Amyloid A amyloidosis on medullary sponge kidney in a 28-year-old male with gout: A case report and literature review.

Amyloidosis is a large group of diseases that occur through misfolding of extracellular proteins that accumulate in tissues and organs. Gout is the most common inflammatory arthritis worldwide and starts with the crystallization of uric acid within the joints and soft tissues. Although gouty arthritis is accompanied by inflammation, AA amyloidosis is rarely seen in patients with gout. Here we present a case of AA amyloidosis on the medullary sponge kidney in a 28-year-old man with gout. Our case had been diagnosed with gout 3 years previously, and his older brother was also diagnosed with early-onset gout. As a result of the hyperuricemic nephropathy clinic and familial history, a whole gene sequence analysis was performed on the HPRT1 gene and UMOD gene, but no pathogenic changes were detected. Renal ultrasound revealed a bilateral medullary sponge kidney and amyloidosis was detected in the renal needle biopsy performed for the etiology of proteinuria. In our literature review, we found 16 cases in which gout was accompanied by AA amyloidosis. We present a 17th case and compare it with the other 16 cases.

Urinary proteome in inherited nephrolithiasis.

In the last decades, proteomics has been largely applied to the Nephrology field, with the double aim to (1) elucidate the biological processes underlying renal diseases; (2) identify disease-specific biomarkers, predictor factors of therapeutic efficacy and prognostic factors of disease progression. Kidney stone disease, and in particular, inherited nephrolithiasis (INL) are not an exception. Given the multifactorial origin of these disorders, the combination of genomics and proteomics studies may complement each other, with the final objective to give a global and comprehensive mechanistic view. In this review, we summarize the results of recent proteomic studies which have expanded our knowledge about INL, focusing the attention on monogenic forms of nephrolithiasis (cystinuria, Dent's disease, Bartter syndrome, distal renal tubular acidosis and primary hyperoxaluria), on polygenic hypercalciuria and on medullary sponge kidney disease.

Medullary sponge kidney and Caroli's disease in a patient with stricture urethra: look for the hidden in presence of the apparent.

Caroli's disease is a rare congenital disorder with incidence rate of approximately 1 in 1 000 000 population. Renal anomalies which may be associated with Caroli's disease include medullary sponge kidney (MSK), cortical cysts, adult recessive polycystic kidney disease and rarely autosomal dominant polycystic kidney disease. Exact incidence of MSK in patients of Caroli's disease is not known. There are only a handful of reported cases of this association in literature. We hereby report a case of Caroli's disease with MSK with nephrocalcinosis. He presented to primary health centre with symptoms of urethral stricture due to lichen sclerosus et atrophicus and was managed with repeated co-axial dilatation but was never evaluated for underlying chronic renal insufficiency due to MSK. The thorough clinical examination and proper evaluation is important in patient of urethral stricture with underlying chronic renal insufficiency to avoid delayed diagnosis, management and related complications.

Proteomic-based research strategy identified laminin subunit alpha 2 as a potential urinary-specific biomarker for the medullary sponge kidney disease.

Medullary sponge kidney (MSK) disease, a rare kidney malformation featuring recurrent renal stones and nephrocalcinosis, continues to be diagnosed using expensive and time-consuming clinical/instrumental tests (mainly urography). Currently, no molecular diagnostic biomarkers are available. To identify such we employed a proteomic-based research strategy utilizing urine from 22 patients with MSK and 22 patients affected by idiopathic calcium nephrolithiasis (ICN) as controls. Notably, two patients with ICN presented cysts. In the discovery phase, the urine of 11 MSK and 10 controls, were randomly selected, processed, and analyzed by mass spectrometry. Subsequently, several statistical algorithms were undertaken to select the most discriminative proteins between the two study groups. ELISA, performed on the entire patients' cohort, was used to validate the proteomic results. After an initial statistical analysis, 249 and 396 proteins were identified exclusive for ICN and MSK, respectively. A Volcano plot and ROC analysis, performed to restrict the number of MSK-associated proteins, indicated that 328 and 44 proteins, respectively, were specific for MSK. Interestingly, 119 proteins were found to differentiate patients with cysts (all patients with MSK and the two ICN with renal cysts) from ICN without cysts. Eventually, 16 proteins were found to be common to three statistical methods with laminin subunit alpha 2 (LAMA-2) reaching the higher rank by a Support Vector Machine, a binary classification/prediction scheme. ELISA for LAMA-2 validated proteomic results. Thus, using high-throughput technology, our study identified a candidate MSK biomarker possibly employable in future for the early diagnosis of this disease.

Medullary sponge kidney.

PURPOSE OF REVIEW: After it was first described in 1939, medullary sponge kidney (MSK) received relatively little attention. This was because it was believed to have a low prevalence and because it was considered a benign condition. Studies in recent years have been changing these convictions however, hence the present review. RECENT FINDINGS: Insight has been obtained on the genetic basis of this disease, supporting the hypothesis that MSK is due to a disruption at the 'ureteric bud-metanephric mesenchyme' interface. This explains why so many tubular defects coexist in this disease, and particularly a distal tubular acidification defect of which the highly prevalent metabolic bone disease is one very important consequence. In addition to the typical clinical phenotype of recurrent stone disease, other clinical profiles have now been recognized, that is, an indolent, almost asymptomatic MSK, and a rare form characterized by intractable, excruciating pain. SUMMARY: Findings suggest the need for a more comprehensive clinical characterization of MSK patients. The genetic grounds for the condition warrant further investigation, and reliable methods are needed to diagnose MSK.

[A woman with urinary tract infections and flank pain]. / Een vrouw met urineweginfecties en flankpijn.

A 52-year-old woman presented with recurrent urinary tract infections and flank pain. Both an abdominal CT-scan and a plain abdominal X-ray showed bilateral nephrocalcinosis and a kidney stone in the left ureter. These findings are suggestive of medullary sponge kidneys.

Adult renal cystic disease: a genetic, biological, and developmental primer.

Renal cystic diseases in adults are a heterogeneous group of disorders characterized by the presence of multiple cysts in the kidneys. These diseases may be categorized as hereditary, acquired, or developmental on the basis of their pathogenesis. Hereditary conditions include autosomal dominant polycystic kidney disease, medullary cystic kidney disease, von Hippel-Lindau disease, and tuberous sclerosis. Acquired conditions include cystic kidney disease, which develops in patients with end-stage renal disease. Developmental cystic diseases of the adult kidney include localized renal cystic disease, multicystic dysplastic kidney, and medullary sponge kidney. In recent years, many molecular and cellular mechanisms involved in the pathogenesis of renal cystic diseases have been identified. Hereditary renal cystic diseases are characterized by genetic mutations that lead to defects in the structure and function of the primary cilia of renal tubular epithelial cells, abnormal proliferation of tubular epithelium, and increased fluid secretion, all of which ultimately result in the development of renal cysts. A better understanding of these pathophysiologic mechanisms is now providing the basis for the development of more targeted therapeutic drugs for some of these disorders. Cross-sectional imaging provides useful information for diagnosis, surveillance, prognostication, and evaluation of treatment response in renal cystic diseases.

Coexistence of medullary sponge kidney and renal AA amyloidosis in a patient with nephrotic range proteinuria.

We report a patient with medullary sponge kidney (MSK) who presented with hematuria and nephrotic-range proteinuria. Renal biopsy revealed a diagnosis of renal AA amyloidosis. No secondary factors contributing to renal amyloidosis were demonstrated. To the best of our knowledge, this is the first reported case that demonstrates the coexistence of MSK and renal AA amyloidosis.

Coexistence of medullary sponge kidney and ulcerative colitis in the same patient: long-term follow-up.

We describe a female patient with ulcerative colitis since the age of 17, who was accidentally diagnosed as having medullary sponge kidney 3 years after the establishment of diagnosis of inflammatory bowel disease. The diagnosis of renal disease was based on the typical appearance of both kidneys on abdominal ultrasound examination and on IV pyelography findings. All other well-known causes of medullary sponge kidney were excluded on the basis of the relevant laboratory investigation. So far, the patient experienced only one episode of urinary infection but no renal colic. Since the time of diagnosis of ulcerative colitis her renal function tests are perfectly normal. She is under maintenance treatment with mesalazine. The benign nature of the situation was explained to her. She was advised to drink at least one and a half litter of water daily, in order to reduce the risk of nephrolithiasis. The combination of the two disorders in our patient is probably the result of a chance. However, taking into account the potentially dangerous long-term results of medullary sponge kidney, we suggest that patients with ulcerative colitis must have a careful ultrasound examination of both kidneys at least at the time of diagnosis of the bowel disease, in order to exclude the possibility of medullary sponge kidney, as conservative measures could result in avoidance of potentially dangerous complications, such as renal stones and urinary infections.

Medullary sponge kidney and urinary calculi: aeromedical concerns.

Medullary sponge kidney (MSK) is a benign disorder associated with a lifetime risk of renal stones in 60% of patients. Patients frequently have episodic painless hematuria, but are often otherwise asymptomatic unless renal calculi or infections complicate the disease. Nephrolithiasis is a relative, but frequently enforced, contraindication to space or other high-performance flight. Two case reports of asymptomatic NASA flight crew with MSK and three cases of United States Air Force (USAF) military aviators diagnosed with MSK are reviewed. All cases resulted in waiver and return to flight status after treatment and a vigorous followup and prophylaxis protocol. MSK in aviation and spaceflight necessitates case-by-case evaluation and treatment to rule out other potential confounding factors that might also contribute to stone formation and in order to requalify the aviator for flight duties.

Rabson-Mendenhall syndrome: medullary sponge kidney, a new component.

Rabson-Mendenhall syndrome is a rare genetic disorder characterized by severe insulin resistance, extreme hyperinsulinemia, postprandial hyperglycemia, growth retardation, and dysmorphisms. Enlargement of the kidneys and nephrocalcinosis have been described previously. We report a 10-year-old boy who presented with gross hematuria, unilateral hydronephrosis, and the initial diagnosis of bilateral extensive medullary nephrocalcinosis. Medullary sponge kidney (MSK) was included in the differential diagnosis given the ultrasound findings. Further evaluation by intravenous pyelogram confirmed the suspected bilateral MSK. Given the patient's history of hydronephrosis due to an obstructing renal stone and MSK, urine calcium excretion was assessed and found to be markedly increased at 9.5 mg/kg per day. To our knowledge, this is the first report of Rabson-Mendenhall syndrome and an association with MSK. We recommend evaluation for nephrocalcinosis, MSK, and hypercalciuria in all children diagnosed with Rabson-Mendenhall syndrome.

Medullary sponge kidney (Lenarduzzi-Cacchi-Ricci disease): a Padua Medical School discovery in the 1930s.

The introduction of radiological contrast media and intravenous (i.v.) urography in clinical diagnostics in the 1930s enabled the discovery of several diseases, including the medullary sponge kidney (MSK). MSK is a renal malformation characterized by cystic anomalies of precalyceal ducts, which is frequently associated with nephrocalcinosis and renal stones. Although it was first recognized by G Lenarduzzi in 1939, its thorough description was the result of the ante litteram multidisciplinary cooperation between a radiologist (Lenarduzzi), a urologist (Cacchi), and a pathologist (Ricci), all at the Padua University Hospital. These authors 'established' the paradigm for its diagnosis that is still used today. I.v. urography is the gold standard for the diagnosis of MSK, but as the technique is used less and less, there is a concrete possibility of this renal condition being forgotten in the future. Although the pathogenesis of MSK has yet to be elucidated, its association with different malformative conditions supports the idea that it is a developmental disorder. Recent findings suggest that MSK may be the consequence of a disruption of the ureteral-bud/metanephric-blastema interface.