Are tissue samples from two different anatomical areas of the kidney necessary for adequate diagnosis?

BACKGROUND: An accurate histological diagnosis is of fundamental importance for the therapy and prognosis of many kidney diseases. However, it remains unclear whether a single biopsy is representative of changes in the whole kidney. METHODS: To compare the quantity and quality of renal biopsy material taken from two separate areas from one kidney, we prospectively biopsied the renal cortex at the central third and at one of the kidney poles of 103 consecutive 61 native and 42 transplanted kidneys. With two biopsy cores from each kidney we sampled 14.5 ± 8.5 glomeruli/procedure. RESULTS: The length of the biopsy core, the number of glomeruli/core and the markers of chronic renal damage (degree of interstitial fibrosis, proportion of global or segmental scared glomeruli) were not influenced by biopsy location (pole compared with central third locations). Moreover, there was no significant difference in the number of arteries in biopsies obtained from the two different biopsy areas. The percentage between renal cortex and medulla was not influenced by the biopsy area in all kidneys, but transplanted kidney biopsies contained more medulla than specimens from native kidneys. In patients with native kidneys and lower estimated creatinine clearances, there was a nonsignificant trend towards higher variations in the degree of interstitial fibrosis between the two cores, but a coincidence cannot be excluded. There was no significant difference in global sclerotic glomeruli in regard to the biopsy location. CONCLUSION: We conclude that a renal biopsy composed of two cores from different areas of the kidney provides enough material for histological diagnosis. However, despite the variety of different renal diseases, sampling errors are minimal and obtaining two biopsies from different areas of the kidney does not lead to clinically useful information which would alter the management of patients.

"Nearly a stairway to heaven"--severe dichromate intoxication in a young man.

A 22-year-old man presented with dichromate intoxication in a suicidal attempt. He exhibited signs of liver and renal toxicity and very high serum chromium levels. Since it has been reported in the literature that hemodialysis and hemoperfusion are not sufficient to remove chromium, we tried plasmapheresis considering the fact that chromium salts bind to protein. Five plasmapheresis treatment sessions significantly lowered his serum and urinary chromium concentrations. The patient survived without organ damage despite ingestion of a lethal dichromate dose and high serum chromium concentration. Thus, plasmapheresis should be considered as a potential therapeutic option to reduce chromium concentrations.

[Renal manifestations of light chain associated diseases - epidemiology and prognosis]. / Renale Manifestationen von Leichtkettenerkrankungen - Epidemiologie und Prognose.

BACKGROUND: An impaired renal function in light chain associated disorders may be caused by myeloma cast nephropathy (MCN) but also by AL-amyloidosis (AL-A) and monoclonal immundeposition disease (MIDD). PATIENTS AND METHODS: In a monocentric, retrospective analysis, patients suffering from multiple myeloma (MM) (n = 392) requiring medical therapy, AL-A (n = 53) or MIDD (n = 12) diagnosed between 1996 and 2008 were evaluated for renal insufficiency. The different patient cohorts were compared in terms of their clinical course and outcome. RESULTS: Renal insufficiency in MM-, AL-A- or MIDD-patients at the time of diagnosis was found in 45,5 % of the patients. MCN, AL-A and MIDD were found in 68, 25 and 6 %, respectively. Dialysis dependency was seen in 17 % of MCN, in 8 % of AL-A and in 50 % of MIDD patients. Signs of hypervolemia were the leading symptoms in MIDD/AL-A. The time between the occurence of first symptoms and diagnosis was as long as 52 weeks in patients with AL-A. Patients with renal involvement showed a reduced median survival of 17 compared with 77 months in patients with a normal renal function. Median survival was only 12 months in AL-A compared to 21 months in MCN. Stabilization of renal function after chemotherapy occurred only in MCN. Multivariate Cox regression analysis showed impaired renal function as independent risk factor (Hazard-Ratio 2,88 [2,06-4,0]. In terms of survival and kidney function, autologous stem cell transplantation (ASCT) was beneficial for patients with renal involvement. CONCLUSION: Renal insufficiency is an independent risk factor in MM, AL-A and MIDD. Specific therapy, especially ASCT may improve prognosis in patients with renal insufficiency and could stabilize renal function in MCN-patients.

[Rituximab as effective therapy in very severe thrombotic thrombocytopenic purpura (TTP)]. / Rituximab als effektive Therapie bei schwerster thrombotisch thrombozytopenischer Purpura (TTP).

HISTORY AND ADMISSION FINDINGS: A 26-year-old woman was admitted from another hospital because of an increased serum creatinine (170 micromol/l). She was found to have a thrombocytopenia (14Gpt/l, WHO grade IV) with anaemia and a raised lactate dehydrogenase (25.45 micromol/l). The patient was in a reduced general state when admitted to this hospital. Her mucosal membranes were pale and she had moderate scleral icterus. During the first few hours she became clearly less alert but without motor or sensory deficits. INVESTIGATIONS AND DIAGNOSIS: Laboratory tests showed an increased total bilirubin (73 micromol, decreased haptoglobin (< 0.08 g/l), free hemoglobin was raised (20.7 micromol/l) and the blood smear showed 5.5% fragmentocytes. Direct and indirect Coombs tests were negative. DIAGNOSIS, TREATMENT AND COURSE: Thrombotic thrombocytic purpura (TTP) was diagnosed. Daily plasmapheresis with fresh plasma replacement and administration of corticosteroids was initiated. ADAMTS13 activity (reported later) was < 2 % and antibodies against this protease were demonstrated. After initial improvement a motor and sensory aphasia occurred. Because of progressive thrombocytopenia, immunosuppression with a total of four doses of 375 mg/m(2)/bsa rituximab was undertaken (640 mg each), every seven days. Over the next two to three weeks the platelet count very slowly rose. The plasmapheresis was ended after a total of 65 sessions. Nine months after the last plasmapheresis the platelet count and renal functions were normal. CONCLUSION: Severe autoantibody TTP can be successfully treated by administering rituximanb, an anti-CD20 antibody, in addition to the standard treatment with plasmapheresis.