Unmasking of acquired autoimmune C1-inhibitor deficiency by an angiotensin-converting enzyme inhibitor.

BACKGROUND: A majority of angioedema arise from unknown etiologies. Angioedema may also arise from medications or deficiency of C1-esterase inhibitor (C1-INH); either of these may lead to recurrent, sometimes life-threatening attacks of subcutaneous or submucosal edema if the angioedema involves the tongue, throat, or larynx. We describe a patient with unknown acquired C1-INH deficiency, who experienced only mild attacks of angioedema before treatment with an angiotensin-converting enzyme (ACE) inhibitor. This therapy led to life-threatening respiratory distress. OBJECTIVE: To investigate this patient's life-threatening angioedema. METHODS: Serum protein electrophoresis and immunofixation were performed. The titer of anti-C1-inhibitor autoantibody was determined by ELISA, and the specificity of the autoantibody demonstrated by using purified C1-INH to block binding in the ELISA. Finally, fractions from the immunoelectrophoresis gel were tested for C1-INH autoantibody by ELISA. RESULTS: Complement activation was documented by reduced C1-INH, C1q, and C4, and the patient was found to have an autoantibody of IgG2 isotype specific for C1-INH. After discontinuation of the ACE inhibitor, he continued to have decreased C1-INH and positive C1-INH autoantibodies. CONCLUSIONS: This case describes a patient who had a history of mild facial and extremity swelling with abdominal symptoms before ACE inhibitor treatment; this medication resulted in life-threatening respiratory distress. The use of the ACE inhibitor may have unmasked this patient's acquired autoimmune C1-INH deficiency.

A murine model of IgE-mediated cow's milk hypersensitivity.

BACKGROUND: Cow's milk allergy (CMA) is one of the leading causes of food allergy in children. Understanding the mechanisms involved in the development of CMA has been hampered by the lack of suitable animal models. OBJECTIVE: We sought to develop a mouse model of IgE-mediated cow's milk hypersensitivity (CMH) that mimics the clinical features of immediate CMA in humans. METHODS: Three-week-old C3H/HeJ mice were sensitized by intragastric administration of cow's milk (CM) plus cholera toxin and boosted 5 times at weekly intervals. RESULTS: CM-specific IgE antibody levels were significantly increased at 3 weeks and peaked at 6 weeks after the initial feeding. Intragastric challenge with CM at week 6 elicited systemic anaphylaxis accompanied by vascular leakage, significantly increased plasma histamine, and increased intestinal permeability to casein. Histologic examination of intestinal tissue revealed marked vascular congestion, edema, and sloughing of enterocytes. The role of IgE in mediating CMH was confirmed by abrogation of passive cutaneous anaphylaxis reactions by heat inactivation of immune sera. Development of IgE-mediated CMH in this model is likely to be TH2 cell mediated because in vitro stimulation of spleen cells from mice allergic to CM induced significant increases in the levels of IL-4 and IL-5, but not IFN-gamma. CONCLUSION: This model should provide a useful tool for evaluating the immunopathogenic mechanisms involved in CMA and for exploring new therapeutic approaches.

Esophageal obstruction after incomplete removal of a percutaneous endoscopic gastrostomy tube.

This two-year-old boy presented with a two-day history of vomiting and fever. He was diagnosed with acute otitis media four days before this incident. Repeated questioning revealed removal of a percutaneous enterostomy tube two weeks earlier with failure to pass the internal bumper in his stool. The child was in no distress, except for repeated emesis and drooling. A chest x-ray revealed a foreign body in the esophagus, and the patient underwent removal of the percutaneous endoscopic gastrostomy plastic bumper by endoscopy without incident.

Control of IgE responses. V. Oral administration of a synthetic derivative of the inner bacterial cell wall (SDZ 280.636) to sensitized mice induces isotype specific suppression of peak hapten specific IgE antibody forming cell responses, serum IgE levels and immediate hypersensitivity responses.

SDZ 280.636, a nontoxic diacyl glycerol derivative of muramyl dipeptide (MDP), a component of the inner bacterial cell wall, which is suitable for use in man, suppressed hapten specific IgE antibody forming cell (AFC) responses in spleen, serum levels of hapten specific IgE and hapten specific immediate hypersensitivity (i.h.) responses in skin, when fed to mice at the peak of a hapten specific IgE AFC response. In addition, serum levels of IL-6 appeared increased while IFN gamma was decreased. To induce these IgE responses, BALB/c mice were injected i.p. with BPO-KLH (benzylpenicilloyl-keyhole limpet hemocyanin) (10 micrograms) in aluminum hydroxide gel (alum) on days 0, 21 and 42. Mice were fed (gavage) with either MDP or SDZ 280.636 (1.0 or 10 mg/kg) on day 44, or on days 44, 46 and 48, and killed on days 46 or 50. Numbers of BPO specific AFC in spleen, and serum levels of BPO specific immunoglobulins (IgG1, IgE and IgA) were determined (ELISPOT assay, ELISA). In addition, BPO specific IH responses were measured in these animals. Mice were injected in the right pinna with BPO-BSA (0.1 microgram) and in the left pinna with an equal volume of saline (0.05 ml). At 2 hr, pinnae were measured using a micrometer caliper. We found that 1 feeding with either MDP or SDZ 280.636 abrogated IgE AFC responses and dramatically suppressed serum levels of IgE, both in isotype specific fashion, and suppressed IH responses (> 50%). 3 feedings with SDZ 280.636 also abrogated IgE AFC responses and further decreased serum levels of IgE. In contrast to SDZ 280.636, 3 treatments with MDP had opposite effects in that IgE AFC responses and serum levels of IgE dramatically increased. A single treatment with SDZ 280.636 appeared to increase serum levels of IL-6 up to three fold, while IFN gamma levels decreased. Our data suggest that SDZ 280.636 may be useful in the therapeutic and prophylactic management of human atopic disease such as allergic rhinitis, asthma, and other atopic diseases.

IgE-bearing cells and epsilon-specific mRNA in lymphoid organs of two children with AIDS.

To characterize the cellular basis of IgE responses in HIV-positive (HIV+) children, we obtained central (bone marrow [BM], thymus) and peripheral (Peyer's patches [PP], mesenteric [MLN], and other lymph nodes [OLN], spleen), lymphoid organs from two children with AIDS (females, 2 and 8 years old), and from a non-HIV-infected trauma victim (female, 5 years old) at autopsy. PP were obtained from one of the HIV+ children (2 yr old) and from the non-infected child, but no PP were detected in small intestine of the 8-yr-old HIV+ child. Numbers of lymphocytes bearing surface IgE, CD19, CD3, CD4, and CD8 in lymphoid organs were determined (flow cytometry) and evaluated for expression of epsilon-specific (E) mRNA (RT-PCR). Thymus and MLN of the HIV+ child without PP contained high numbers of IgE+ (34% and 41%, respectively) and CD19+ (32% and 28%, respectively) cells; IgE+ cells were not found in any other organ. In contrast, in the HIV+ child with PP, IgE+ cells were detected in all organs, except BM. The thymus of this child contained fewer CD19+ cells (7%). However, in both HIV+ children, all lymphoid organs, including thymus, contained E mRNA. Because numbers of IgE+ cells often far exceeded numbers of CD19+ B cells, and because CD8+ T cells predominated in all organs, some of the IgE+ cells were probably CD8+ T cells with cytophilic IgE and may include IgE-specific regulatory and/or memory T cells. IgE responses were not detected in the healthy trauma victim nor were B cells found in thymus. The data suggest that during HIV infection, IgE+ B cells may be found in thymus and that synthesis of IgE may occur in all lymphoid organs except BM.

IgE against HIV proteins in clinically healthy children with HIV disease.

Elevated serum Ige was detected in 26% (7 of 30) of children with HIV infection. The majority of children with elevated IgE were of one ethnic group (Puerto Rican) (4 of 7), compared with only 9% (2 of 23) in the normal to low IgE group (p = 0.02). Most of the children with elevated IgE had decreased circulating CD4+ T cells (5 of 7 or 71%); but none had opportunistic infections, and none failed to thrive. Although similar numbers of children with normal to low IgE had decreased circulating CD4+ T cells (19 of 23 or 83%), this group had opportunistic infections (6 of 23 or 26%) and failure to thrive (7 of 30 or 30%). There was no difference in incidence of allergic symptoms between groups. IgE antibody against HIV protein was detected by Western blot technique in the sera of three children with elevated serum IgE. Thus we have identified a group of children with HIV infection and elevated serum IgE of predominantly one ethnic group, who are without opportunistic infections or failure to thrive, some of whom produce HIV-specific IgE. This suggests that IgE may play a protective (perhaps late compensatory) role in HIV disease in genetically predisposed individuals.

Regulation of hapten-specific memory IgE responses induced in vitro. Requirement for both Thy-1+ AsGM1+ and Thy-1+ AsGM1- cells and for IFN-alpha and IL-4.

The roles of Thy-1+ and AsGM1+ spleen cells and cytokines (IL-4, IL-5, IL-6, IFN-alpha, and IFN-gamma) in regulation of hapten-specific memory IgE antibody-forming cell (AFC) responses induced in vitro were examined. BALB/c mice, injected i.p. with benzylpenicilloyl-keyhole limpet hemocyanin (BPO-KLH) (10 micrograms) on days 0 and 21, were killed on day 60 or day 120. Numbers of BPO-specific IgGI, IgE, and IgA AFC in spleen were determined by enzyme-linked immunosorbent spot assay after 0 to 6 days of culture +/- BPO-KLH. BPO-specific AFC of all isotypes were detected in spleen on day 60, but not on day 120. Day 60 AFC responses did not persist in culture in that no AFC were detected by day 2 of culture +/- BPO-KLH. When either day 60 or day 120 cells were cultured for 3 days with BPO-KLH, BPO-specific AFC responses were induced, and peaked on day 5, with similar numbers of AFC of each isotype induced with day 60 and day 120 cells. On day 60, spleen contained two subsets of Thy-1+ cells: AsGM1- (approximately 32% of total cells) and AsGM1+ (approximately 4%). Depletion and reconstitution experiments established that both subsets were required for induction of BPO-specific IgE AFC responses. Cytokines could not substitute for the Thy-1(+)-depleted cells. However, when unfractionated day 60 cells were cultured with cytokines or anti-cytokine antibodies, BPO-specific IgE AFC responses induced were both IFN-alpha and IL-4 dependent; either increased or decreased by IFN-gamma, depending on its concentration, and unaffected by IL-5 or IL-6.

Suppression of human IgE antibody forming cell responses by IL-6.

To study the effects of cytokines on human IgE antibody forming cells (AFCs), log phase U266 myeloma cells (3 x 10(3)/ml), which secrete immunoglobulin E (IgE), were cultured for 0-24 h with and without cytokine or with or without antibodies against various cytokines. The numbers of IgE AFCs were determined in ELISPOT assay. We found that interleukin-6 (IL-6) suppressed (to 95%) whereas anti-IL-6 increased (to 148%) the numbers of IgE AFCs and that both worked in a dose-dependent fashion. IL-4 and interferon-gamma (IFN-gamma) also suppressed IgE AFC responses in a dose-dependent fashion. However, antibodies to these cytokines had no effect. In contrast, IFN-alpha increased (to fourfold) the numbers of IgE AFCs in a dose-dependent fashion. The data are the first to show a suppressive effect of IL-6 on human IgE responses and may also suggest a role for IL-6 in the treatment of atopic disease.

Control of IgE responses. III. IL-6 and IFN-alpha are isotype-specific regulators of peak BPO-specific IgE antibody-forming cell responses in mice.

The ability of cytokines (IL-4, IL-5, IL-6, IFN-alpha, IFN-gamma, TNF-alpha, GmCSF) to regulate peak benzylpenicilloyl (BPO)-specific IgE antibody-forming cell (AFC) responses was investigated. These responses were induced in BALB/c mice by ip injection of BPO-keyhole limpet hemocyanin (BPO-KLH; 10 micrograms) in aluminum hydroxide gel on Days 0, 21, and 42. On Day 44, or on Days 43, 44, and 45, mice were injected sc with varying doses of cytokine or anti-cytokine antibody. On Day 46, the numbers of BPO-specific AFC (IgM, IgG1, IgE and IgA) in spleen were determined ex vivo in enzyme-linked immunosorbent spot assay. Among the cytokines tested, only IL-6 suppressed BPO-specific IgE AFC responses in an isotype-specific fashion (60-90%). However, treatment of mice with anti-IL-6 also suppressed these responses, suggesting that IL-6 can either suppress or increase peak antigen specific IgE responses, depending upon its concentration. Among the cytokines tested, only IFN-alpha increased BPO-specific IgE AFC responses in an isotype-specific fashion. Since treatment with anti-IFN-alpha suppressed these responses, it appears that IFN-alpha is required to maintain peak antigen-specific IgE AFC responses. IL-4 or IFN-gamma nonspecifically suppressed responses of all isotypes. Treatment with anti-IL-4 also suppressed IgE responses, suggesting that this cytokine is required to maintain peak antigen specific IgE responses. Treatment with anti-IFN-gamma increased IgE responses, indicating that IFN-gamma suppresses peak antigen-specific IgE responses.

[Effect of chloramphenicol and actinomycin D on extracellular alkaline RNAse biosynthesis by Bacillus intermedius]. / Vliianie khloramfenikola i aktinomitsina D na biosintez shchelochnoi vnekletochnoi RNKazy Bacillus intermedius.

By means of chloramphenicol it was found that biosynthesis of alkaline exocellular RNAase was repressed in Bacillus intermedius by inorganic phosphate. Actinomycin D at a low concentration stimulates RNAase biosynthesis in a medium with a minimal phosphorus concentration in model experiments with washed cells and in the batch culture. As a result, the activity of RNAase rises 2-4 times. The stimulating effect of actinomycin D decreases when phosphorus concentration in the medium is increased The effect of actinomycin D is maximal if the antibiotic is added to the medium when the specific growth rate of the bacterium falls down and the rate of RNAase biosynthesis rises.

[Comparative study of the antiviral activity of pancreatic and microbial RNAse]. / Sravnitel'noe izuchenie protivovirusnoi aktivnosti pankreaticheskoi i mikrobnykh RNK-az.

The efficacy of pancreatic RNase with microbial enzymes (RN-ases) of Act. rimosus and Bacillus intermedius) was studied comparatively in vitro in a transplantable cell culture of the swine embryokidney with respect to the aphthosa virus (AV) and the virus of the Aujeszky disease (VAD). The VAD proved to be most sensitive to RNases. RNase of Bac. intermedius showed the highest antiviral efficacy. The enzymes were active in vivo, when the albino mice and newborn rabbits were infected with the AV, the RNase of Bac. intermedius being also most active in this case.

[Isolation and purification of alkaline ribonuclease from Bacillus intermedius]. / Metod vydeleniia i ochistki shchelochnoi ribonukleazy Bacillus intermedius.

The paper describes a method for preparing extracellular alkaline ribonuclease from Bacillus intermedius (EC 3.1.4.23). The method consists of acid treatment of the culture fluid for selective inactivation of the interfering enzymes, concentration of the enzymic protein by ammonium sulfate precipitation, dialysis against water, chromatography on DEAE-cellulose and phosphocellulose in the steady state, rechromatography on a phosphocellulose containing column, desalting and freeze-drying of the end product. Experimental samples of ribonuclease of 92% purity have been thus obtained.

[Optimization of Bacillus intermedius cultivation conditions to increase biosynthesis of alkaline extracellular RNAase]. / Optimizatsiia uslovii kul'tivirovaniia Bacillus intermedius dlia povysheniia biosinteza shchelochnoi vnekletochnoi RNKazy.

The effect of changes in the concentrations of peptone and glucose in the growth medium, the level of aeration and the original pH value on the biosynthesis of RNAase by Bacillus intermedius 7P was studied by means of a multifactor experiment. The optimal medium for the enzyme accumulation contains from 1.2 to 1.4% of glucose and from 2.8 to 3.1% of peptone, and is characterized by the original pH value of 8.45 to 8.7 and the aeration level of 1 : 7.5. The original pH value of the medium that is optimal for the enzyme biosynthesis is not optimal for the cultural growth. Under the optimized conditions of cultivation, the RNAase activity of Bac. intermedius 7P increases by 50 to 60%.

[Ribonuclease of Bacillus intermedius 7 P. Purification by chromatography on phosphocellulose and several characteristics of the homogeneous enzyme]. / Ribonukleaza Bacillus intermedium 7 P. Ochistka khromatografiei na fosfotselliuloze i nekotorye kharakteristiki gomogennogo fermenta.

A new procedure for isolation of homogenous ribonuclease of Bac. intermedius from a commercial source is described. The yields of 140 mg of RNAse from 200 g of the enzymic powder were attained. The amino acid composition of the enzyme was determined. The RNAse contains neither the sulfhydryl groups nor the disulfide bonds and has only one histidine residue. At the same time the amount of aromatic amino acid residues is relatively high. The enzyme is highly resistant to heat and acid treatment but is less stable in an alkaline solution. The pH optimum of the RNAse for the RNA digestion is 8,5; the temperature optimum for this reaction is 37 degrees. A spectrophotometric method for the RNAse activity assay using polyA as a specific substrate was developed. The purified product provides a suitable starting material for structural studies.

[Preparation and kinetic properties of immobilized benzyl penicillin acylase]. / Poluchenie i kineticheskie svoistva priparata immobilizovannoi benzilpenitsillinatsilazy

An active insoluble preparation of immobilized benzyl penicillin acylase (IBA) EC 3.5.1.11 has been obtained by its entrapping into polyacrylamide gel lattice. Due to immobilization the preparation maintains up to 87% of its initial activity. The kinetics of IBA at low substrate concentrations obeys the Michaelis-Menten law; however, the apparent KM value decreases and the temperature optimum elevates. The inhibition by the reaction products--6-aminopenicillanic acid and phenylacetic acid--has been found to be 4.3 mM. The resultant IBA preparation proves to be suitable for hydrolysis of 5% benzyl penicillin solutions.

[Study of the conditions for mass transfer in the nystatin biosynthetic process]. / Izuchenie uslovii massoperedachi v protsesse biosinteza nistatina

The kinetics of the biomass growth, nystatin production and carbohydrate consumption in cultures of act. noursei in 180 liter fermenters was studied. Under conditions of intensive agitation (Klas greater than 6) dependence of the specific productivity on the specific rates of growth and carbohydrate consumption was found. No such dependence between the above parameters were observed under conditions of poor agitation (Klas smaller than 3.5). It was shown that at the beginning of the cultivation process the coefficient of oxygen transfer Kla rapidly decreased. Later the value of Kla decreased slightly. Dependence of the maximum activity of the culture fluid on the average coefficient of masstransfer with respect to oxygen was observed.