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J Leibowitch

Publications and source records attributed to J Leibowitch.

7 recordsLinked to original sources
PubMed1979

[Description of an unusual enzymic activity cleaving the third component of complement].

A large enzymatic complex cleaving C3 (C3'ase) in the absence of magnesium (EDTA) has been partially characterized in two patients. On gel filtration EDTA-C3'ase was found in an 800 000 fraction containing antigenic C4, IgA and IgG in addition to alpha-2-macroglobulin and IgM normally present. EDTA-C3'ase was specifically neutralized by antibodies to IgG, IgA and C4. The characteristics of this unusual enzymatic complex are compatible with that of a C4b2a complex stabilized by its specific binding to an auto-antibody of the IgG and/or IgA class.

Chromatography, Gel↗
PubMed1979

Recurrence of dense deposits in transplanted kidneys: I. Sequential survey of the lesions.

Serial specimens from transplanted kidneys were obtained in 11 patients with dense deposit disease (DDD). The recurrence of DDD was obvious in 9 patients and appeared very early after grafting. Three different types of evolution of the lesions were observed. In 4 patients no modification of the lesions occurred with time, and in 2 of them the dense alteration alone persisted without any other glomerular changes. In 3 patients a progression of the lesions was observed, whereas a regression occurred in 1 other patient. From these observations the following sequence of the morphologic changes can be proposed: the dense alteration appears first and constitutes the specific marker of that disease; the C3 deposition in the kidney occurs later following the appearance of the dense lesion.

Basement Membrane↗
PubMed1979

Recurrence of dense deposits in transplanted kidney: II. Serum complement and nephritic factor profiles.

Dense deposit disease of the kidney is a rare form of chronic glomerulonephritis frequently associated with serum complement abnormalities (low C3 levels) and a circulating C3 convertase activator of the alternative pathway, the C3 nephritic factor (NF). Eleven patients with end-stage dense deposit disease underwent kidney transplantation. Of the 11, 7 had pretransplant low C3 and NF. In the posttransplant period, persisting low C3 levels were associated with persisting NF, although not quantitatively so. The original glomerular lesion recurred in the graft within 6 months in 9 of 11. Of these 9, 2 had no complement abnormalities either prior to or after transplantation. Pretransplant complement abnormalities were rapidly corrected in 4 of 7 patients whether or not recurrence of the original lesion occurred. Thus, serum complement profiles before and after transplantation are neither predictive nor indicative of recurrence.

Complement C3↗