Clinical significance of plasma factor VIII levels in renal disease.

The plasma levels of factor VIII related antigen (FVIIIRA), factor VIII coagulant activity (FVIIIC) and the ratio between them were evaluated in 57 patients with kidney disease of diverse etiology, and with either normal (49) or impaired (8) renal function. Renal biopsy specimens were obtained from 47 patients with normal renal function. No correlation was observed between the increased plasma values of FVIIIRA and FVIIIC and renal function, histologic findings, and the pattern of deposition of immunoglobulin and complement. In contrast, plasma levels of both components of factor VIII were positively correlated with the magnitude of proteinuria. In the authors' opinion, the determination of factor VIII components is of no value in establishing the diagnosis and prognosis of patients with kidney disease. The finding on immunofluorescence of simultaneous deposition of factor VIII and C3 in the arteriolar walls might suggest incipient atherosclerotic damage. The FVIIIRA/FVIIIC ratio was increased in 87% of the patients and particularly in those with membrano-proliferative glomerulonephritis and chronic renal failure; however, the clinical relevance of this finding remains to be elucidated. The significant correlation between the two components suggests that in renal disease a simultaneous aggregation of the two proteins in factor VIII takes place.

Clinical significance of urinary fibrinogen degradation products in renal disease: study with two methods and correlation with histological findings of intraglomerular coagulation.

The investigation of fibrinogen degradation products (FDP) in urine has been suggested as a reliable method to detect the glomerular deposition of fibrin. Urinary FDP were investigated in 246 patients with renal disease by means of a latex test in 100 of them (positive in 54%); in the remaining 146 patients the Merskey method was used which gave positive results in 26% of them. A significant correlation between urinary protein excretion and FDP was only observed in those patients examined with the latex test. In patients investigated with the Merskey method, the simultaneous determination of serum FDP showed no correlation between FDP values in serum and urine. In those patients studied by means of renal biopsy, a poor correlation was observed between immunofluorescence and electron microscopic evidence of fibrin deposition and urinary FDP. In conclusion, isolated urinary FDP detection is not an index of pathologic coagulation in the glomeruli.

Light and electron microscopic findings in five cases of cryoglobulinemic glomerulonephritis.

Renal tissue from five patients with cryoglobulinemia was studied by light and electron microscopy and immunofluorescence. None of the histologic features observed at the light microscopic level seems to be specific for cryoglobulinemia. Electron microscopic investigations have shown very large electron dense deposits in almost every examined lobule in all cases. The deposits displayed two main patterns; a homogeneous texture in two cases and tubular or annular structures in three cases. The patients with typically structured deposits had IgG-IgM cryoglobulinemia (2 cases) or monoclonal IgM cryoglobulinemia (1 case). The presence of IgM in cryoglobulinemia may be the cause of the peculiar structure of the deposits.

125I-iothalamate and creatinine clearances in patients with chronic renal diseases.

In 196 adult patients with chronic renal disease or primary hypertension, the evaluation of glomerular filtration rate (GFR) by means of creatinine clearance, 'predicted' creatinine clearance and [125I]-iothalamate clearance was performed. Iothalamate clearance was evaluated after subcutaneous injection of the substance . In patients with normal or upper borderline plasma creatinine values, the iothalamate clearance ranged from 44 to 117 ml/min/1.73 m2 and the overestimation of GFR from creatinine clearance was negligible. In patients with mild or advanced renal failure, the overestimation of GFR from creatinine clearance increased up to 18 and 32%, respectively. The clinical usefulness of iothalamate clearance is evident especially in patients with mild renal failure, in whom an accurate evaluation of GFR is often important for a correct dietary and therapeutic approach.

Renal histologic and ultrastructural findings in psychogenic polydipsia and diabetes insipidus.

The renal biopsies of 15 patients affected by polydipsia syndromes were examined under light and electron microscopes. The authors contend that the observed renal lesions (dilatation of the glomerular loops, tubular hypertrophy and vacuolization, and basal membrane swelling) are the morphologic result of tubular hyperfunction in the service of ion reabsorption. This, in turn, is secondary to the increased GFR.