Pathophysiology of COVID-19-associated acute kidney injury

Although respiratory failure and hypoxaemia are the main manifestations of COVID-19, kidney involvement is also common. Available evidence supports a number of potential pathophysiological pathways through which acute kidney injury (AKI) can develop in the context of SARS-CoV-2 infection. Histopathological findings have highlighted both similarities and differences between AKI in patients with COVID-19 and in those with AKI in non-COVID-related sepsis. Acute tubular injury is common, although it is often mild, despite markedly reduced kidney function. Systemic haemodynamic instability very likely contributes to tubular injury. Despite descriptions of COVID-19 as a cytokine storm syndrome, levels of circulating cytokines are often lower in patients with COVID-19 than in patients with acute respiratory distress syndrome with causes other than COVID-19. Tissue inflammation and local immune cell infiltration have been repeatedly observed and might have a critical role in kidney injury, as might endothelial injury and microvascular thrombi. Findings of high viral load in patients who have died with AKI suggest a contribution of viral invasion in the kidneys, although the issue of renal tropism remains controversial. An impaired type I interferon response has also been reported in patients with severe COVID-19. In light of these observations, the potential pathophysiological mechanisms of COVID-19-associated AKI may provide insights into therapeutic strategies.

Prostatic Artery Embolization in Refractory Hematuria of Prostatic Origin

Hematuria of prostatic origin has multiple etiologies including benign prostatic hyperplasia (BPH), iatrogenic urological trauma, prostate cancer, and radiation therapy. Hematuria secondary to benign prostatic hyperplasia can occur because of the increased vascularity of the primary gland, itself, or because of the vascular re-growth following a transurethral resection of the prostate. Prostatic hematuria usually resolves with conservative measures; however, refractory hematuria of prostatic origin may require hospitalization with treatment with blood transfusions, repeated indwelling urinary catheterization, and continuous bladder irrigation. Prostate artery embolization is an emerging minimally invasive procedural therapy for men with BPH that was originally utilized for the treatment of refractory hematuria of prostatic origin . This article aims to summarize the currently available evidence around prostate artery embolization for the treatment of refractory hematuria of prostatic origin.

An overview of the multi-pronged approach in the diagnosis of Alport syndrome for 22 children in Northeast China

BACKGROUND

Alport syndrome (AS) is a kind of progressive hereditary nephritis induced by mutations of different genes that encode collagen IV. The affected individuals usually develop hematuria during childhood, accompanying with gradual deterioration of renal functions. In this study, the multi-pronged approach was employed to improve the diagnosis of AS.

METHODS

Twenty-two children were diagnosed and treated at the Department of Pediatric Nephrology of Jilin University First Hospital between January 2017 and January 2020 using the multi-pronged approach. The following information was collected from patients, including age of onset, age at diagnosis, clinical manifestations, family history, renal pathology and genotype.

RESULTS

All these 22 children were diagnosed with Alport syndrome according to the diagnostic criteria formulated by the Japanese Society of Nephrology (2015), among them, only 13 children met the diagnostic criteria released in 1988. All the 22 patients presented with hematuria, and proteinuria to varying degrees was observed in some patients. Three children suffered from hearing loss, but no child in the cohort had any visual problem or renal failure. Meanwhile, five patients were estimated to be at Stage 2, whereas the remaining 17 cases were at Stage 0. Renal biopsies were performed in 18 patients, including 14 showing glomerular basement membranes (GBM)-specific abnormalities. Moreover, 13 children were detected with mutations of genes encoding collagen IV.

CONCLUSIONS

The multi-pronged approach helps to improve the diagnosis of AS. Most patients do not have renal failure during childhood, but close assessment and monitoring are necessary. Also, the advancements in treatment are reviewed.

Macroscopic hematuria as a risk factor for hypertension in ageing people with hemophilia and a family history of hypertension

Ageing people with hemophilia (PWH) have a higher prevalence of hypertension than the general population. This study aimed to determine whether macroscopic hematuria was associated with hypertension in PWH in a post hoc analysis using data from a cross-sectional study conducted by the ADVANCE Working Group (the H3 study), which included PWH ≥ 40 years of age. Data from 16 contributing centers, located in 13 European countries and Israel, were analyzed using logistic regression models. Of 532 recruited PWH in the H3 study, 117 had hypertension and a positive family history of hypertension (hypertension FH+), 75 had hypertension and a negative family history of hypertension (hypertension FH-), 290 had no diagnosis of hypertension, and the remaining 50 had missing hypertension data. Logistic regressions showed that macroscopic hematuria was associated with hypertension FH+, both in the univariate (OR = 1.84 [1.17-2.90], P = .01) and in the multivariate model (OR = 1.80 [1.03-3.16], P = .04). Macroscopic hematuria was not associated with hypertension FH-. Moreover, in a multivariate logistic regression the odds of hypertension FH+ were increased with the number of macroscopic hematuria episodes. The association between macroscopic hematuria and hypertension was significant for PWH with a family history of hypertension.

Incidence of Visible Hematuria Among Antithrombotic Agents: A Systematic Review of Over 175,000 Patients

OBJECTIVE

To determine the probability of visible hematuria with antithrombotic agents and to evaluate association of urologic etiology in antithrombotic-related hematuria.

METHODS

Preferred Reporting Items in Systematic Reviews and Meta-Analyses guidelines were followed to conduct a systematic review using search engines PUBMED and SCOPUS with the terms "(hematuria) OR (haematuria) OR urinary bleeding)) AND ((anticoagulants) OR anticoagulation) OR noac) OR novel anticoagulants) OR antiplatelet) OR dabigatran) OR rivaroxaban) OR apixaban) OR warfarin) OR aspirin) OR heparin) OR dipyridamole)." Raw data were used to perform a pooled analysis. Chi-square and logistic regression analysis were used for statistical analyses.

RESULTS

Twenty-two studies describing 175,114 patients met inclusion criteria. Odds ratio of hematuria with warfarin to rivoraxaban was 33 and warfarin to dabigatran was 16. The odds ratio of hematuria for oral anticoagulant (26.7%) to prophylactic parenteral anticoagulant (1.1%) agents was 9.6. Antiplatelet agents are 76 times less likely to cause hematuria compared to anticoagulants. Odds of hematuria with aspirin were 6.7 times the odds with clopidogrel and 3.5 times the odds with ticagrelor. Dabigatran was 198 times more likely to cause major hematuria compared to warfarin, whereas clopidogrel is 1.2 times more likely to cause major hematuria compared to aspirin. Urologic pathology was identified in 44% (234/532) of cases, malignancy in 24%.

CONCLUSION

Warfarin use poses the greatest risk for hematuria but is unlikely to cause major hematuria, whereas novel antithrombotic agents are more commonly associated with major hematuria. This review further characterizes the risk profile of antithrombotic agents and associated hematuria to equip clinicians with knowledge to choose an appropriate antithrombotic agent in patients with high-risk hematuria.

Treatment and clinicopathological characteristics of lupus nephritis with anti-neutrophil cytoplasmic antibody positivity: a case-control study

OBJECTIVE

To assess the clinical features, pathological presentations, treatments and outcomes of lupus nephritis (LN) with anti-neutrophil cytoplasmic antibody (ANCA) positivity.

DESIGN

A case-control study.

METHODS

Patients (n=49) were retrospectively included from Jinling Hospital in China if presenting with biopsy-proven ANCA-positive LN between 1985 and 2008. Clinicopathological characteristics and outcomes were analysed and compared with those of a control group (n=1279). We further compared treatment responses and outcomes of ANCA-positive LN patients based on the treatment issued.

RESULTS

The study included 40 women and 9 men (median age 33 years at biopsy): 38 with myeloperoxidase (MPO)-ANCA, 7 with proteinase 3 (PR3)-ANCA and 4 with double positivity. ANCA-positive LN patients exhibited higher haematuria, serum creatinine levels and systemic lupus erythematosus disease activity index scores. On pathological evaluation, class IV LN was predominant, accounting for 61.22% of cases. Light microscopy revealed significantly higher activity index and chronicity index scores, including cellular crescents, interstitial inflammation, tubular atrophy and interstitial fibrosis. ANCA-positive LN patients receiving mycophenolate mofetil as induction therapy had a higher remission rate and better renal outcomes than those receiving cyclophosphamide. During follow-up, end-stage renal disease developed in seven (14.29%) ANCA-positive LN patients, all of them were MPO-ANCA positive.

CONCLUSIONS

The characteristics of ANCA-positive LN were massive haematuria and advanced renal insufficiency. We observed a higher remission rate and better prognoses when using mycophenolate mofetil than when using cyclophosphamide as induction therapy.

Difenacoum Poisoning as a cause of Haematuria

A man presented with frank haematuria and a grossly prolonged prothrombin time. He was later found to have taken an overdose of difenacoum — a 'superwarfarin' rodenticide. The diagnosis was confirmed by a serum concentration of difenacoum of 0.6 μg ml-1. Overdosage with superwarfarins is discussed and the need for prolonged treatment with vitamin K1 highlighted.

Haematuria on the Spanish Registry of Glomerulonephritis

Recent studies suggest a pathogenic role for glomerular haematuria among renal function. However, there is no data on the prevalence of haematuria from a large renal biopsy registry. We analysed the prevalence of gross (GH) and microscopic (mH) haematuria in 19,895 patients that underwent native renal biopsies from the Spanish Registry of Glomerulonephritis. Haematuria's overall incidence was 63% (GH 8.6% and mH 55.1%), being more frequent in males (64.7% vs. 62.4%). GH was more prevalent in patients <18 years (21.3% vs. 7.7%). The commonest clinical presentation associated with GH was acute kidney injury (31.5%) and IgA Nephropathy (IgAN) (33.6%) was the most frequent histological finding. GH patients showed a significantly (p < 0.05) lower eGFR and proteinuria levels as compared with patients with mH and without haematuria. Moreover, mH was more prevalent in adults (56.3%). Nephrotic syndrome was the commonest clinical presentation in mH patients (32.2%) and IgAN (18.5%) the most frequent histological finding. In conclusion, haematuria, is a frequent urinalysis finding in patients underwent native renal biopsy. The most frequent histological finding in both GH and mH is IgAN. Whereas, GH is more frequent in young males with acute kidney injury, mH is commoner among adults with nephrotic syndrome.

Isolated microscopic haematuria of glomerular origin: clinical significance and diagnosis in the 21st century

Isolated microscopic, or non-visible, haematuria of glomerular origin was previously regarded a benign finding, but it is now known that, even in the absence of proteinuria, hypertension or renal impairment at presentation, haematuria is associated with increased risk of kidney failure in the long term. The most common causes of isolated microscopic haematuria among children and young adults are IgA nephropathy, Alport syndrome (AS), and thin basement membrane nephropathy (TBMN). AS, which is usually inherited as an X-linked or autosomal recessive trait, and TBMN, which is usually autosomal dominant, are caused by mutations in the genes encoding type-IV collagen, an abundant component of the glomerular basement membrane. A detailed family history with screening of at-risk relatives is important, allowing prompt diagnosis of affected relatives and helping determine the mode of transmission. As costs fall and availability increases, genetic testing is increasingly being used in clinical practice to provide diagnostic and predictive information for patients and their families.

Revisiting clinical differences between hypersensitivity vasculitis and Henoch-Schönlein purpura in adults from a defined population

OBJECTIVES

Hypersensitivity vasculitis (HV) and Henoch-Schönlein purpura (HSP) are the most common entities included within the category of cutaneous vasculitis (CV). Palpable purpura and histological changes characterised by the presence of leukocytoclastic vasculitis are common in both conditions. Therefore, considerable overlap between them is often seen. It is especially true when the CV occurs in adults. To further establish clinical differences between these two conditions, in the present study we assessed the main clinical differences between HV and HSP in a wide and unselected series of adults with CV from a defined population.

METHODS

We reviewed the clinical records of 297 consecutive adults (age >20 years) seen at a single centre between January 1975 and December 2012 that were classified as having HSP or HV according to the criteria proposed by Michel et al. (J Rheumatol 1992; 19: 721-8).

RESULTS

Based on the inclusion criteria, 102 adult patients (71 men/31 women) were classified as HSP and 195 (104 men/91 women) as HV. The mean age was similar in both groups (55.8±16.5 years in HSP and 56.8±18.3 years in HV). Precipitating events, usually an upper respiratory tract infection and/or drug intake, were more frequently observed in HV. Both at the beginning of the disease and when the CV was established clinical manifestations were more frequent in patients with HSP than in those with HV. It was the case for gastrointestinal (57.4% vs. 6.8%; p<0.001), joint (51.5% vs. 36.6%; p=0.01) and renal involvement (86.3% vs. 18.3%; p<0.001). Corticosteroid (56.7% vs. 22%; p<0.001) and cytotoxic drug (19.4% vs. 3.2%; p<0.001) use was also more common in patients with HSP. After a median follow-up of 15.5 (interquartile range- IQR; 3-37) months in HSP and 4 (IQR; 2-12) months in HV, the outcome was better in HV than in HSP. In this regard, complete recovery (72.6% vs. 85.4%; p=0.01) was more commonly observed in HV while residual renal involvement (15.3% vs. 4.2%; p<0.001) was more common in HSP. The disease relapsed in 35.3% of patients with HSP and in 24.4% with HV (p=0.07).

CONCLUSIONS

Our results confirm the claim that these two diseases presenting with similar cutaneous involvement are certainly two separate entities with greater systemic involvement and less favourable outcome in HSP.

The use of molecular analyses in voided urine for the assessment of patients with hematuria

Introduction

Patients presenting with painless hematuria form a large part of the urological patient population. In many cases, especially in younger patients, the cause of hematuria is harmless. Nonetheless, hematuria could be a symptom of malignant disease and hence most patients will be subject to cystoscopy. In this study, we aimed to develop a prediction model based on methylation markers in combination with clinical variables, in order to stratify patients with high risk for bladder cancer.

Material and Methods

Patients (n=169) presenting with painless hematuria were included. 54 patients were diagnosed with bladder cancer. In the remaining 115 patients, the cause of hematuria was non-malignant. Urine samples were collected prior to cystoscopy. Urine DNA was analyzed for methylation of OSR1, SIM2, OTX1, MEIS1 and ONECUT2. Methylation percentages were calculated and were combined with clinical variables into a logistic regression model.

Results

Logistic regression analysis based on the five methylation markers, age, gender and type of hematuria resulted in an area under the curve (AUC) of 0.88 and an optimism corrected AUC of 0.84 after internal validation by bootstrapping. Using a cut-off value of 0.307 allowed stratification of patients in a low-risk and high-risk group, resulting in a sensitivity of 82% (44/54) and a specificity of 82% (94/115). Most aggressive tumors were found in patients in the high-risk group. The addition of cytology to the prediction model, improved the AUC from 0.88 to 0.89, with a sensitivity and specificity of 85% (39/46) and 87% (80/92), retrospectively.

Conclusions

This newly developed prediction model could be a helpful tool in risk stratification of patients presenting with painless hematuria. Accurate risk prediction might result in less extensive examination of low risk patients and thereby, reducing patient burden and costs. Further validation in a large prospective patient cohort is necessary to prove the true clinical value of this model.

Clinical features associated with a rapid decline in renal function among Japanese patients with type 2 diabetes mellitus: microscopic hematuria coexisting with diabetic retinopathy

Four patients who exhibited the greatest decline in the estimated glomerular filtration rate [12.3-23.5 ml/min/1.73 m(2)/year] among 320 patients with type 2 diabetes and were followed for a median of 6.8 years had several clinical features in common, including marked albuminuria, microhematuria, retinopathy and poor medication adherence.

Incidence of end-stage renal disease in the Turkish-Cypriot population of Northern Cyprus: a population based study

BACKGROUND

This is the first report of the incidence and causes of end-stage renal disease (ESRD) of the Turkish-Cypriot population in Northern Cyprus.

METHODS

Data were collected over eight consecutive years (2004-2011) from all those starting renal replacement therapy (RRT) in this population. Crude and age-standardised incidence at 90 days was calculated and comparisons made with other national registries. We collected DNA from the entire prevalent population. As an initial experiment we looked for two genetic causes of ESRD that have been reported in Greek Cypriots.

RESULTS

Crude and age-standardised incidence at 90 days was 234 and 327 per million population (pmp) per year, respectively. The mean age was 63, and 62% were male. The age-adjusted prevalence of RRT in Turkish-Cypriots was 1543 pmp on 01/01/2011. The incidence of RRT is higher than other countries reporting to the European Renal Association - European Dialysis and Transplant Association, with the exception of Turkey. Diabetes is a major cause of ESRD in those under 65, accounting for 36% of incident cases followed by 30% with uncertain aetiology. 18% of the incident population had a family history of ESRD. We identified two families with thin basement membrane nephropathy caused by a mutation in COL4A3, but no new cases of CFHR5 nephropathy.

CONCLUSIONS

This study provides the first estimate of RRT incidence in the Turkish-Cypriot population, describes the contribution of different underlying diagnoses to ESRD, and provides a basis for healthcare policy planning.

[Urogenital tuberculosis today]

In order to analyze the structure of urogenital tuberculosis, retrospective analysis of medical records of 131 patients with newly diagnosed urogenital tuberculosis observed in the Novosibirsk Regional TB Dispensary from 2009 to 2011 was performed. The renal tuberculosis is main form in the structure is urotuberculosis, detected in 75% of patients, and widespread destructive forms of the disease were diagnosed in more than half of cases. Isolated nephrotuberculosis was more often diagnosed in women--56.8%. 15.9% of patients had asymptomatic nephrotuberculosis; one-third of patients complained of pain in the lumbar region and frequent painful urination (35.2 and 39.8%, respectively); symptoms of intoxication were present in 17% of patients, renal colic--in 9.1%, and gross hematuria--in 7.9% of patients. Mycobacteriuria in isolated nephrotuberculosis was detected in 31.8% of cases. Acute tuberculous orchiepididymitis developed in 35.7% of patients, hemospermia was observed in 7.1% of patients, dysuria was in 35.7% of patients. The pain in the perineum, frequent painful urination (both by 31.6%), hemospermia (26.3%) were main complaints in prostate tuberculosis. Mycobacteria was detected in 10.5% of cases. It was found that urogenital tuberculosis has no pathognomonic symptoms; the most alarming manifestations include long-term dysuria, hematuria, hemospermia.

[Kidney function in oncologic patients after cisplastin chemotherapy]

During examination of kidney function under cisplastin chemotherapy in oncologic patients the nephrotoxicity of the drug have been shown during 24 hours after administration. We found that in 24 hours after injection ofcisplastin in the dose 50 mg/m2 of the surface of the body, the excretion of creatinine, sodium, potassium, osmotic active compounds and chlorides is increased more than two times, indicating for disorder in osmolality, volume and ionic regulation of kidney function. The determined peculiarities are consequences of kidney injuries, which are confirmed by an increase in erythrocyte- and leucocyteuria. We showed that alterations in homeostatic kidney function is due to damage of renal tubules. Our study necessitates a need for renal protection during the whole period of cisplastin chemotherapy.

Severe cyclophosphamide-induced haemorrhagic cystitis treated with hyperbaric oxygen

AIM

Cyclophosphamide-induced haemorrhagic cystitis (CHC) is an uncommon but well-recognised condition caused by a metabolite, acrolein, which is toxic to the urothelium. Based on similarities in the histopathology of radiation- and chemotherapy-induced haemorrhagic cystitis, benefit from hyperbaric oxygen therapy (HBOT) has been proposed. HBOT produces an increased oxygen partial pressure diffusion gradient between the circulation and surrounding tissues, which enhances neutrophil function and fibroblast and macrophage migration into damaged hypoxic soft tissue, promoting collagen formation, fibroblast growth, angiogenesis and white-cell bacterial killing. There are only isolated case reports of HBOT for CHC, in the literature so we reviewed the New Zealand experience with HBOT in CHC.

METHOD

The case records of all patients with CHC referred to the three hyperbaric medicine units in New Zealand between 2000 and 2007 were reviewed retrospectively.

RESULTS

Six patients, with life-threatening haemorrhage at the time of referral for HBOT weeks or months after initial presentation with CHC, were identified. Cessation of bleeding occurred in all six patients after 14 to 40 HBOT, without complications. All patients remained clear of haematuria at 11 to 36 months follow-up.

CONCLUSIONS

We recommend the use of HBOT in the management of intractable cyclophosphamide-induced haemorrhagic cystitis as an effective and low-risk therapy.

Interpretation of renal volume in autosomal dominant polycystic kidney disease and relevant clinical implications

Autosomal dominant polycystic kidney disease (ADPKD) is the most common life-threatening hereditary disease of the kidney. It presents with progressive enlargement of the kidneys with numerous cysts that distort the parenchyma and result in progressive decline in kidney function. Autosomal dominant polycystic kidney disease is genetically modified with the responsible genes localized to separate loci on chromosome 16 (PKD1 gene), accounting for the majority of ADPKD cases, and chromosome 4 (PKD2 gene), accounting for the remainder. This review discusses the current understanding of the pathogenesis of ADPKD, focusing on renal volume and its pivotal role on the manifestations of the disease. Specifically, activation of the renin-angiotensin-aldosterone system, hypertension, left ventricular hypertrophy, kidney function deterioration, pain, and hematuria are examined as consequences of renal volume increase. Recent developments on diagnostic modalities and criteria of the ADPKD are also discussed.

Microscopic hematuria is associated with low bone mineral density in aged women and men

Little is known concerning renal or urological risk factors for osteoporosis. The aim of this study was to explore an association between urinalysis and bone mineral density (BMD) in 4,835 Japanese adults. Participants were 4,835 individuals (female 3,683; male 1,152) aged 50 years and over who received a health check-up between January 1995 and March 2006 in Japan. BMD of the distal radius and ulna of the non-dominant forearm was measured by the dual-energy X-ray absorptiometry (DXA) method using a DTX-200 Dexacare osteometer (Osteometer MediTech A/S, Rødovre, Denmark). Urine variables were protein, and red blood cells (RBCs) and white blood cells (WBCs) in urine sediment (categorized as <1, 1-4, 5-9, or >or=10 cells per high-power microscopic field). Average age was 58.9 years (SD 5.6) in women, and 60.5 years (SD 6.2) in men. Simple linear regression analysis showed that urinary RBCs were associated with BMD in women (beta = or-5.88 x 10(-3), R (2) = 0.004, p < 0.0001) and men (beta = or-1.34 x 10(-2), R (2) = 0.013, p = 0.0001). These associations held when possible confounders were adjusted (beta = or-2.05 x 10(-3), R (2) = 0.001, p = 0.0338 for women and beta =or -5.67 x 10(-3), R (2) = 0.006, p = 0.0163 for men). Microscopic hematuria is associated with forearm BMD in women and men aged 50 years and over. Further studies should be conducted to determine the mechanisms underlying this association.

Clinical presentation and outcome of autosomal dominant polycystic kidney disease in Pakistan: a single center experience

OBJECTIVE

To delineate clinical presentation and outcome of Autosomal Dominant Polycystic Kidney Disease (ADPKD) in terms of need for renal replacement therapy of kidney transplantation in Pakistani patients.

METHODS

Patients with ADPKD were identified using strict clinical criteria. Medical charts were evaluated retrospectively for initial presenting complaints, co-morbids, family history of ADPKD, any palpable mass on abdominal examination, cardiac examination for any abnormal finding and use of any anti-hypertensive drugs. Laboratory parameters were assessed. Chi square and Logistic regression analyses at 95% CI were used for statistical significance. A p value of less 0.05 was considered statistically significant.

RESULTS

A total of 56 patients fulfilled our criteria of ADPKD. There were 40 (71.4%) males and 16 (28.6%) females in our study. The mean age at the time of diagnosis of ADPKD was 47.0 +/- 14.5 years. Mean follow up period for all patients was 7.6 +/- 4.2 years. Most common form of presentation was hypertension in 38 (67.9%) patients. Kidneys were palpable in 33 (58.9%), liver in 16 (28.6%) and spleen in 6 patients (10.7%). Microscopic haematuria was observed in 38 (67.8%) patients while gross haematuria was present in 10 (17.9%) patients. The murmur of mitral valve prolapse was found in 10 patients on clinical examination which was later confirmed on transthoracic echocardiography (TEE). On MRI/MRA 2 (3.6%) patients each had berry aneurysm and AV malformations. Three patients (5.4%) received renal transplant and 19 (33.9%) patients were dialysis dependent at the end of study. A total 11 (20%) were lost to follow up. Two patients (3.5%) died during six years follow up. Male sex and uncontrolled hypertension were most important predictors of poor prognosis (p < 0.03 and < 0.048 respectively).

CONCLUSION

Pre-symptomatic patients with ADPKD should be monitored with blood pressure measurements and assessment of their renal function. The advantages of such monitoring include the ability to prevent or control infection and hypertension, to identify potential kidney donors from among the family, to offer advice on marriage and childbearing, and to provide prenatal diagnosis.

Compression of left inferior vena cava: a form of nutcracker syndrome

Left renal vein hypertension has been described in the literature as a cause of persistent hematuria. We report a case of nutcracker syndrome with hematuria involving the left inferior vena cava diagnosed with Doppler sonography and MRI.

Haematuria in patients with haemophilia and its influence on renal function and proteinuria

To investigate renal function in a group of patients with a history of haemophilia and haematuria. We reviewed 32 medical records of the patients with haemophilia and gross haematuria identified through a computerized haemophilia registry, from January 1993 to December 2004. In all patients but three (two refused to participate and one died) clinical and laboratory tests were performed by the nephrologist. One patient had chronic renal failure because of diabetic nephropathy. In two patients reduced renal function was detected by creatinine clearance measurements, and one of them had Duchenne muscular dystrophy. In four patients minimal proteinuria was diagnosed by the biuret method. Mild reduction in renal function of unknown cause was found in only one of the 29 patients tested.

Nutcracker syndrome due to left renal vein compression by an aberrant right renal artery

Classic nutcracker syndrome is caused by left renal vein compression between the superior mesenteric artery and aorta, leading to retrograde venous hypertension associated with such urinary abnormalities as hematuria or proteinuria. We describe a case of symptomatic nutcracker syndrome treated by means of stent placement in which hypertension in the left renal vein was caused by stenosis of this vein compressed by an aberrant right renal artery at a point closer to the inferior vena cava.

[Alport syndrome or progressive hereditary nephritis with hearing loss]

Alport syndrome is an inherited disorder characterized by progressive hematuric nephritis with structural defects of the glomerular basement membrane, and sensorineural deafness. Ocular abnormalities are frequently associated. The incidence is approximatively 1/5000. The renal disease is severe in male patients and should be responsible for 2% of end-stage renal failure. Alport syndrome is heterogeneous at the clinical and genetic levels. It occurs as a consequence of structural abnormalities in type IV collagen, the major constituent of basement membranes. Six genetically distinct chains of type IV collagen have been identified. Mutations in the COL4A5 gene located at Xq22, and encoding the alpha 5(IV) chain are responsible for X-linked Alport syndrome whereas COL4A3 or COL4A4 located "head to head" on chromosome 2 are involved in the rarer autosomal forms of the disease.

Effect of renal Doppler ultrasound on the detection of nutcracker syndrome in children with hematuria

To assess the detection rate of nutcracker syndrome in children with isolated hematuria, renal Doppler ultrasound examinations were routinely performed on 216 consecutive children (176 microscopic hematuria and 40 gross hematuria). Renal Doppler ultrasound was also performed on 32 healthy normal children. The peak velocity (PV) was measured at the hilar portion of the left renal vein (LRV) and at the LRV between the aorta and the superior mesenteric artery. The PV at the aortomesenteric portion (P=0.003) and the PV ratios of the LRV (P=0.003) were significantly higher in children with hematuria than in normal children, while the PV at the hilar portion was not different. If a PV ratio of the LRV of at least 4.1 (the cut-off level set at the mean +/-2 SD of the value for the normal children) was defined as abnormal, 72 cases (33.3%) in children with hematuria and no cases in normal children were diagnosed as having nutcracker syndrome. The prevalence of nutcracker syndrome is relatively high in children with isolated hematuria, and the inclusion of renal Doppler ultrasound as a screening examination has a substantial effect on the detection of nutcracker syndrome.

Evaluation of hematuria using the urinary albumin-to-total-protein ratio to differentiate glomerular and nonglomerular bleeding

BACKGROUND

Depending on the etiology and pathophysiology of hematuria, urinary bleeding is classified as glomerular hematuria or nonglomerular hematuria. Nephritis is usually detected by the presence of proteinuria, especially elevated albumin excretion. In this study, we report on the use of the urinary albumin-to-total-protein ratio to accurately differentiate glomerular and nonglomerular bleeding.

METHODS

A total of 143 fresh, random urine specimens demonstrating microscopic hematuria (5 or more red blood cells per high-power field) from patients with the source of the hematuria confirmed by histopathology and/or clinical criteria were included in the study.

RESULTS

Of the 143 specimens, 104 were from patients diagnosed with glomerular disease and 39 were from patients with nonglomerular disease. Corrected for urine concentration, the mean total-protein-to-creatinine (Cr) and albumin-to-Cr ratios in the glomerular disease group were 1.67 +/- 2.71 g/g Cr and 1.15 +/- 1.77 g/g Cr, respectively (P < 0.001). In the nonglomerular group, the mean total protein-to-Cr and albumin-to-Cr ratios were 0.19 +/- 0.23 g/g Cr and 0.05 +/- 0.06 g/g Cr, respectively (P < 0.001). However, considerable overlap in the ratios among glomerular and nonglomerular disease groups was observed. In contrast, the mean albumin-to-total protein ratios for glomerular and nonglomerular diseases were 0.72 +/- 0.10 and 0.35 +/- 0.17, respectively (P < 0.001). At a cutoff of 0.59, the albumin-to-total-protein ratio demonstrated a sensitivity of 97.1% (101 of 104 cases) in detecting glomerular disease.

CONCLUSIONS

The urinary albumin-to-total-protein ratio is potentially a useful index for the differentiation of glomerular and nonglomerular disease in the presence of microscopic hematuria.

Transverse Vaginal Septum with Congenital Vesical-Vaginal Communication and Cyclical Hematuria

Cyclical hematuria is an unusual presentation of a müllerian fusion anomaly. We report a patient with transverse vaginal septum and menstruation by way of the lower urinary tract because of a vesical-vaginal communication. A defect of vertical fusion, transverse vaginal septum results from failure of canalization of the vaginal plate. Reconstruction using a transvaginal and transabdominal approach created a direct anastomosis between the proximal vaginal segment and the distal vaginal pouch. Previously described cases are reviewed.

Factors that determine an incomplete recovery of renal function in macrohematuria-induced acute renal failure of IgA nephropathy

Acute renal failure that is associated with macroscopic hematuria (ARF-MH) is a widely known complication of IgA nephropathy (IgAN). Although spontaneous recovery of renal function after cessation of MH has been described, no long-term outcome studies have been performed. The outcome of patients who had biopsy-proven IgAN and presented an ARF-MH episode in the period 1975 through 2005 was studied. Thirty-six episodes of ARF-MH that occurred in 32 patients were identified. A complete recovery of baseline renal function after cessation of MH was observed in 27 (group 1); in the remaining nine episodes (25%; group 2), estimated GFR (eGFR) did not reach the baseline value. Final eGFR was 89 +/- 28 ml/min per 1.73 m(2) in group 1 patients and 38 +/- 12 ml/min per 1.73 m(2) in group 2 patients (P = 0.0005). The duration of MH was significantly longer in group 2 patients: 33.7 +/- 25.3 versus 15.4 +/- 18.4 d (P = 0008). A high proportion of tubules that were filled by red blood cell casts and had signs of acute tubular necrosis were the most striking histologic abnormalities. In conclusion, a significant proportion (25%) of ARF-MH in IgAN did not recover the baseline renal function after the disappearance of MH. Duration of MH longer than 10 d, age >50 yr, decreased baseline eGFR, absence of previous episodes of MH, and the severity of tubular necrosis were significant risk factors for an incomplete recovery of renal function.

Renal transplantation in a patient with loin pain hematuria syndrome

We describe a patient with loin pain hematuria syndrome who required bilateral nephrectomy because of intractable pain and urological complications. After bilateral nephrectomy, his pain disappeared for the first time in 40 years. He subsequently received a cadaveric renal transplant which, at 4-year follow-up, is working well. Although he has developed intermittent microscopic hematuria, there has been no significant recurrence of pain over the kidney. This is the first reported case of transplantation after bilateral nephrectomy for loin pain hematuria syndrome. It provides insight tnto the possible pathogenic mechanisms underlying the condition.

Hepatitis-B virus-associated nephropathies in adults: a clinical study in Thailand

Hepatitis B virus (HBV)-associated glomerulonephropathy (HBV-GN) has been increasingly reported, especially in adults. In the present study, the authors investigated the clinical and histopathology features of patients who suspected HBV-GN in 24 patients and age ranging from 23 to 74 years (mean 43 years). Asymptomatic hematuria was the most common presentation (54%); followed by edema and hypertension at equal percentages of 50%. The nephrotic syndrome was presented in 43%, the nephrito-nephrotic syndrome in 3.5%. Clinically suspected rapidly progressive GN was found in 14%. Renal insufficiency was determined in 30%. The most common pathologic finding was IgA nephropathy (IgAN 29%), followed by membranous nephropathy (21%), focal segmental glomerulo sclerosis (FSGS 11%), membranoproliferative GN (11%), post-infectious GN (11%). Liver disease activity also tended to be mild or had no symptoms of hepatitis. The authors remission rates both complete and partial were 75% (higher than the usual report), notwithstanding treatment. The authors achieved a sustained complete remission in half of the patients (3 in 6 cases) treated with steroid alone and 2 out of 7 cases (28.6%) treated with anti-viral therapy. Spontaneous remission was demonstrated in 2 (1 with IgAN + FSGS, and 1 with post infectious GN) out of 6 patients (33.3%). None of the patients in both treatment groups turned to ESRD that occurred in 2 cases receiving non-specific treatment. Of note, all of the patients who received anti-viral therapy or corticosteroid and had complete follow up were in remission either complete or partial.

Nutcracker syndrome in children with gross haematuria: Doppler sonographic evaluation of the left renal vein

BACKGROUND

Nutcracker syndrome is characterized by gross haematuria caused by left renal vein (LRV) entrapment.

OBJECTIVE

To assess the role of LRV ultrasonography in the diagnosis of the nutcracker syndrome in children.

MATERIALS AND METHODS

Twelve children (eight male, four female; mean age 12.8 years) with venographically confirmed nutcracker syndrome (LRV-IVC pressure gradient > or = 3 mm Hg) underwent LRV sonography including Doppler spectral analysis (n=7). The diameter and peak velocity (PV) were measured at two sites of the LRV (renal hilum and aortomesenteric portion). The US findings of nutcracker syndrome were compared with those of 20 control subjects using the t-test. We identified the optimal cut-off value of the US parameters for the diagnosis of the nutcracker syndrome using ROC analysis.

RESULTS

The PV at the aortomesenteric portion and the ratio of the PV between the two measured points showed significant differences between the two groups (P<0.0001). The optimum cut-off values were found to be 4.7 for the PV ratio (sensitivity 100%, specificity 90%, accuracy 93%), and 93 cm/s for the PV at the aortomesenteric portion (sensitivity 100%, specificity 85%, accuracy 89%).

CONCLUSION

LRV sonography, including Doppler spectral analysis, can demonstrate LRV entrapment haemodynamically.

Evaluation of the effects of stress in cats with idiopathic cystitis

OBJECTIVE

To determine the effects of stress in cats with feline idiopathic cystitis (FIC) by evaluating bladder permeability, sympathetic nervous system function, and urine cortisol:creatinine (C:Cr) ratios during periods of stress and after environmental enrichment.

DESIGN

Prospective study.

ANIMALS

13 cats with FIC and 12 healthy cats.

PROCEDURE

Cats subjected to an acute-onset moderate stressor for 8 days received IV injections of fluorescein. Serum fluorescein concentrations were determined and compared with those of controls to evaluate bladder permeability, and urine C:Cr ratios were compared to evaluate function of the hypothalamic-pituitary-adrenal (HPA) axis. Plasma catecholamine concentrations were analyzed in a subset of cats. After 8 days of moderate stress, cats were moved to an enriched environment, and tests were repeated after 21 days.

RESULTS

Serum fluorescein concentrations were significantly higher in cats with FIC at all time points. In the cats in which plasma catecholamine concentrations were determined, concentrations of dihydroxyphenylalanine, norepinephrine, and dihyroxyphenylglycol were significantly higher in cats with FIC at all time points, whereas no differences in urine C:Cr ratio between groups were observed.

CONCLUSION AND CLINICAL RELEVANCE

Cats with FIC appeared to have altered bladder permeability, most notably during the period of initial stress. The increase in plasma dihydroxyphenylalanine concentration suggests that there may be stress-induced increase in the activity of tyrosine hydroxylase, which catalyzes the rate-limiting step in catecholamine synthesis. In contrast, no effects of stress on C:Cr ratios were observed, which suggests there was dissociation between the sympathetic nervous system and HPA-axis responses to stress.

The Bell-Shaped Nitinol Prostatic Stent in the Treatment of Lower Urinary Tract Symptoms: Experience in 108 Patients

OBJECTIVES

To assess the efficacy, safety, and durability of the bell-shaped nitinol prostatic stent in the treatment of moderate to severe lower urinary tract symptoms caused by benign prostatic enlargement in otherwise healthy patients.

METHODS

Stents were inserted in an outpatient setting under local anaesthesia. Assessments included maximum urinary flow (Qmax), postvoid residual (PVR) urine volume, International Prostate Symptom Score (IPSS), including quality of life (QoL) item, at baseline and follow-up visits.

RESULTS

108 men were enrolled in the trial. Stents were successfully inserted in 97% of the patients. Spontaneous voiding was achieved in all patients. After one month Qmax (+3.7 ml/s), PVR (-99 ml), IPSS (-12) and QoL (-1.7) all showed statistically significant improvements compared to baseline. Substantial improvements, however, were maintained for only one to two months. The main complications were haematuria (19%), urge incontinence (22%), and migration (15%). The median indwelling time was 105 days. The main reason for removal of stents was worsening of symptoms, which might be attributable to the tilting of stents within the prostatic urethra, found upon removal.

CONCLUSIONS

Insertion of the bell-shaped nitinol prostatic stent temporarily improves voiding parameters and symptom scores. Because of the limited durability, however, the bell-shaped prostatic stent is not suitable for clinical practice.

Autosomal-dominant polycystic kidney disease in infancy and childhood: progression and outcome

BACKGROUND

The natural history of autosomal-dominant polycystic kidney disease (ADPKD) has not been well described in children and infants.

METHODS

The present study analyzed the characteristics of 46 ADPKD children diagnosed before 18 months of life (VEO) and 153 children diagnosed between 18 months of age and 18 years of age (non-VEO).

RESULTS

VEO children had more cysts and larger renal volumes than non-VEO children when adjusted for age. In both VEO and non-VEO children, the presence of signs or symptoms at the time of diagnosis as well as the presence of hematuria or proteinuria at the study visit were associated with larger renal volumes. Children diagnosed early (VEO) or diagnosed due to signs or symptoms were also more likely to have high blood pressure. Two VEO children and no non-VEO children reached end-stage renal disease during follow-up.

CONCLUSION

In contrast to many published case reports suggesting the occurrence of early end-stage renal disease in VEO children, the results of the present study were much more optimistic. Over 90% of the VEO children maintained preserved renal function well into childhood.

Factors affecting spontaneous resolution of hematuria in childhood nutcracker syndrome

To identify factors affecting spontaneous resolution of hematuria in children with nutcracker syndrome, 20 patients diagnosed as having nutcracker syndrome using renal Doppler ultrasound (US) were analyzed retrospectively. Sixteen patients had microscopic hematuria, and four had gross hematuria at presentation. The mean age was 10.6 years (range 2.5-14 years). All underwent a follow-up Doppler US examination after a mean period of 1.4 years (range 0.5-3.5 years) after the first US was performed, and height and weight were measured at the time of US. At the time of follow-up US, hematuria disappeared in 15 patients and improved in 3. The peak velocity (PV) ratios of the left renal vein (LRV) at the follow-up US decreased significantly when compared to the first US examination (7.74+/-2.64 vs 3.50+/-1.09, p<0.0001), and height (147.4+/-20.1 vs 152.3+/-18.8 cm) and weight (36.1+/-10.9 vs 42.3+/-12.7 kg) increased (p<0.0001). Changes in the PV ratios of the LRV correlated positively with changes in the PV at the aortomesenteric portion (r=0.569, p=0.009). Changes in the PV at the aortomesenteric portion correlated negatively with changes in body mass index (BMI) (r=-0.543, p=0.013). Although spontaneous resolution of hematuria in children with nutcracker syndrome is obscure, our findings suggest the increase in BMI may be a possible hemodynamic factor.

The Vicious Cycling: Bicycling Related Urogenital Disorders

PURPOSE

Bicycle riding is one of the most popular means of transportation, recreation, fitness and sports among millions of people of all ages who ride on road and off road, using a variety of bicycle types. It is also a readily available form of aerobic non-impact exercise with established cardiovascular beneficial effects. Bicycles are also a common source of significant injuries. This review focuses upon the specific bicycling related overuse injuries affecting the genitourinary tract.

MATERIALS AND METHODS

MEDLINE search of the literature on bicycling and genitourinary disorders was performed using multiple subject headings and additional keywords. The search yielded overall 62 pertinent articles. We focused primarily on the most prevalent related disorders such as pudendal nerve entrapment, erectile dysfunction and infertility. The potential effect of bicycling on serum PSA level was also discussed in depth in view of its recognized clinical importance. Infrequent disorders, which were reported sporadically, were still addressed, despite their rarity, for the comprehensiveness of this review.

RESULTS

The reported incidence of bicycling related urogenital symptoms varies considerably. The most common bicycling associated urogenital problems are nerve entrapment syndromes presenting as genitalia numbness, which is reported in 50-91% of the cyclists, followed by erectile dysfunction reported in 13-24%. Other less common symptoms include priapism, penile thrombosis, infertility, hematuria, torsion of spermatic cord, prostatitis, perineal nodular induration and elevated serum PSA, which are reported only sporadically.

CONCLUSIONS

Urologists should be aware that bicycling is a potential and not an infrequent cause of a variety of urological and andrological disorders caused by overuse injuries affecting the genitourinary system.

Development of immune-complex glomerulonephritis in athymic mice: T cells are not required for the genesis of glomerular injury

Chronic injection of dextran into normal mice elicits a glomerulonephritis (GN) that models IgA nephropathy (IgAN) in humans. Since athymic mice lack T cells but nonetheless develop antibodies to polysaccharide antigens such as dextran (DEX), we used athymic mice to study the role of T lymphocytes in the induction of this form of GN, independent of the role of T cells in antibody synthesis. Both mice given injections of diethylaminoethyl (DEAE)-DEX and uninjected mice had circulating IgM and IgA anti-DEX antibodies, which apparently arise as 'natural antibodies', but immune complex GN was observed only in the injected mice. All of 15 injected mice exhibited capillary staining for IgA and IgM; none of 12 control mice contained such IgA deposits and only one had capillary staining for IgM (both P<0.001). In addition, IgG and C3 were detected in injected but not control animals. By light microscopy, injected mice exhibited marked expansion of mesangial matrix relative to controls. Electron microscopy showed no glomerular abnormalities in control mice, whereas injected mice showed large organized fibrillar deposits principally in the mesangium. Hematuria and proteinuria were present in all 15 injected mice, but only one of 11 control mice showed hematuria or proteinuria (both P<0.001). These results indicate that chronic injection of DEAE-DEX into athymic mice generates the same clinical and histologic features of GN as in euthymic mice, suggesting that T cells are not necessary to promote GN in this model.

Kidneys and sports

With better understanding of the nature of renal disease and its treatment, many more adolescents are now allowed to participate in recreational and competitive sports. The positive physiologic and psychological effects of exercise are increasingly being appreciated in adolescents with chronic diseases. This article reviews relevant aspects of renal disease that have implications for sports participation by adolescents, including hematuria, proteinuria, hyponatremia, hypertension, solitary kidney, exercise-related acute renal failure, and chronic/end-stage renal disease. It also reviews the renal effects of creatine and protein supplementation in athletes.

Spontaneous remission of persistent severe hematuria in an adolescent with nutcracker syndrome: seven years' observation

A Japanese boy aged 14 years presented with gross hematuria associated with mild proteinuria and was diagnosed as having nutcracker syndrome. Magnetic resonance angiography (MRA) revealed significant compression of the left renal vein between the aorta and the superior mesenteric artery with collaterals. A percutaneous renal biopsy on the right kidney revealed no evidence of glomerular or interstitial changes with immune deposition. He was observed closely without any intervention thereafter. Although repeat MRA performed 4 years after our first observation disclosed the development of collateral veins, severe hematuria with an intermittent exacerbation remained unchanged. During the next 2 years, the hematuria completely subsided spontaneously. Although the etiology of spontaneous remission of the disease remains speculative, his good physical development (i.e., approximately 10 cm taller than his height at the onset) may change presumptive hemodynamic factors. These clinical observations suggest that a proportion of pubertal patients with nutcracker syndrome should be treated conservatively for a relatively long time.

Familial Mediterranean fever and glomerulonephritis and review of the literature

Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by recurrent and self-limited attacks of fever usually accompanied by polyserositis. Amyloidosis is its most common renal complication. A number of reports have shown vasculitic diseases such as polyarteritis nodosa and Henoch-Schönlein purpura affecting the kidney in FMF. Here we present a patient with FMF and membranoproliferative glomerulonephritis and analyze the data published on these two entities.