oxoions (uranyl ions) form one dominant complex with 8-HQS in water in the pH range 3-6, a mononuclear 1 : 2 (metal : ligand) complex, with the metal centre (UO₂²⁺) coordinated to two 8-HQS ligands, together with one or more water molecules. An additional minor 1 : 1 complex has also been detected for solutions with a 1 : 1 metal : ligand molar ratio. The geometry of the dominant complex is proposed based on the combination of the NMR and Raman results with DFT calculations. Further information on the electronic structure of the complex has been obtained from UV/visible absorption and luminescence spectra. The complex of U(vi) and 8-HQS is non-luminescent, in contrast to what has been observed with this ligand and many other metal ions. We suggest that this is due to the presence of low-lying ligand-to-metal charge transfer (LMCT) states below the emitting ligand-based and uranyl-based levels which quench their emission. These studies have fundamental importance and are also relevant in the context of environmental studies, and the water soluble ligand 8-HQS has been chosen for application in uranium remediation of aqueous environments.

[Endobronchial ultrasound-guided transbronchial needle aspiration for lung cancer diagnosis and staging in 179 patients]

BACKGROUND

Linear endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an important minimally invasive procedure for non-small cell lung cancer (NSCLC) staging. It is also a valid method for diagnosing extraluminal lesions adjacent to the tracheobronchial tree.

AIM

To evaluate our EBUS-TBNA performance regarding diagnostic yield, safety and learning curve for lung cancer diagnosis and staging.

MATERIAL AND METHODS

All patients undergoing EBUS-TBNA for lung cancer diagnosis or staging were included. They were divided into three different groups: paratracheal and parabronchial masses sent for diagnosis (Group 1); peripheral lung lesions with abnormal mediastinal lymph nodes sent for diagnosis and staging (Group 2); NSCLC patients sent for mediastinal staging (Group 3). The learning curve was assessed for yield, accuracy, procedure time, size and number of lesions punctured per patient.

RESULTS

A total of 179 patients were included and 372 lesions were punctured. The overall yield and accuracy were 88% and 92.7%, respectively. In Group 1, EBUS-TBNA was performed in 48 patients and sensitivity was 86.1% and accuracy was 87.5%. For the 87 patients included in Group 2, yield was 86.7%, accuracy was 93.1% and cancer prevalence was 51.7%. The diagnostic yield and accuracy in Group 3 was 95% and 97.7% respectively. EBUS-TBNA practice led to an increase number of sites punctured per patient in a shorter time, without complications.

CONCLUSION

EBUS-TBNA is an effective method for diagnosing and staging lung cancer patients. The procedure is clearly safe. Handling and performance improves with the number of procedures executed.

[Vaccination coverage in the first year of life in 4 cities of the state of São Paulo, Brazil]

Immunization is an important disease prevention measure, and evaluating the effectiveness of immunization programs is crucial to ensuring their success. This study describes the results of a household survey in four cities in the state of São Paulo, Brazil: Francisco Morato, Guarulhos, Osasco, and São Paulo. The survey was done in order to estimate immunization coverage for the cohort of children born in 1996. The city of São Paulo was divided into five strata, according to socioeconomic and living conditions. The survey followed the methodology that the Pan American Health Organization recommends for immunization coverage surveys. The proportion of children who had received a complete set of the recommended vaccinations at the time of the interview, taking into account both oral reports and information recorded on the children's immunization cards, was above 90% for all the cities except Francisco Morato, which had the worst living conditions. In the city of São Paulo, the worst coverage was found in the lowest and highest strata. When only the doses received during the first year of life were considered, the coverage was not adequate to produce herd immunity. The use of private vaccination services was higher in the areas with better living conditions. The difference between the coverage calculated based on data from health services and the coverage calculated based on the survey was inversely proportional to living conditions. Our results suggest that surveys similar to the one described here should be carried out in other cities. Employees who provide vaccination services should be trained to correctly record vaccination data. In addition, it is important to make health professionals aware of the official immunization calendar, and to facilitate the public's access to health services.