Osvaldo Merege Vieira Neto

Star fruit: simultaneous neurotoxic and nephrotoxic effects in people with previously normal renal function

Patients with renal failure not yet on dialysis (stages 3–5) or on dialysis treatment are susceptible to intoxication from eating star fruit (Figure ​(Figure1).1). In these patients, star fruit may cause mild to severe neurotoxicity including hiccups, vomiting, asthenia, mental confusion, seizures, coma and death [1–3]. However, there are anecdotal reports of individuals with normal renal function who became intoxicated as a result of eating or drinking a large amount of star fruit, and intractable and persistent hiccups are usually the main symptom. Fig. 1 Star fruit (Averrhoa carambola) or carambola has been cultivated in Malaysia, Southern China, Taiwan, India and Brazil. It is rather popular in the Philippines and Queensland, Australia and moderately so in some of the South Pacific Islands, particularly ... Star fruit nephrotoxicity in people with normal renal function is rarely reported and it is never associated with signs of neurotoxicity. There is only prior one study of such cases, which reported on two cases of acute renal failure (ARF) due to acute oxalate nephropathy in patients with previous normal renal function [4]. In the current study, we present five patients with previously normal renal function who became intoxicated from eating star fruit or drinking star fruit juice and presented simultaneously nephrotoxic and neurotoxic effects.

Doenças renais em pacientes idosos submetidos à biópsia percutânea de rins nativos

INTRODUCTION: The elderly population is growing and aging in better clinical conditions than in the past. However, the distribution and course of kidney diseases in elderly patients are not well known partially due to reluctance to indicate renal biopsies in those patients. OBJECTIVE: To evaluate the distribution, clinical features, and outcomes of nephropathies diagnosed by biopsy in the elderly. PATIENTS AND METHODS: Seventyone patients (47 males, 24 females) aged 60 years or older (67.3 ± 6.5 years), undergoing biopsy from January 1990 to December 2006, were evaluated. They were grouped according to their clinical syndromes. RESULTS: Nephrotic syndrome was observed in 35 patients (49.3%), mainly associated with membranous nephropathy (17 patients), followed by amyloidosis and focal segmental glomerulosclerosis (seven patients each). Acute kidney injury (AKI) was diagnosed in 19 patients, and the main histopathological diagnoses were acute tubular necrosis (six patients) and cast nephropathy (three patients). Of those 19 patients, only two had a favorable course, while the others died early or progressed toward advanced chronic kidney disease. Twelve patients undergoing biopsy because of asymptomatic hematuria or proteinuria had different diagnoses, but most of them already had significant chronic nephropathy. In five patients with nephritic syndrome, the biopsies also showed several diagnoses. CONCLUSIONS: Nephrotic syndrome was the major indication for renal biopsy, and membranous nephropathy was the most frequent diagnosis. Among patients with AKI and asymptomatic hematuria or proteinuria, different diagnoses were found with high levels of advanced chronic nephropathy.

Urinary Excretion of Monocyte Chemoattractant Protein-1: A Biomarker of Active Tubulointerstitial Damage in Patients with Glomerulopathies

Background/Aims: The urinary concentration of the monocyte chemoattractant protein-1 (uMCP-1) chemokine is increased in several proteinuric and/or inflammatory renal diseases. In the present study, we evaluated the association between uMCP-1 and renal function, proteinuria, glomerular and interstitial macrophage infiltration, and renal fibrosis in patients with primary and secondary glomerulopathies diagnosed by renal biopsy. Methods: Thirty-seven patients aged 32.6 ± 7.7 years were studied. uMCP-1 was determined by ELISA. Renal macrophage expression (CD68 positive cells) is reported as number of macrophages/104 µm2 of the cortical tubulointerstitial (TI) area or of glomerular capillary tuft area. Cortical interstitial fibrosis was quantitated by PicroSirius red staining under polarized light by a computerized manner. Results: The uMCP-1 ratio (pg/ml/urinary creatinine mg/ml) was positively correlated (Spearman coefficient) with proteinuria (r = 0.4629; p < 0.005) and number of macrophages in the cortical TI area (r = 0.64; p = 0.0005), and negatively correlated with creatinine clearance (r = –0.4877; p < 0.001). The uMCP-1 ratio was not significantly correlated with number of macrophages/glomerular capillary tuft area (r = 0.27; p = 0.19) or with percent cortical interstitial fibrosis (r = 0.08; p = 0.62). Conclusions: The uMCP-1 excretion is a biomarker of the inflammatory activity of the TI area, and does not reflect chronic interstitial damage.

Minimal change disease: a variant of lupus nephritis

Some patients with systemic lupus erythematosus (SLE) present with nephrotic syndrome due to minimal change disease (MCD). Histopathological diagnosis of patients with SLE and nephrotic-range proteinuria has shown that these patients present with diffuse proliferative glomerulonephritis and membranous glomerulonephritis, World Health Organization (WHO) classes IV and V, respectively, more frequently than the other classes. In the present study, we reported a case of nephrotic syndrome and renal biopsy-proven MCD associated with SLE. A complete remission occurred after steroid treatment, which was followed by a relapse 15 months later with a concomitant reactivation of SLE. A second biopsy showed WHO class IIb lupus nephritis. Prednisone treatment was restarted, and the patient went into complete remission again. The association of MCD and SLE may not be a coincidence, and MCD should be considered as an associated SLE nephropathy.

Membranous glomerulonephritis associated with splenic marginal zone lymphoma mimicking multiple myeloma.

Glomerulonephritis may complicate the course of a wide variety of malignant diseases. However, there are relatively few reports of membranous glomerulonephritis (MGN) in patients with non-Hodgkin lymphoma (NHL). We describe for the first time a case of MGN associated with splenic marginal zone lymphoma with extreme plasmacytic differentiation and bone marrow infiltration mimicking multiple myeloma. We also reviewed the literature and summarize the clinical-pathological findings and the mechanisms involved in NHL-induced MGN. Our current case highlights the importance of a quick and correct diagnosis of the underlying disease and the value of a thorough physical examination. Clinicians should be aware of the possibility of an underlying hematologic malignancy in such cases, particularly in elderly patients with renal biopsy that shows the presence of atypical histology.

Effect of the Absence of Interleukin-12 on Mesangial Proliferative Glomerulonephritis Induced by Habu Snake Venom

Background. Interleukin-12 (IL12) participates in the pathophysiology of various experimental types of progressive glomerulonephritis, but its role in acute mesangial glomerulonephritis (AMG) induced by habu snake venom (HSV) has not been determined. This study aims to evaluate the effect of the absence of IL12 on AMG induced by HSV. Methods. AMG was induced in IL12 knockout (IL12–/–) and C57Bl/6 (IL12+/+) mice by a single i.v. administration of HSV. Vehicle was used in control animals. Mice were studied after 3, 7, and 14 days (D3, D7, and D14). Results. After treatment with HSV, IL12+/+ and –/– mice developed focal glomerular lesions, but groups of both lineages showed no statistical difference concerning albuminuria, serum creatinine, histopathology, number of cells by glomerular tuft, and glomerular tuft area. Compared to IL12+/+ mice, IL12–/– mice showed lower scores of glomerular desmin expression on D7 [1.55 (1.32; 1.65) vs. 1.12 (1.07; 1.22); p < 0.01] and D14 [1.60 (1.55; 1.75) vs. 1.20 (1.15; 1.20); p < 0.001], respectively, and lower scores of glomerular α-SMA expression on D14 [0.30 (0.21; 0.38) vs. 0.16 (0.26; 0.36); p < 0.001], respectively. Conclusion. The absence of IL12 reduced the activity of mesangial cells, but did not modify the course of HSV-induced AMG in mice.

Resposta à corticoterapia na nefropatia da IgA primária

resumo DOI: 10.5935/01012800.20130005

Corticotherapy response in primary IgA nephropathy

INTRODUCTION Some beneficial effects from long-term use of corticosteroids have been reported in patients with IgA nephropathy. OBJECTIVE This retrospective study aimed to evaluate the outcome of proteinuria and renal function according to a protocol based on a 6-month course of steroid treatment. METHOD Twelve patients were treated with 1 g/day intravenous methylprednisolone for 3 consecutive days at the beginning of months 1, 3, and 5 plus 0.5 mg/kg oral prednisone on alternate days for 6 months (treated group). The control group included 9 untreated patients. RESULTS Proteinuria (median and 25th and 75th percentiles) at baseline in the treated group was 1861 mg/24h (1518; 2417 mg/24h) and was 703 mg/24h (245; 983) and 684 mg/24h (266; 1023) at the 6th (p < 0.05 vs. baseline) and 12th months (p < 0.05 vs. baseline), respectively. In the control group the proteinuria was 1900 mg/24h (1620; 3197) at baseline and was 2290 mg/24h (1500; 2975) and 1600 mg/24h (1180; 2395) at the 6th and 12th months, respectively (not significant vs. baseline). When compared with the control group, the treated group showed lower proteinuria (p < 0.05) during the follow-up and a higher number of patients in remission (p < 0.05) at the 6th and 12th months. Renal function did not change during the follow-up and the adverse effects were mild in most of the patients. CONCLUSION The 6-month course of steroid treatment was effective in reducing proteinuria during the 12 months of the follow-up, and was well-tolerated by most of the patients.

Minimal change disease associated with type 1 and type 2 diabetes mellitus

A 19-year-old female with type 1 diabetes for four years, and a 73-year-old female with type 2 diabetes for twenty years developed sudden-onset nephrotic syndrome. Examination by light microscopy, immunofluorescence, and electron microscopy (in one case) identified minimal change disease (MCD) in both cases. There was a potential causative drug (meloxicam) for the 73-year-old patient. Both patients were treated with prednisone and responded with complete remission. The patient with type 1 diabetes showed complete remission without relapse, and the patient with type 2 diabetes had two relapses; complete remission was sustained after associated treatment with cyclophosphamide and prednisone. Both patients had two years of follow-up evaluation after remission. We discuss the outcomes of both patients and emphasize the role of kidney biopsy in diabetic patients with an atypical proteinuric clinical course, because patients with MCD clearly respond to corticotherapy alone or in conjunction with other immunosuppressive agents.