Biomedical subjects

J Forristal

Publications and source records attributed to J Forristal.

6 recordsLinked to original sources

PubMed1979

Idiopathic rapidly progressive glomerulonephritis with C3 nephritic factor and hypocomplementemia.

A 7-year-old boy with mild renal failure and signs and symptoms of acute poststreptococcal glomerulonephritis including severe hypocomplementemia had, by renal biopsy, numerous crescents but no deposits in the glomerular capillary loops. Instead, deposits identical in location and composition to those described for children with idiopathic rapidly progressive glomerulonephritis were present. The severe hypocomplementemia was found to be due to high levels of C3 nephritic factor; niether nephritic factor nor hypocomplementemia has been reported in rapidly progressive glomerulonephritis of the idiopathic type. Following prompt therapy with methylprednisolone intravenously, serologic abnormalities disappeared and renal function greatly improved, but a later biopsy showed 50% of the glomeruli obliterated by scarring. The case is of importance not only in indicating that severe hypocomplementemia does not rule out idiopathic rapidly progressive glomerulonephritis but also in adding to the list of diseases in which nephritic factor can be found.

Antigen-Antibody Complex↗

PubMed1979

Glomerular deposition of complement-control proteins in acute and chronic glomerulonephritis.

Acute poststreptococcal glomerulonephritis (AGN) differed from membranoproliferative glomerulonephritis (MPGN) and lupus nephritis (SLE) in that two of the proteins that control the C3b-dependent convertase, beta 1H and the C3bC4b-inactivator cofactor (C3bC4bICo), were frequently absent from the glomerular deposits. In addition, factor B was distributed with C3 in the capillary walls in hypocomplementemic AGN patients. From this, it can be assumed that C3bBb is in the deposits, uninhibited by control proteins as would be predicted for alternative pathway activation. Factor B could not be found in normocomplementemic AGN, was rarely present in MPGN, but was usually present in SLE, most often in the mesangium. In MPGN and SLE, the control proteins were nearly always present in the glomeruli in a distribution like that of C3; IN MPGN they were particularly abundant. Complement profiles indicated an occasional transient reduction in serum C4 level early in AGN. Thus, although there is occasional evidence of early classical activation in AGN, more characteristic is a long period of alternative activation. Serum levels of control proteins did not deviate greatly from normal except for reduced serum beta 1H levels in MPGN type I.

Biopsy, Needle↗

PubMed1979

Serum complement levels in infancy: age related changes.

Levels of eight complement components and two control proteins, were determined on cord serum from normal full term neonates and serum from healthy infants aged 1 and 6 months. For all proteins, the levels were below the adult normal at birth and rose toward the adult range by age 6 months. In a second group of 271 patients, ages 1-36 months, serum Clq and properdin levels were measured. For both proteins, the mean values in early infancy were more than two SD below the adult range and did not reach the adult range until 18-21 months of age. The Clq concentration was more variable than that for any other component studied. In infants from 11 months-3 yr of age, Clq levels correlated with serum IgG levels, but properdin levels did not.

Adult↗

PubMed1978

Remissions induced in hereditary angioneurotic edema with an attenuated androgen (danazol): correlation between concentrations of C1-inhibitor and the forth and second components of complement.

Serum concentrations of antigenic and functional C1-INH increased in patients in whom remissions from attacks of HANE were induced with danazol. The levels of C4 were directly related to serum concentrations of C1-INH antigens up to a concentration of about half the C1-INH found in normal plasma; at this point, the C4 concentrations were in the normal range and no longer correlated well with C1-INH concentration. Serum C2 levels correlated less well with C1-INH concentration. In normal serum there was a poor correlation between C1-INH, C4, and C2 levels, suggesting that C1-INH is normally present in excess of the amount needed for normal C4 levels. The increments in serum C1-INH were related to the dose of danazol.

Angioedema↗

PubMed1977

Alternative pathway of complement in sickle cell disease.

Thirty-one patients, 10 months to 20 years of age, were studied. A complement abnormality was not identified in sera from patients with sickle cell disease (SCD) by the methods employed in the present study. Concentrations of C3, factor B, total hemolytic activity (CH50), properdin, and C3b inactivator were similar in sera from patients and control subjects (Table 1 and Fig. 2). Although concentrations of C3b inactivator protein were below normal in a few patients, there was no evidence that these levels were low enough to alter the functions mediated by this protein. Initiation of the complement sequence via the alternative pathway by reaction with inulin was equal in patient and control sera when assessed by the activation of factor B, cleavage of C3 and the comsumption of hemolytic complement components (Table 1). Lysis of erythrocytes treated with reduced glutathione was similar in patient and control sera during alternative pathway activation (Fig. 3), indicating comparable formation of lytic complexes via this pathway. An abnormality of the alternative pathway was not detected when the serum from patients with sickle cell disease was reacted with inulin. Thus, this polysaccharide, although commonly empolyed to assess alternative pathway function, is not satisfactory for studying serum from these patients. In addition, activation of the alternative pathway by cobra venom factor was comparable with controls when assessed by the lysis of glutathione-treated erythrocytes.

Adolescent↗

PubMed1977

Correlations between serum factor B and C3b inactivator levels in normal subjects and in patients with infections, nephrosis and hypocomplementaemic glomerulonephritis.

In normal subjects, factor B and C3b inactivator (KAF) levels were linearly related (r = 0-71); factor B levels in subjects with low normal levels of KAF were significantly lower than in those with high normal levels of KAF. This relationship is postulated to be the result of modulation by the level of KAF of the availability of nascent, spontaneously formed, C3b, in turn responsible for a constant low-grade activation of the C3b feedback which determines in part the level of factor B. The correlation did not obtain in patients with infections; levels of KAF and, to a greater extent, factor B were elevated. In patients with glomerulonephritis and hypocomplementaemic because of in vivo classical pathway activation, KAF and factor B levels were also poorly correlated, presumably because many factors were influencing the levels of these proteins transcending the modulating effect of the concentration of KAF. On the other hand, in patients with nephrosis and with MPGN Type II, KAF and factor B levels were low but were directly correlated. In nephrosis the correlation may be the combined result of an equal rate of catabolism of these proteins and of modulation of factor B levels by the level of KAF as in normal subjects. In MPGN Type II, the correlation may reflect the fact, noted in in vitro studies, that with alternative pathway activation, the level of KAF influences the extent of factor B and C3 conversion to a greater extent than when complement is activated by the classical pathway.

Analysis of Variance↗