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PubMed1983

[Complement components, whole complement activity, and circulating immune complexes in neoplastic diseases].

Serum levels of complement components(cc), whole complement activity (CH 50), and circulating immune complexes (IC) were measured in 41 patients with neoplastic diseases. The level of cc was higher than in healthy controls; the levels of C1q, C1INA, C4, C3c, C3ACT, C5, and C9 were statistically higher. In patients with lung cancer, the levels of cc were correlated with the clinical stage as well as the performance status. Both the IC serum level and the incidence of high serum IC levels in lung cancer were higher in stage III and IV than in stage I and II. Serum CH 50 was higher than in healthy controls, but not correlated with the clinical stage.

Aged↗
PubMed1983

Heparin-stimulated modification of C1-inhibitor by subcomponent C1s of human complement.

C1-inhibitor and C1s form a very stable complex which migrates with an apparent molecular mass of 180 kDa in dodecyl sulfate gel electrophoresis. A small fraction of the inhibitor (100 kDa) was found to be converted to a large (95 kDa) and a small (2 to 5 kDa) fragment during this reaction. It is concluded that C1-inhibitor is modified by C1s in a similar way as are the related plasma inhibitors alpha 1-proteinase inhibitor, antithrombin III and antiplasmin by their specific proteinases. The fraction of modified C1-inhibitor increased when heparin was present during complex formation. This reaction was complete after 15 s and is comparable with the fast heparin induced formation of modified antithrombin III. Treatment with hydroxylamine led to a complete dissociation of the inhibitor-enzyme complex by dodecyl sulfate. The large inhibitor fragment (and not unmodified inhibitor as reported by other authors) was released.

Complement Activating Enzymes↗
PubMed1983

C1 inactivator-C1s complexes in inflammatory joint disease.

A newly developed enzyme linked immunosorbent assay for the quantitation of C1 inhibitor (C1In)-C1s complexes was used to study activation of the classical pathway of complement in inflammatory joint diseases. Synovial fluid (SF) specimens were obtained from patients with rheumatoid arthritis (RA), other arthritides and non-inflammatory joint effusions. Paired serum (S) samples were obtained in 17 cases. Immune complexes (IC) were measured by the staphylococcal binding assay. C1In-C1s were higher in RA SF samples than in paired RAS samples (P less than 0.01). IC were higher in RA SF than non-RA SF. There was a significant inverse correlation between SF C1In-C1s complexes and SF total haemolytic complement. For all SF samples there was a correlation between IC and C1In-C1s complexes, but for RA SF alone there was no significant correlation between these parameters. There was no correlation between titre of rheumatoid factor and C1In-C1s complexes. These results demonstrate that activation of the classical pathway of complement is the hallmark of rheumatoid synovitis, yet also suggest functional heterogeneity of both circulating and intra-articular IC.

Antigen-Antibody Complex↗
PubMed1983

Preliminary observations on danazol therapy of systemic lupus erythematosus: effects on DNA antibodies, thrombocytopenia and complement.

Seven patients with systemic lupus erythematosus (SLE) were treated with Danazol in a controlled study. Phenomena observed in some patients treated with Danazol were: 1) decrease in immunoglobulins and antibodies to native DNA; 2) increases in serum complement and platelets; and 3) clinical improvement. Ineffective drug trials were associated with increasing disease activity. Drug side effects were minimal. It appears that the drug may have an ameliorative effect on mildly active SLE patients and sometimes a marked effect on thrombocytopenia. Further evaluation of Danazol appears to be warranted for these types of patients but not for treatment of acute or severe forms of the disease.

Adult↗
PubMed1983

[New preparation method of C1 esterase for the dosage of its plasma inhibitor].

A purification method for C1 esterase is described. The final product significantly improved the sensitivity and the specificity of the enzymatic measurement of its plasma inhibitor C1-INH or alpha 2-neuraminoglycoprotein (alpha 2-NGP) by esterolysis of a synthetic substrate N-acetyl-L-tyrosine ethyl ester (ALTEe). A comparative study was done between the chromatographed C1 esterase and the native serum euglobulins: qualitative and quantitative determination of the serum contaminants, enzymatic activity measurement of C1-INH in normal subjects and in patients suffering from hereditary angioneurotic oedema (OANH) as well as in therapeutical C1-inhibitor concentrates.

Angioedema↗
PubMed1983

[Immune complex and complement levels in spontaneous abortions and normal pregnancy].

We gave attention to the following as specific immunological tolerance factors in pregnancy: a) the serum levels of circulated immune complex (IC), b) serum complement levels (C1q, C3, C4, C1-Inhibitor). The results were as follows: In spontaneous abortions measured by C1q binding test (Zubler et al.) IC levels did not differ significantly from those in normal pregnancies in the first trimester, but in both cases, IC levels were slightly higher than the levels in nonpregnant women. C1q and C1-Inhibitor levels in normal pregnancies were significantly lower than in nonpregnant women, and both levels in spontaneous abortions were significantly higher than in normal pregnancies. In cases of artificial and spontaneous abortions, increased IC levels were rapidly lowered to the normal range within 7 days after treatment and lowered C1q and C1-Inhibitor levels also returned to the normal range within 7 days. But these trends were more remarkable in artificial abortions. However, C3 and C4 levels did not change after treatment in either case. A negative correlation between complement levels (C1q, C3, C4) and IC levels in the third trimester was demonstrated in our study.

Abortion, Spontaneous↗
PubMed1983

[Hereditary angioedema. A hereditary disorder in the synthesis of the complement system].

Hereditary angioedema is characterized by recurrent attacks of painless, non itching edema of the face and limbs and sometimes by abdominal symptoms. It is due to a deficiency of functional inhibitor of the first component of complement (C1 Inh). We present a case where a normal antigenic level of C1 Inh was found but no functional activity was present (B variant). A short review is given of the pathogenesis, heredity, diagnosis and treatment of the disease.

Adult↗
PubMed1983

Acquired C1-esterase inhibitor deficiency and recurrent herpes infection in a patient with chronic lymphocytic leukemia.

Profound hypocomplementemia was observed in a patient with chronic lymphocytic leukemia. On the basis of the results of complement measurements performed in nine serum samples taken in a period of 6 mo it was demonstrated that the patient had an acquired form of C1-esterase inhibitor deficiency: marked reduction of CH50, C1, C4, and C1-esterase inhibitor levels with normal alternative pathway, C3, and factor B activities were found. The patient had no typical attacks of angioneurotic edema; however, angioedema-like facial swelling was observed on several occasions in connection with recurrent severe herpes simplex eruptions. The possible association of the marked and long-lasting hypocomplementemia with the clinical course of the herpes infection is discussed.

Angioedema↗
PubMed1982

The inhibition by lysine of the activation of the first component of complement, C1.

Lysine prevented the activation of Cl at low ionic strength or by heat aggregated IgG (aggIgG) measured by the hydrolysis of acetyl tyrosine ethyl ester (ATEe) by Cls. When serum was mixed with aggIgG, complement was activated and consumed. If lysine was present in the serum containing aggIgG, the activation of complement, thus its consumption, was inhibited in a dose-response manner. Cl haemolysis assay which measures the Cl activity to interact with EA (erythrocytes bound with antibody) was used to study the effects of lysine. The results indicate that 50% of Cl haemolysis was inhibited at 3 mM of lysine. Crossed immunoelectrophoresis indicates that Cl in the serum was activated by aggIgG, but Cls thus formed seemed to be soon complexed with Cl inactivator. The presence of lysine prevented the conversion of Cls to Cls completely. It might be possible that lysine binds with the binding sites on Clq, thus preventing the interaction of Clq and C gamma 2.

Complement Activation↗
PubMed1983

C1- inactivator: its efficiency as a regulator of classical complement pathway activation by soluble IgG aggregates.

The role of C1- inactivator (C1(-)-In) during activation of the classical complement pathway by soluble immune complexes was studied using purified human complement components C1, C4 and C1(-)-In, and stabilized soluble aggregates of normal human IgG as a model for soluble immune complexes. The C4-consuming ability that could be generated by incubation of precursor C1 with IgG aggregates was abolished completely by the presence of a large excess of C1(-)-In during the C1 activation step. Kinetic studies confirmed that this inhibition was due to a second-order reaction between C1- and C1(-)-In resulting in the irreversible inactivation of C1-. When aggregates of various sizes were enabled to induce C4 conversion in mixtures of C1, C4 and a variable concentration of C1(-)-In, the presence of C1(-)-In had two effects. Firstly, the efficiency of the aggregates in causing C4 consumption was reduced remarkably. At a C1(-)-In:C1 ratio of 8, which can be found in normal human serum, approximately eight to ten times as many aggregates were required for a given level of C4 consumption as when no C1(-)-In was present. Secondly, C1(-)-In diminished the maximum C4 consumption that could be achieved, especially with smaller aggregates. Thus, a complete or partial C1(-)-In deficiency probably facilitates complement activation by soluble immune complexes in two ways: it may enhance the efficiency of classical pathway activation by all C1-activating complexes, and it may enable small complexes, which normally cannot overcome the C1(-)-In barrier, to activate the classical pathway to the C4 level.

Antigen-Antibody Complex↗