Maine Coon renal screening: ultrasonographical characterisation and preliminary genetic analysis for common genes in cats with renal cysts.

The objective of this study was to assess the prevalence of renal cysts and other renal abnormalities in purebred Maine Coon cats, and to characterise these through genetic typing. Voluntary pre-breeding screening programmes for polycystic kidney disease (PKD) are offered for this breed throughout Switzerland, Germany and other northern European countries. We performed a retrospective evaluation of Maine Coon screening for renal disease at one institution over an 8-year period. Renal ultrasonography was performed in 187 healthy Maine Coon cats. Renal changes were observed in 27 of these cats. Renal cysts were found in seven cats, and were mostly single and unilateral (6/7, 85.7%), small (mean 3.6 mm) and located at the corticomedullary junction (4/6, 66.7%). Sonographical changes indicating chronic kidney disease (CKD) were observed in 10/187 (5.3%) cats and changes of unknown significance were documented in 11/187 (5.9%) cats. All six cats genetically tested for PKD1 were negative for the mutation, and gene sequencing of these cats did not demonstrate any common genetic sequences. Cystic renal disease occurs with a low prevalence in Maine Coons and is unrelated to the PKD observed in Persians and related breeds. Ultrasonographical findings compatible with CKD are not uncommon in juvenile Maine Coons.

Scleroderma Renal Crisis: A Rare but Severe Complication of Systemic Sclerosis

Scleroderma renal crisis (SRC) is a major complication in patients with systemic sclerosis (SSc). It is characterized by malignant hypertension and oligo/anuric acute renal failure. SRC occurs in 5% of patients with SSc, particularly in the first years of disease evolution and in the diffuse form. The occurrence of SRC is more common in patients treated with glucocorticoids, the risk increasing with increasing dose. Left ventricular insufficiency and hypertensive encephalopathy are typical clinical features. Thrombotic microangiopathy is detected in 43% of the cases. Anti-RNA-polymerase III antibodies are present in one third of patients who develop SRC. Renal biopsy is not necessary if SRC presents with classical features. However, it can help to define prognosis and guide treatment in atypical forms. The prognosis of SRC has dramatically improved with the introduction of angiotensin-converting enzyme inhibitors (ACEi). However, 5 years survival in SSc patients who develop the full picture of SRC remains low (65%). SRC is often triggered by nephrotoxic drugs and/or intravascular volume depletion. The treatment of SRC relies on aggressive control of blood pressure with ACEi, if needed in combination with other types of antihypertensive drugs. Dialysis is frequently indicated, but can be stopped in approximately half of patients, mainly in those for whom a perfect control of blood pressure is obtained. Patients who need dialysis for more than 2 years qualify for renal transplantation.

Eculizumab in atypical hemolytic uremic syndrome: long-term clinical course and histological findings

Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy associated with defective regulation of the alternative complement pathway. The prognosis for patients with aHUS is poor, and plasma exchange represents the first-line therapy. Eculizumab is a humanized monoclonal anti-C5 antibody that prevents the activation of the terminal complement pathway. Here, we report the case of a 9-year-old girl with frequent relapsing aHUS due to heterozygous factor H mutation who was initially treated with plasma exchange three times per week with 150% plasma exchange volume. This treatment frequently caused allergic reactions and school absences. Because any reduction in the frequency of plasma exchange immediately induced relapses of the aHUS, treatment with eculizumab, 600 mg every 2 weeks, was started and plasma exchange completely stopped. On this drug regimen the patient showed no evidence of disease activity during a period of more than 24 months. Renal function improved, proteinuria disappeared, the number of antihypertensive medications could be decreased, and the quality of life increased substantially. The inhibition of the terminal complement pathway by eculizumab was also confirmed by renal biopsy, which showed the absence of thrombotic microangiopathy 2 months after the initiation of eculizumab therapy. This case illustrates the long-term favorable outcome of aHUS with eculizumab treatment.

[Glomerulonephritis and vasculitis as causes of arterial hypertension]

The various types of glomerulonephritis, including many forms of vasculitis, are responsible for about 15% of cases of end-stage renal disease (ESRD). Arterial hypertension represents a frequent finding in patients suffering from glomerulonephritis or vasculitis and hypertension also serves as an indicator for these severe types of diseases. In addition, there are symptoms and signs like hematuria, proteinuria and renal failure. Especially, rapidly progressive glomerulonephritis (RPGN) constitutes a medical emergency and must not be missed by treating physicians. This disease can either occur limited to the kidneys or in the context of a systemic inflammatory disorder, like a vasculitis. If left untreated, RPGN can lead to a necrotizing destruction of glomeruli causing irreversible kidney damage within several months or even weeks. With respect to the immunologically caused vasculitis, there are - depending upon the severity and type of organ involved - many clinical warning signs to be recognized, such as arterial hypertension, hemoptysis, arthalgias, muscle pain, palpable purpura, hematuria, proteinuria and renal failure. In addition, constitutional signs, such as fever and loss of body weight may occur concurrently. Investigations of glomerulonephritis or vasculitis must contain a careful and complete examination of family history and medications used by the respective patient. Thereafter, a thorough clinical examination must follow, including skin, joints and measurement of arterial blood pressure. In addition, a spectrum of laboratory analyses is required in blood, such as full blood screen, erythrocyte sedimentation rate, CRP, creatinine, urea and glucose, and in urine, including urinalysis looking for hematuria, red cell casts and proteinuria. Importantly, proteinuria needs to be quantified by the utilization of a random urine sample. Proteinuria > 3g/d is diagnostic for a glomerular damage. These basic tests are usually followed by more specialized analyses, such as a screening for infections, including search for HIV, hepatitis B or C and various bacteria, and for systemic inflammatory diseases, including tests for antibodies, such as ANA, anti-dsDNA, ANCA, anti-GBM and anti-CCP. In cases of membranous nephropathy, antibodies against phospholipase-A2-receptor need to be looked for. Depending upon the given clinical circumstances and the type of disease, a reasonable tumor screening must be performed, especially in cases of membranous and minimal-change nephropathy. Finally, radiological examinations will complete the initial work-up. In most cases, at least an ultrasound of the kidney is mandatory. Thereafter, in most cases a renal biopsy is required to establish a firm diagnosis to define all treatment options and their chance of success. The elimination of a specific cause for a given glomerulonephritis or vasculitis, such as an infection, a malignancy or a drug-related side-effect, remains the key principle in the management of these diseases. ACE-inhibitors, angiotensin receptor-blockers, aldosteron antagonists and renin-inhibitors remain the mainstay in the therapy of arterial hypertension with proteinuria. Only in cases of persistently high proteinuria, ACE-inhibitors and angiotensin receptor blockers can be prescribed in combination. Certain types of glomerulonephritis and essentially all forms of vasculitis require some form of more specific anti-inflammatory therapy. Respective immunosuppressive drug regimens contain traditionally medications, such as glucocorticoids (e. g. prednisone), cyclosporine A, mycophenolate mofetil, cyclophosphamide, and azathioprine. With respect to more severe forms of glomerulonephritis and vasculitis, the antibody rituximab represents a new and less toxic alternative to cyclophosphamide. Finally, in certain special cases, like Goodpasture's syndrome or severe ANCA-positive vasculitis, a plasma exchange will be useful and even required.

Antegrade endopyelotomy for treatment of ureteropelvic junction obstruction in transplanted kidneys

BACKGROUND AND PURPOSE: Little is known about the incidence and treatment of ureteropelvic junction (UPJ) obstruction of renal grafts. We report on three cases treated by endopyelotomy. PATIENTS AND METHODS: Graft function declined in three patients 98, 135, and 144 days after kidney transplantation. Acute rejection was excluded by renal biopsy. Ultrasonography revealed a dilated collecting system, and a percutaneous nephrostomy tube was placed. An antegrade nephrostogram showed UPJ obstruction. Percutaneous antegrade endopyelotomy was performed with the cold-knife technique, and the area was stented for 6 weeks using a 14F/8.2F Smith endopyelotomy stent. RESULTS: No intraoperative or postoperative complications occurred. The endopyelotomies were successful, and the creatinine clearances returned to normal. CONCLUSION: Antegrade endopyelotomy in patients with UPJ obstruction of a renal graft is feasible and effective. Normal kidney function was restored after correction of the obstruction.

Uromodulin is expressed in renal primary cilia and UMOD mutations result in decreased ciliary uromodulin expression

Uromodulin (UMOD) mutations are responsible for three autosomal dominant tubulo-interstitial nephropathies including medullary cystic kidney disease type 2 (MCKD2), familial juvenile hyperuricemic nephropathy and glomerulocystic kidney disease. Symptoms include renal salt wasting, hyperuricemia, gout, hypertension and end-stage renal disease. MCKD is part of the 'nephronophthisis-MCKD complex', a group of cystic kidney diseases. Both disorders have an indistinguishable histology and renal cysts are observed in either. For most genes mutated in cystic kidney disease, their proteins are expressed in the primary cilia/basal body complex. We identified seven novel UMOD mutations and were interested if UMOD protein was expressed in the primary renal cilia of human renal biopsies and if mutant UMOD would show a different expression pattern compared with that seen in control individuals. We demonstrate that UMOD is expressed in the primary cilia of renal tubules, using immunofluorescent studies in human kidney biopsy samples. The number of UMOD-positive primary cilia in UMOD patients is significantly decreased when compared with control samples. Additional immunofluorescence studies confirm ciliary expression of UMOD in cell culture. Ciliary expression of UMOD is also confirmed by electron microscopy. UMOD localization at the mitotic spindle poles and colocalization with other ciliary proteins such as nephrocystin-1 and kinesin family member 3A is demonstrated. Our data add UMOD to the group of proteins expressed in primary cilia, where mutations of the gene lead to cystic kidney disease.

Correlation of serum and urinary matrix metalloproteases/tissue inhibitors of metalloproteases with subclinical allograft fibrosis in renal transplantation

Progressive interstitial fibrosis and tubular atrophy (IF/TA) is a leading cause of chronic allograft dysfunction. Increased extracellular matrix remodeling regulated by matrix metalloproteases (MMPs) and their inhibitors (TIMPs) has been implicated in the development of IF/TA. The aim of this study was to investigate whether urinary/serum MMPs/TIMPs correlate with subclinical IF/TA detected in surveillance biopsies within the first 6months post-transplant. We measured eight different MMPs/TIMPs simultaneously in urine and serum samples from patients classified as normal histology (n=15), IF/TA 1 (n=15) and IF/TA 2-3 (n=10). There was no difference in urinary MMPs/TIMPs among the three groups, and only 1/8 serum MMPs/TIMPs (i.e. MMP-1) was significantly elevated in biopsies with IF/TA 2-3 (p=0.01). In addition, urinary/serum MMPs/TIMPs were not different between surveillance biopsies demonstrating an early development of IF/TA (i.e. delta IF/TA≥1 compared to a previous biopsy obtained three months before; n=11) and stable grade of IF/TA (i.e. delta IF/TA=0; n=20). Next, we investigated whether urinary/serum MMP/TIMP levels are elevated during acute subclinical tubulitis in surveillance biopsies obtained within the first 6months post-transplant (n=25). Compared to biopsies with normal histology, serum MMPs/TIMPs were not different; however, all urinary MMP/TIMP levels were numerically higher during subclinical tubulitis (MMP-1, MMP-7, TIMP-1 with p≤0.04). We conclude that urinary/serum MMPs/TIMPs do hardly correlate with existing or early developing IF/TA in surveillance biopsies obtained within the first 6months post-transplant. This could be explained by the dynamic process of extracellular matrix remodeling, which seems to be active during acute tubulo-interstitial injury/inflammation, but not in quiescent IF/TA.

Early renal failure after domino hepatic transplantation using the liver from a compound heterozygous patient with primary hyperoxaluria.

BACKGROUND To cover the shortage of cadaveric organs, new approaches to expand the donor pool are needed. Here we report on a case of domino liver transplantation (DLT) using an organ harvested from a compound heterozygous patient with primary hyperoxaluria (PHO), who underwent combined liver and kidney transplantation. The DLT recipient developed early renal failure with oxaluria. The time to the progression to oxalosis with renal failure in such situations is unknown, but, based on animal data, we hypothesize that calcineurin inhibitors may play a detrimental role. METHODS A cadaveric liver and kidney transplantation was performed in a 52-year-old male with PHO. His liver was used for a 64-year-old patient with a non-resectable, but limited cholangiocarcinoma. RESULTS While the course of the PHO donor was uneventful, in the DLT recipient early post-operative, dialysis-dependent renal failure with hyperoxaluria developed. Histology of a kidney biopsy revealed massive calcium oxalate crystal deposition as the leading aetiological cause. CONCLUSIONS DLT using PHO organs for marginal recipients represents a possible therapeutic approach regarding graft function of the liver. However, it may negatively alter the renal outcome of the recipient in an unpredictable manner, especially with concomitant use of cyclosporin. Therefore, we suggest that, although DLT should be promoted, PHO organs are better excluded from such procedures.

Cardiovascular-renal axis disorders in the domestic dog and cat: a veterinary consensus statement.

OBJECTIVES There is a growing understanding of the complexity of interplay between renal and cardiovascular systems in both health and disease. The medical profession has adopted the term "cardiorenal syndrome" (CRS) to describe the pathophysiological relationship between the kidney and heart in disease. CRS has yet to be formally defined and described by the veterinary profession and its existence and importance in dogs and cats warrant investigation. The CRS Consensus Group, comprising nine veterinary cardiologists and seven nephrologists from Europe and North America, sought to achieve consensus around the definition, pathophysiology, diagnosis and management of dogs and cats with "cardiovascular-renal disorders" (CvRD). To this end, the Delphi formal methodology for defining/building consensus and defining guidelines was utilised. METHODS Following a literature review, 13 candidate statements regarding CvRD in dogs and cats were tested for consensus, using a modified Delphi method. As a new area of interest, well-designed studies, specific to CRS/CvRD, are lacking, particularly in dogs and cats. Hence, while scientific justification of all the recommendations was sought and used when available, recommendations were largely reliant on theory, expert opinion, small clinical studies and extrapolation from data derived from other species. RESULTS Of the 13 statements, 11 achieved consensus and 2 did not. The modified Delphi approach worked well to achieve consensus in an objective manner and to develop initial guidelines for CvRD. DISCUSSION The resultant manuscript describes consensus statements for the definition, classification, diagnosis and management strategies for veterinary patients with CvRD, with an emphasis on the pathological interplay between the two organ systems. By formulating consensus statements regarding CvRD in veterinary medicine, the authors hope to stimulate interest in and advancement of the understanding and management of CvRD in dogs and cats. The use of a formalised method for consensus and guideline development should be considered for other topics in veterinary medicine.

Post mortem computed tomography and core needle biopsy in comparison to autopsy in eleven bernese mountain Dogs with histiocytic sarcoma

Background: Bernese mountain dogs are reported to have a shorter life expectancy than other breeds. A Major reason for this has been assigned to a high tumour prevalence, especially of histiocytic sarcoma. The efforts made by the breeding clubs to improve the longevity with the help of genetic tests and breeding value estimations are impeded by insufficiently reliable diagnoses regarding the cause of death. The current standard for post mortem examination in animals is performance of an autopsy. In human forensic medicine, imaging modalities, such as computed tomography and magnetic resonance imaging, are used with increasing frequency as a complement to autopsy. The present study investigates, whether post mortem computed tomography in combination with core needle biopsy is able to provide a definitive diagnosis of histiocytic sarcoma. For this purpose we have analysed the results of post mortem computed tomography and core needle biopsy in eleven Bernese mountain dogs. In the subsequent autopsy, every dog had a definitive diagnosis of histiocytic sarcoma, based on immunohistochemistry. Results: Computed tomography revealed space-occupying lesions in all dogs. Lesion detection by post mortem computed tomography was similar to lesion detection in autopsy for lung tissue (9 cases in computed tomography / 8 cases in autopsy), thoracic lymph nodes (9/8), spleen (6/7), kidney (2/2) and bone (3/3). Hepatic nodules, however, were difficult to detect with our scanning protocol (2/7). Histology of the core needle biopsies provided definitive diagnoses of histiocytic sarcoma in ten dogs, including confirmation by immunohistochemistry in six dogs. The biopsy samples of the remaining dog did not contain any identifiable neoplastic cells. Autolysis was the main reason for uncertain histological diagnoses. Conclusions: Post mortem computed tomography is a fast and effective method for the detection of lesions suspicious for histiocytic sarcoma in pulmonary, thoracic lymphatic, splenic, osseous and renal tissue. Optimization of the procedure regarding the scanning protocol and tissue sample size and number will improve the accuracy of the method. Keywords: Post mortem computed tomography, Core needle biopsy, Bernese mountain dog, Histiocytic sarcoma, Autopsy