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K Neelakantappa

Publications and source records attributed to K Neelakantappa.

7 recordsLinked to original sources
PubMed1993

Ranitidine-associated interstitial nephritis and Fanconi syndrome.

Ranitidine is an H2 blocking agent widely used in the treatment of peptic ulcer disease. Although acute interstitial nephritis has been described in association with a related drug, cimetidine, this complication secondary to ranitidine has been reported only once before. We describe a patient who presented with acute renal failure and features of Fanconi syndrome in association with the use of ranitidine. Renal biopsy showed acute interstitial nephritis. The patient had renal tubular acidosis with alkaline urine, aminoaciduria, renal glycosuria, uricosuria, and phosphaturia. There was a marked disparity between the degree of elevation of urea nitrogen and creatinine concentrations in the serum that was attributable to diminished urea generation, since simultaneous measurement of inulin, creatinine, and urea clearances showed that they were comparably reduced. Urinary nitrogen loss in the form of aminoaciduria contributed significantly to decreased urea generation. Both acute renal failure and Fanconi syndrome resolved after treatment with prednisone.

Adult↗
PubMed1990

Microvascular disease and the progression of IgA nephropathy.

In order to examine the role of microvascular disease in the evolution of IgA nephropathy (IgAN), the interrelationships among vascular sclerosis, glomerular sclerosis, age, and hypertension were determined by morphometric analysis of renal biopsies in 71 patients with IgAN; 63 age- and sex-matched individuals with minimal change nephrotic syndrome (MCNS) served as normal controls. The following parameters in glomeruli and in vessels with an outer diameter of 60 microns or less were analyzed by multiple regression analysis: (1) percentage of glomeruli with segmental and/or global sclerosis; (2) percentage of vessel area in renal cortical tissue measured by the point-counting method; (3) index of hyaline change estimated as the percentage of the number of arteries showing hyaline change; (4) index of vessel wall thickness determined by the ratio of mural thickness to outer diameter of arteries; (5) number of vascular cross sections counted per 6.25 microns2. The results of the multiple regression analysis demonstrate that glomerular and vascular sclerosis are interrelated and that hypertension and vessel area are almost equally important as predictors of glomerular sclerosis. Vessel area proved to be an early marker of vasculopathy, as its values in IgAN, even in the absence of hypertension and/or glomerular sclerosis, exceeded those in age- and sex-matched controls (with MCNS). These data, obtained by the use of quantitative methods, establish a role for vessel disease and hypertension in the progression of IgAN.

Adult↗
PubMed1988

Prognostic pathologic markers in IgA nephropathy.

Previous studies have shown that the overall severity of the histologic grade and the extent of glomerular sclerosis are important pathologic markers of prognosis in IgA nephropathy. A previous analysis of the clinical and pathologic parameters in 74 patients at New York University Medical Center revealed that the renal survival (serum creatinine concentration of 2 mg/dL or less) was 100% in patients with mild proteinuria, 87% in those with moderate proteninuria, and 69% in those with heavy proteinuria. The incidence of segmental and global proliferation, glomerular sclerosis, tubulointerstitial damage, and vessel sclerosis increased with levels of proteinuria (P less than 0.01 to 0.05). A comparison of the morphologic parameters in 30 patients with similar initial serum creatinine concentrations (less than or equal to 2 mg/dL) but different outcomes demonstrates a greater incidence and severity of pathologic features, especially glomerular sclerosis in the "nonsurvival" than "survival" groups. Vessel sclerosis as quantitatively measured by a "point-count" technique correlates with the extent of glomerular sclerosis (r = 0.5192; P less than 0.001), suggesting a causal relationship or common basis.

Glomerulonephritis, IGA↗
PubMed1988

Proteinuria in IgA nephropathy.

Clinicopathological data in 74 patients with IgA nephropathy were analyzed with special attention to level of proteinuria and its prognostic significance in this disease. Excretion rates exceeding 3 g per day (heavy), in the range of 1 to 2.9 g (moderate) and under 1 g per day (mild) each occurred in approximately equal proportions of patients. One-sixth of those with more than 1 g developed end-stage renal failure, while serum creatinine never exceeded 2 mg/dl in any with mild proteinuria. "Renal survival" (serum creatinine of 2 mg/dl or less) at five years after presentation was 100% in patients with persistently mild proteinuria, 87% in those whose protein excretion reached the moderate range, and 69% when heavy or nephrotic range proteinuria developed. Of significance, only rarely did mild proteinuria at presentation increase to higher levels. A correlation existed between level of protein excretion and severity of mesangial, segmental or global proliferation, glomerulosclerosis, podocyte effacement, interstitial infiltration, tubular atrophy and vascular sclerosis, even in patients with unimpaired renal function. Moderate or heavy proteinuria typically preceded the onset of hypertension and occurred prior to the development of renal insufficiency. Our results underscore magnitude of proteinuria as an early marker of glomerular damage in the prognosis of IgA nephropathy.

Adult↗