The history of urinary microscopy to the end of the 19th century

In the 17th and 18th centuries, several authors performed urinary microscopy occasionally and were often unable to give their observations a practical diagnostic application. Such men included De Peiresc, Boerhaave, Ledermüller and Galeazzi. In the 1st half of the 19th century, however, urinary microscopy began to be used systematically. Rayer and Vigla identified for the first time elements other than crystals in urine and contributed to the methodology of handling samples for microscopy. Becquerel described dysmorphic erythrocytes, and Simon and Henle observed casts in urine and in histological preparations. In contrast, Bird mentioned casts only in passing, though he described many other elements and published the first complete book on urinary microscopy. The 2nd half of the 19th century was characterized by further advances, and in the book of Beale tubular cells were distinguished from other epithelial cells. Different types of casts were also linked with different renal diseases. By 1875 the classification of casts was complete. The work of the 19th century microscopists culminated in Rieder's book on clinical microscopy, which described each element of urinary sediment through 36 beautiful chromolithographic plates.

Late recurrence of systemic vasculitis after kidney transplantation involving the kidney allograft

A patient is described in whom a recurrence of vasculitis was observed in the kidney allograft six years after transplantation and one year after withdrawal of corticosteroid therapy. This case shows that systemic vasculitis may recur at any time after transplantation which implies a continuous and careful monitoring of these patients.

Acute tubular necrosis caused by gross hematuria in a patient with focal and segmental necrotizing glomerulonephritis

We describe a patient with gross hematuria, severe renal failure and symptoms suggestive of systemic vasculitis. Renal biopsy showed very focal and segmental necrotizing glomerulonephritis without crescents. A few C3 deposits were seen by immunofluorescence. The tubular lesions, on the contrary, were very severe, consisting of tubular cell necrosis and ruptured tubular basement membrane, associated with large numbers of intraluminal erythrocytes and erythrocytic casts. After gross hematuria had cleared, renal function slowly recovered. Because of biopsy findings and clinical course, acute renal failure in this patient was considered to be due to the tubular lesions caused by gross hematuria.

Utility of immunofluorescence of urine sediment for identifying patients with renal disease due to monoclonal gammopathies

Immunofluorescence (IF) of urine sediment with antisera to light-chain immunoglobulins (LC) was used for patients with renal disease due to various monoclonal gammopathies. Urinary casts and/or masses from 20 of 27 patients (74%) of this group stained predominantly for one or another of the two LC, but from none of the 25 controls, who all had renal diseases other than monoclonal gammopathies. In all but one patient with monoclonal gammopathy the more intensely staining LC in the urine sediment was the same as that found in the paraprotein. For 68.7% of patients, the prevailing LC in urinary casts was the same as that prevailing in the casts of the renal biopsies. The sensitivity of IF of urine sediment for identifying patients with plasma cell dyscrasias was 74%, the specificity 100%, and the accuracy 86.5%. The positive predictive value was 100% and the negative predictive value was 78%. Globally, urine sediment IF was more sensitive than serum or urine electrophoresis (74% v 63% and 66.6%), but less than serum or urine immunoelectrophoresis (74% v 85%). In light-chain deposition disease, a disorder in which there are often no definite symptoms, urine sediment IF was more sensitive than both traditional methods. We conclude that IF of urine sediment is a useful test to identify patients with renal disease associated with monoclonal gammopathies.

Comparison of immunofluorescent findings in kidney after snap-freezing and formalin fixation

Two types of tissue preparation for immunofluorescent staining were compared with sections of the same kidney. In one, formalin-fixed paraffin-embedded kidney sections were incubated with pronase (IF-PRON). The optimal pronase exposure for bright, specific IF and a mild background IF, suitable for the whole set of antisera was determined (pronase 0.75 g/l of Tris buffer for 60 min) and this was used for the subsequent steps of the study. Snap-frozen sections were also stained (IF-FROZ). Positive and negative cases, IF intensity, distribution and location in IgA nephropathy, membranous nephropathy, proliferative lupus nephritis were compared by the 2 methods. The main antigens for each disease were adequately revealed by IF-PRON, so that a correct diagnosis was possible in all cases. IF-PRON was also applied to sections before and after prolonged storage of blocks in the files, to see whether or not retrospective analysis is possible. Only minor differences were found between the 2 series of sections. Finally, the exposure of the sections to the continuous fluorescent light showed that IF fading was less in fixed sections. We conclude that IF-PRON is a reliable method for renal pathology with some advantages over the IF-FROZ.

Long-term outcome of Schönlein-Henoch nephritis in the adult

Sixteen adult patients with Schönlein-Henoch nephritis, selected by strict inclusion criteria, were studied retrospectively. At the time of discovery of the nephropathy, 11 patients had normal plasma creatinine and 5 other patients had renal insufficiency. All patients had renal biopsies, which were studied by both light and immunofluorescence microscopy. After a mean follow-up of 90.5 +/- 59.1 months (range 16-261), 3 patients were in chronic dialysis (18.7%), 8 other patients had renal function deterioration (50%), with creatinine clearance ranging from 31 to 60 ml/min. Four other patients had mild urinary abnormalities with normal plasma creatinine (25%) and only 1 patient was in complete clinical remission (6%). No clinical features at onset were predictive for the clinical outcome of the disease, while in the biopsies the percentage of crescents was higher in patients who developed renal insufficiency. High IgA serum levels were correlated (p = 0.0242) with a favorable course. It is concluded that Schönlein-Henoch nephritis of the adult carries a high long-term risk of renal dysfunction.