Pattern of C3, iC3b, and C3d in patients hospitalized for acute asthma.

Twenty-three patients hospitalized for acute asthma were studied for a peripheral blood complement profile consisting of C3, C4, C3d, iC3b, C4d, and Bb concentrations. Compared with normals (n = 22) and patients (n = 10) with acute bacterial infections (ABI), asthmatic patients had significantly higher serum C3 concentrations (P less than .001). Plasma C3d levels and iC3b in asthmatic patients were both comparable to those observed in normal controls, whereas patients with ABI had significantly higher iC3b levels than both other groups. The ratio of iC3b to C3 concentrations were similar in asthmatic patients and controls, and iC3b levels were correlated with total serum C3 levels in asthmatic patients (r = .55, p less than .001) as well as in normal (r = .69, p less than .001). Both of these groups had significantly lower iC3b to C3 ratios compared with the ABI group (P less than .0001). Also observed in asthmatic patients were a significant correlation between serum C4 and C3 levels (r = .83, P less than .001) and a lower mean ratio of plasma C4d to C4 compared with normals (P less than .005). This profile of complement alterations is distinct from that observed in acute bacterial infection. These changes in asthmatic patients may relate to an acute phase reaction phenomenon affecting complement and/or complement regulatory proteins.

Diminished IgG, but not complement C3 or C4 or factor B, precedes nosocomial bacterial sepsis in very low birth weight neonates.

The significance of low serum IgG and complement proteins in very low birth weight (VLBW; less than 1500 g) neonates is not known. Therefore serum IgG, C3, C4 and Factor B were quantitated weekly by rate nephelometry in 15 VLBW neonates who developed proven nosocomial bacterial or candidal sepsis (Group A) and 27 VLBW neonates who did not develop sepsis (Group B). In the first week of life the serum IgG of neonates in Group A was 295 +/- 33 mg/dl (mean +/- SEM) and in Group B it was 440 +/- 21 mg/dl (P less than 0.01). In the second week, the IgG of Group A was 270 +/- 32 mg/dl and that of Group B was 473 +/- 38 mg/dl (P less than 0.01). If the IgG was less than 350 mg/dl in the first week or less than 230 mg/dl in the second week, the relative risk of acquiring sepsis was greater than or equal to 5 (95% confidence interval in the first week, 1.7 to 11.2). The serum IgG was measured before the onset of sepsis in 14 of the 15 neonates in Group A. In the week before sepsis the IgG of the 14 neonates was less than 440 mg/dl (range, 45 to 433 mg/dl) in all cases, was below the mean IgG of Group B in 12 of 14 cases (P = 0.006 vs. Group B) and was greater than 2 SD below the mean IgG of Group B in 4 of 14 cases (P = 0.0003 vs. Group B).(ABSTRACT TRUNCATED AT 250 WORDS)

Serum levels of ceruloplasmin, properdin factor B and copper in lymphoma patients.

The serum levels of Ceruloplasmin (CER), Properdin Factor B (PFB) and Copper (CU) were evaluated in a series of 40 patients with Hodgkin's Disease and 46 patients with non-Hodgkin's lymphoma. Concentrations of CER and PFB were determined by rate nephelometry and CU concentrations by the bathocuproine colorimetric method. The results obtained demonstrated that CER, together with the well documented CU, can be used for monitoring Hodgkin's Disease.

Properdin factor B allotypes in diabetic Nigerians. A preliminary report on chromosome 6 markers.

Properdin factor B(Bf) allotypes were determined in patients with insulin dependent (type 1) diabetes mellitus (n = 15); in patients with non-insulin dependent diabetes mellitus n = 15); and in healthy Nigerians (n = 252) from various tribal groups. In all three groups only commonly reported Bf allotypes namely BfF, F1, S and S1 were observed. More important, BfF1 allele was significantly increased in patients with insulin dependent (type 1) diabetes mellitus (expected 1/15, observed 5/15), X2 = P less than 0.005). It is suggested that this allele is probably the same as that reported in caucasoids and is part of a supratype or ancestral haplotype defined by HLA-B18, C4A3, C4A3, BQo, BfF1, DR3 marking type 1 (insulin dependent) diabetes mellitus.

C9 and factor B as acute phase proteins and their diagnostic and prognostic value in disease.

Some components of complement, such as C3, C9 and factor B, behave as acute phase reactants and their serum levels increase significantly in the course of inflammation. The diagnostic and prognostic significance of estimating the serum levels of C9 and factor B was evaluated in patients with Behçet's syndrome, recurrent oral ulceration and Crohn's disease, and the results were compared with those of measuring other acute phase reactants, such as C-reactive protein or alpha 1-antitrypsin. Longitudinal studies in these patients show a clear correlation between clinical indexes of the disease and levels of C9 and factor B. These findings, and experimental studies in monkeys, suggest that inflammation variously affects the synthesis of the acute phase reactants and that they play different roles as mediators of cellular damage.

C3 nephritic factor in a patient with recurrent Neisseria meningitidis infections.

A 15-year-old female experienced two systemic infections with N.meningitidis (group C and B) within a two months period. Classical as well as alternative pathway CH50 determinations on the patients serum showed no lysis. All individual complement factor concentrations, except for C3, were found to be within the reference area. Crossed immunoelectrophoretic analysis of C3 revealed no demonstrable native C3. The patient had normal levels of C3c and a markedly elevated C3d concentration. Serum from the patient was found to convert all native C3 in normal sera within 10 minutes at 37 degrees C. The active converting principle, present in the IgG fraction activated C3 in C4-depleted serum, and had a dose dependent stabilizing effect on the EA-C3bBb complex. The isolated factor showing the characteristics of C3 nephritic factor (C3 NeF), was unchanged in the patients serum over a ten months observation period. Circulating immune complexes (IC) could not be demonstrated by a C1q-dependent assay but the patients capacity to solubilize preformed IC in vitro was virtually abolished. The patient had no signs of renal disease or lipodystrophy.

Properdin factor b-polymorphism in the population of Hessen, Germany.

The polymorphism of properdin factor B (Bf, C3 proactivator) in a population sample from Hessen, Germany has been investigated by agarose gel electrophoresis and immunofixation. In 522 unrelated individuals seven different phenotypes were observed and the following allele frequencies calculated: BfS = 0.7998, BfF = 0.1772, BfS0.7 = 0.0163 and BfF1 = 0.0077. Investigations of 100 families with 198 children and 30 mother-child combinations support the assumed autosomal codominant way of inheritance.