Albert Torras

Mspl identifies a biallelic polymorphism in the promoter region of the α2A‐adrenergic receptor gene

Candidate gene: An increased activity of the sympathetic nervous system has been suggested to play a role in the pathophysiology of essential hypertension ( EHT). However, plasma catecholamine levels are not increased in these patients. An increased density of a,,-adrenergic receptors (a,,-AR) has been reported in patients with EHT (Mores et al. 1990, Calls et al. 1995). The activation of these receptors by epinephrine or norepinephrine promotes peripheral vasoconstriction and salt and water retention. The human cc,,-AR gene is located at 10q23-q25. The complete nucleotide sequence of this gene (HUMADRA2R) has been previously published (Fraser et al. 1989), and two restriction fragment length polymorphisms (DraI and Bsu36I RFLPs) have been reported to date (Hoehe et al. 1988, Sun et al. 1992). A significant association between DraI RFLP and essential hypertension has been described (Lockette et al. 1995, Svetkey et al. 1996), although there is no general agreement on these findings.

Visceral Involvement of Dialysis Amyloidosis

Carpal tunnel syndrome, peripheral arthropathy, erosive spondyloarthropathy and lytic bone lesions have all been associated with dialysis amyloidosis. Recent studies indicate that beta 2-microglobulin is the major constituent protein in this new form of amyloidosis. Dialysis amyloidosis was reported to have a local rather than a systemic involvement, although its full extent is yet to be determined. We investigated 3 patients on maintenance hemodialysis with bilateral carpal tunnel syndrome and amyloid arthropathy and found amyloid depositions in several organs. These findings suggest that, in contrast to what had been thought previously, dialysis amyloidosis could have systemic as well as visceral distribution. The amyloid deposits found were resistant against potassium permanganate treatment and reacted with anti-human beta 2-microglobulin antibody.

Ocular and Auditory Toxicity in Hemodialyzed Patients Receiving Desferrioxamine

During an 18-month period of study 41 hemodialyzed patients receiving desferrioxamine (10-40 mg/kg BW/3 times weekly) for the first time were monitored for detection of audiovisual toxicity. 6 patients presented clinical symptoms of visual or auditory toxicity. Moreover, detailed ophthalmologic and audiologic studies disclosed abnormalities in 7 more asymptomatic patients. Visual toxicity was of retinal origin and was characterized by a tritan-type dyschromatopsy, sometimes associated with a loss of visual acuity and pigmentary retinal deposits. Auditory toxicity was characterized by a mid- to high-frequency neurosensorial hearing loss and the lesion was of the cochlear type. Desferrioxamine withdrawal resulted in a complete recovery of visual function in 1 patient and partial recovery in 3, and a complete reversal of hearing loss in 3 patients and partial recovery in 3. This toxicity appeared in patients receiving the higher doses of desferrioxamine or coincided with the normalization of ferritin or aluminium serum levels. The data indicate that audiovisual toxicity is not an infrequent complication in hemodialyzed patients receiving desferrioxamine. Periodical audiovisual monitoring should be performed on hemodialyzed patients receiving the drug in order to detect adverse effects as early as possible.

Henoch-Schönlein Purpura Complicating Staphylococcal Endocarditis in a Heroin Addict

A 21-year-old heroin addict with right-sided staphylococcal endocarditis developed skin purpura, abdominal pain, bloody diarrhea, proteinuria and microscopic hematuria. Skin biopsy showed leukocytoclastic vasculitis with IgA deposits in dermal vessels and renal biopsy disclosed proliferative glomerulonephritis with granular mesangial IgA and fibrinogen deposition. These features are typical of Henoch-Schönlein purpura. Symptoms abated spontaneously. Since the syndrome appeared during cloxacillin therapy, both this drug or the infectious disease itself could have triggered the immune response. Henoch-Schönlein purpura is a distinct clinical entity that can complicate the course of staphylococcal endocarditis.

Propoxyphene-Induced Hypoglycemia in a Patient with Chronic Renal Failure

A 36-year-old man with ankylosing spondylitis, amyloidosis and chronic renal failure on maintenance hemodialysis developed severe hypoglycemia while being treated with propoxyphene. Upon discontinuation of the drug blood glucose levels returned to normal and hypoglycemia did not recur. Simultaneously with hypoglycemia, plasma glucagon and growth hormone levels were appropriately raised and serum insulin levels were adequately suppressed, thus ruling out hyperinsulinemia as the cause of hypoglycemia. A review of the literature disclosed four similar cases of propoxyphene-induced hypoglycemia, two of them with renal dysfunction. Propoxyphene should be remembered as a potential cause of hypoglycemia, particularly in patients with renal failure.

Henoch-Schönlein Purpura and IgA Nephropathy in Father and Son

Considerable controversy exists as to whether Henoch-Schönlein purpura and Iga nephropathy are different clinical manifestations of the same disease or if, on the contrary, they are separate entities. We report on the development of Henoch-Schönlein purpura and IgA nephropathy in 2 members of the same family. Patient 1, a 63-year-old man, presented with purpura in the legs, abdominal pain, hematuria, renal failure and proteinuria. A biopsy of a purpuric skin lesion showed small-vessel vasculitis, and a renal biopsy showed diffuse proliferative glomerulonephritis with prominent IgA deposits, thus making the diagnosis of Henoch-Schönlein purpura. Serum IgA was increased. Patient 2, the 30-year-old son of patient 1, underwent renal biopsy for the investigation of microscopic hematuria and proteinuria. There was no history of skin rash, and serum creatinine was normal. A renal biopsy showed expansion of the mesangial matrix and marked IgA deposition. HLA typing confirmed that they shared a haplotype. HLA B35 or DR4 were absent. These results demonstrate that Henoch-Schönlein purpura and IgA nephropathy can possibly be genetically related and therefore support the notion that these two diseases probably share a common pathogenesis.

Treatment of mitomycin-C-associated hemolytic uremic syndrome with plasmapheresis

Hemolytic uremic syndrome (HUS) is a severe complication that has been associated with mitomycin C(MMC) therapy and is referred to be mostly unresponsive to treatment. In the last 2 years we have observed 3 patients affected by HUS associated with MMC therapy which were treated with plasmapheresis

Persistent Low C3 Levels Associated with Meningococcal Meningitis and Membranoproliferative Glomerulonephritis

Recurrent meningococcal meningitis is usually related to terminal complement factor deficiencies (C5-C8); however it is not frequent with isolated primary C3 deficiency. Similarly, membranoproliferative glomerulonephritis has been described in association with primary C3 deficiencies and the presence of C3 nephritic factor. We present a case of an 18-year-old woman with relapsing meningococcal meningitis in whom membranoproliferative glomerulonephritis and persistent low serum C3 levels were found. A detailed immunological study was performed, but no other abnormalities in the complement components were found. C3 Nef was also negative. Moreover, the familiar complement studies showed an asymptomatic C4 deficiency in her mother and borderline C3 levels in her sister. The presence of persistent low serum C3 levels in the absence of other immunological abnormalities suggests that this is the cause of the relapsing meningococcal infections and the glomerular disease of this patient. We suggest that a complement deficiency, including isolated C3 deficiency, should be ruled out in all cases of relapsing meningitis. Further, the possibility of glomerular disease should be carefully considered in these patients.

Silent Renal Microangiopathy after Mitomycin C Therapy

Mitomycin C (MMC) is an alkylating agent which has been associated with microangiopathic hemolytic anemia and acute renal failure, with an overall incidence between 2 and 10%. This complication can develop several months after the initiation of chemotherapy. Isolated renal impairment without overt microangiopathic hemolytic anemia, although reported, is less frequently documented. We describe a 63-year-old man who developed progressive renal failure without any evidence of hemolysis or thrombopenia 10 months after beginning chemotherapy with MMC and Ftorafur. A renal biopsy displayed features of microangiopathy. The patient required the institution of chronic hemodialysis. In conclusion, it is important to be aware of this indolent but severe renal complication in patients treated with MMC. Urinary parameters and renal function should be monitored over a long period for an early diagnosis.

Reversal of renal failure after revascularization in atheromatous renovascular disease

We report 2 patients with severe renal failure and hypertension secondary to atherosclerotic renovascular disease who required hemodialysis. Successful surgical revascularization in these patients resulted in the recovery of renal function (twice in a patient) and in controlling the blood pressure. These results indicate that in the presence of severe renal artery obstruction renal parenchyma may be preserved, while renal function is absent. We highlight the usefulness of preoperative renal arteriography for evaluation of the affected vessel and the demonstration of collateral circulation and the value of preoperative renal biopsy in the prediction of the viability of the kidney parenchyma.