Shinya Inai

Reaction Mechanisms of β1H Globulin

The reaction mechanisms of β 1H were studied. The generation of alternative pathway C3 and C5 convertases on the cell surface as well as in the fluid phase was inhibited by

Inherited Deficiencies of the Late-Acting Complement Components Other than C9 Found among Healthy Blood Donors

Among sera from 145,640 healthy blood donors in Osaka, 16 were found to have abnormalities in late-acting complement components other than C9. It was found that of these 16 sera, 2 were deficient in C5, 4 in C6, 6 in C7 and 4 in C8 alpha-gamma-subunit. The incidence of deficiency of each component among the Osaka blood donors was calculated as follows: C5 deficiency, 0.0014%; C6 deficiency, 0.0027%; C7 deficiency, 0.0041%; C8 alpha-gamma-subunit deficiency, 0.0027%. We confirmed that 13 donors were healthy and 12 had no past history related to a complement component deficiency. From these results, not only C9 deficiency but also deficiencies of the other late-acting complement components were found among the healthy blood donors, but no early-acting component deficiencies were noted.

Complement fixing abilities of IgA myeloma protiens and their fragments: The activation of complement through the classical pathway

Abstract Complement fixing abilities of IgA and its fragments chemically aggregated were tested. Both IgA1 and IgA2 myeloma proteins fixed considerable amount of human complement. IgA2 fixed complement more efficiently than IgA1 did. Fc and F(ab′) 2 of IgA1 were more active than undigestived IgA1, and their activities were comparable to that of Fc of IgG, whereas the activity of F(ab′) 2 of IgA2 was weak. Complement component profiles of human serum treated either IgA or its fragments revealed that the classical pathway of the complement system was activated.

A new method for the preparation of EAC14 cell with human or guinea-pig serum

Abstract By reacting EA with serum in the presence of triethylenetetramine-N,N,N′,N″,N‴,N‴-hexa-acetic acid (TTHA), active and stable cellular intermediate of immune hemolysis, EAC14, was successfully prepared. This method does not require isolated components of complement and is applicable to prepare EAC14hu.

Paroxysmal nocturnal haemoglobinuria with coexisting deficiency of the ninth component of complement: lack of massive haemolytic attack

A 47‐year‐old woman with paroxysmal nocturnal haemoglobinuria (PNH) was found to have an inherited deficiency in the ninth complement component (C9). In complement‐sensitivity lysis tests, 80% of her erythrocytes were markedly complement‐sensitive (PNH‐III). Laser cytofluorimetry with a monoclonal antibody against decay‐accelerating factor (DAF) revealed that 95% of her erythrocytes were DAF‐negative. Surprisingly, she has suffered only mild haemolysis and has never experienced massive spontaneous haemolysis. Gross haemoglobinuria and jaundice occurred only after receiving postoperative transfusions of whole blood. In her serum, C9 was not detectable either by immunological or by functional assays. Both the Ham test and the sugar water test using normal human serum or plasma yielded marked haemolysis of the patients erythrocytes. When the patients serum or plasma was used, only a trace of lysis was detected. Addition of purified human C9 to her plasma fully restored haemolysis. These observations indicated that C9 may play a critical role in haemolytic attacks in patients with PNH and that characteristic haemolysis in PNH may be tempered by coexisting C9 deficiency.

Inactivator of the First Component of Human Complement (CĪINA)

Acidic mucopolysaccharides enhanced CĪINA activity against CĪs. The presence of heparin in the reaction mixture of CĪINA and CĪs markedly enhanced the inactivation of CĪs by potentiating CĪINA activit

Activation of the human complement cascade by bacterial cell walls, peptidoglycans, water-soluble peptidoglycan components, and synthetic muramylpeptides--studies on active components and structural requirements.

Cell walls isolated from 29 strains of 24 gram‐positive bacterial species, whose peptidoglycans belong to the group A type of Schleifer and Kandlers classification, with one exception (Arthrobacter sp.), were shown to activate the complement cascade in pooled fresh human serum mainly through the alternative pathway and partly through the classical one. The complement‐activating effect of cell walls (5 species) possessing group B type peptidoglycan, except those of Corynebacterium insidiosum, was weaker than that of the walls with group A type peptidoglycan. Preparations of peptidoglycan isolated from cell walls of Staphylococcus aureus, Streptococcus pyogenes, and Lactobacillus plantarum also activated the alternative pathway of the complement cascade, but less effectively than the respective parent cell walls. A water‐soluble “polymer” of peptidoglycan subunits (SEPS), which was prepared from Staphylococcus epidermidis peptidoglycans by treatment with a cross‐bridge degrading endopeptidase, retained most of the complement‐activating ability of the parent cell walls. A peptidoglycan “monomer,” SEPS‐M, which was obtained by hydrolysis of the glycan chain of SEPS with endo‐N‐acetylmuramidase to disaccharide units did not activate complement. In conformity with this finding, neither synthetic N‐acetylmuramyl‐l‐alanyl‐d‐isoglutamine (MDP) nor MDP‐l‐Lys‐d‐Ala activated the complement cascade. Among several lipophilic derivatives of MDP, 6‐O‐(3‐hydroxy‐3‐docosylhexacosanoyl)‐MDP‐l‐Lys‐d‐Ala (BH48‐MDP‐l‐Lys‐d‐Ala) and 6‐O‐(2‐tetradecylhexadecanoyl)‐MDP (B30‐MDP) were shown to activate complement through the alternative as well as the classical pathway and exclusively through the classical pathway, respectively. The finding that a d‐isoasparagine analog of B30‐MDP caused the same effect as the parent molecule strongly suggests that the activation of complement by B30‐MDP is different from that caused by cell wall peptidoglycans and a water‐soluble “polymer” of peptidoglycan subunits.

The activation mechanism of the alternative pathway of the human complement system by the immune precipitate formed with F(ab′)2 of rabbit IgG antibody: The generation of C3- and C5-cleaving enzymes of the immune precipitate

Abstract Immune precipitate (F), formed between egg albumin and the F(ab′)2 fragment of rabbit anti-egg albumin, activated the alternative pathway of the complement system in human serum. On incubation with serum, F combined with several factors in serum (X) to form a complex, FX, which was capable on inactivating purified C3 and C5. FX having maximal activity was obtained by incubation of F with serum for 10–20 min (Tmax). Tmax depended on the amount of F added to serum and a increased amound of F shortened the Tmax/ When FX was incubated at 37°C, its activities decayed as a first order reaction and were completely lost in 120 min. FX regenerated from decayed FX (FXd) by the addition of both B and D . FX also lost activity by treatment with anti-B or anti-C3. These findings indicated that F(ab′)2 activated the alternative pathway of the complement system in human serum by the formation of the properdin system enzymes on F.

High-incidence of C9 deficiency throughout Japan: there are no significant differences in incidence among eight areas of Japan.

From 92,686 sera sent from hospitals throughout Japan to the Special Reference Laboratories for CH50 assay, we were able to classify 80 patients as C9-deficient using a sensitive screening test, as well as hemolytic and immunochemical C9 assays. The incidence of C9 deficiency was determined to be 0.086%, and there were no distinct differences among the eight areas of Japan tested. Serum CH50 levels of these C9-deficient patients varied widely (9.4-63.8 U/ml), and exhibited a higher value (average: 34.1 U/ml) than that of healthy C9-deficient individuals, probably due to elevated C3, C4, and C5 levels. These patients suffered from a variety of autoimmune, renal, and infectious diseases, which, however, are thought to be only incidentally associated with C9 deficiency.

Studies of four Japanese families with hereditary angioneurotic edema: Simultaneous activation of plasma protease systems and exogenous triggering stimuli

SummaryForty-five relatives of 4 families with hereditary angioneurotic edema (HANE) were studied. Twenty-five, including 11 asymptomatic kindreds with the disposition, showed typical changes in complement system compatible with HANE. Follow-up study of HANE patients showed that, even in remission period, complement, coagulation and fibrinolytic systems can be activated. During edema attacks, moderate haemoconcentration and neutrophilia were encountered and kallikrein-kinin system was found to be also activated. Replacement therapy with C