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IgE was isolated from a patient with the hyper IgE, recurrent infection syndrome by immunoadsorption on sepharose bound goat anti-human IgE. Addition of this IgE to a monolayer culture of human monocytes resulted in a dose-dependent increase in PGE2 secretion. The addition of F(ab')2 fraction of goat anti-human IgE in the presence of sub-stimulating doses of IgE markedly increased PGE2 secretion; whereas addition of F(ab')2 fragment of irrelevant goat IgG had no effect. Similar activation of monocytes which could be enhanced by anti IgE was observed in the presence of the patient's serum. No such effect was seen in the presence of normal human serum. These results indicate that IgE may activate human monocytes and induce PGE secretion. [ABSTRACT FROM AUTHOR]

Ajax mice fed a diet with a reduced proportion of protein, cleared carbon more slowly, and produced less antibody of lower affinity, when immunized with human serum transferrin (HST) in saline than did normally fed controls. This finding is discussed in terms of the defective antibody response in protein-malnourished children, and the possible contribution such environmental factors may have on immunopathological and neoplastic effects of infection. [ABSTRACT FROM AUTHOR]

Macrophage function, as measured by carbon clearance, differs in different inbred strains. Low affinity (KR) antibody response to HST is associated either with poor carbon clearance, or slow recovery from carbon blockade by macrophages. Carbon blockade reduces KR, but not Abt, in mice with high carbon clearance and KR. Stilboestrol increases carbon clearance and KR in mice with slow clearance and low KR. The significance of these findings in pathogenesis and treatment of chronic soluble complex disease is discussed. [ABSTRACT FROM AUTHOR]

The effects of concanavilin A (Con A)-induced lymphokines from human peripheral blood mononuclear cells, enriched helper and suppressor lymphocyte populations and recombinant interferon-gamma (IFN-gamma) on the ability of monocytes to promote killing of intracellular Leishmania major (L. major) amastigotes and to induce the production of hydrogen peroxide (H2O2) was examined. All these mitogen-induced supernatants contained active IFN-gamma. There were no differences in the ability of these supernatants or IFN-gamma to promote the monocyte killing of the L. major amastigotes or H2O2 production. An increase in H2O2 production by monocyte monolayers was observed following the addition of either of these supernatants or IFN-gamma alone. In addition, a marked increase in the production of H2O2 was observed following priming with either of these mitogen-induced supernatants or IFN-gamma and the addition of a second stimulus, phorbol myristate acetate (PM A). Monoclonal antibody to IFN-gamma abrogated the increase in production of H2O2 by all these mitogen-induced supernatants; however, this antibody only resulted in partial inhibition of the leishmaniacidal effect of these lymphokines on human monocytes. These results would suggest that IFN-gamma is the component of the lymphokine that is largely or exclusively responsible for H2O2 production, while other factors in addition to IFN-gamma are important in promoting oxygen-independent mechanisms for the killing of intracellular L. major amastigotes. [ABSTRACT FROM AUTHOR]

Human monocytes suppressed both the phytohaemagglutin (PHA) or antigen-induced lymphocyte proliferative response, when the monocyte: lymphocyte ratio was increased or when the monocytes were stimulated with zymosan or endotoxin. The effect of monocytes on autologous lymphocyte proliferation was compared with that of macrophages obtained by culturing monocytes in vitro for 7 days. The lymphocyte proliferative responses were increased in the presence of macrophages, however, neither increasing their number nor stimulation by zymosan or endotoxin altered the autologous lymphocyte proliferative response to PHA or purified protein derivative (PPD). The PGE2 concentration in the medium of both the cultured monocytes or macrophages activated by zymosan and endotoxin rose markedly without a corresponding suppressor effect on lymphocyte proliferation in the presence of macrophages in the culture. Thus it seems that while PGE2 is a useful marker of mononuclear phagocyte activation, other molecular species are of importance in determining the lymphocyte proliferative response to mitogens and antigens. [ABSTRACT FROM AUTHOR]

Exposure of human monocytes in monolayer culture to concanavalin A (Con A) or Fc fragments of IgG results in decreased levels of lysozyme, acid phosphatase and the second component of complement (C2), but increased levels of prostaglandin E2 (PGE2) in the culture medium. Indomethacin blocked the effect of Con A and Fc fragments on PGE2 levels but did not alter the effects on the other secretory products. The addition of Con A to the monocyte cultures resulted in increased cAMP levels in short (< 20 min) and in long term incubations (24 hr). Long term exposure to the Fc fragments of IgG also resulted in elevated levels of cAMP. In long term cultures, elevation of cAMP levels by Fc fragments and Con A may in part be mediated by stimulation of endogenous prostaglandin production, since addition of indomethacin resulted in a return of cAMP towards basal levels. The addition of D-L isoproterenol, IBMX, or exogenous PGE2, reagents that increase cAMP content, or addition of Dibutyryl 3′, 5′ adenosine monophosphate (DBcAMP) to cultures resulted in a dose-dependent inhibition of secretion of acid phosphatase, lysozyme and C2. These findings suggest that certain secretory responses of human monocytes are reduced by agents which increase cAMP levels. These changes may be related to direct effects on adenylate cyclase stimulation or indirect effects on the release of other products which effect cAMP generation. These changes in cAMP content may in part be responsible for the reduced secretory response. [ABSTRACT FROM AUTHOR]

Human monocytes were maintained in tissue culture and the effect of various stimuli on their morphology and capacity to synthesize and secrete total protein, lysozyme, acid phosphatase, prostaglandin E and the second component of complement were determined. Human monomeric IgG, Fab fragments and albumin had no effect on the secretion of these products. However, addition of Fc fragments significantly decreased the synthesis of both lysosomal enzymes and the second component of complement and increased production of prostaglandin E. The addition of Con A to the monocyte monolayers resulted in a similar response. Latex particles slightly increased the secretion of acid phosphatase and C2, but had no effect on lysozyme secretion. Fc fragments also stimulated protein synthesis by monocyte monolayers cultured in serum-free medium. These ‘activators’ and endotoxin- or antigen-activated mononuclear cell supernatants (AMNS) resulted in varying degrees of increased spreading and adherence of the monocytes. The results of these studies suggest that the molecular species inducing the ‘activated state’ qualitatively and quantitatively determines the characteristics of the secretory response. [ABSTRACT FROM AUTHOR]

The binding of sensitized red cells to Fc receptors in human monocytes was studied by evaluating the effects of various pharmacological reagents and other treatments on EA rosette formation. Cytochalasin B and 2-deoxyglucose inhibited rosette formation in a dose-dependent manner. Sodium azide and incubation at 4° also inhibited rosette formation, while at 37° increased numbers of RBCs bound to the monocytes. The microtubular poisons, vinblastine and colchicine at high concentrations resulted in decreased adherence of monocytes and inhibition of rosette formation, while at low concentrations of colchicine, enhanced rosette formation was sometimes observed. Contrary to the effects on rosette formation, binding of [125I] IgG to monocyte monolayers was not altered by treatment of the monocytes with drugs. Magnesium ions were required to promote monocyte adherence, but both magnesium and calcium were needed for the best rosette formation. We conclude that the formation of EA rosettes is dependent not merely on binding of IgG to the Fc receptor but requires metabolically active monocytes, an intact cytostructure and suitable environmental conditions (temperature and cation concentration). [ABSTRACT FROM AUTHOR]

The deposition of complement in the kidney mesangium is a constant finding associated with renal injury in IgA nephropathy, even though IgA does not bind complement. We have previously reported that complement gene expression in the kidney increases concurrently with the progression of immune complex disease in murine lupus nephritis. We have now studied the expression of C3, C4, factor B and HLA-DRα mRNA by in situ hybridization in renal biopsy specimens of patients with IgA nephropathy and compared these findings to those in patients with other immune-mediated diseases of the kidney, hereditary nephritis and normal kidney. In IgA nephropathy, C3 and factor B mRNA were expressed in the renal tubular epithelial cells, while no expression of either C3 or factor B mRNA was apparent in the glomerulus. Specimens from patients with other immune-mediated forms of chronic glomerulonephritis also showed a similar pattern of expression of C3 and factor B mRNA only in the tubules, but not in the glomerules. However, C3 and factor B mRNA were not found in normal kidney tissue or biopsy specimens from patients with hereditary nephritis. C4 mRNA was expressed in the tubular epithelial cells in all specimens examined, indicating that C4 mRNA is constitutively expressed in the human kidney. In IgA nephropathy HLA-DRα mRNA was observed in the interstitium, but not the tubules or glomerular cells. In contrast, HLA-DRα mRNA was present in the glomerulus and scattered in the interstitium in other immune-mediated kidney diseases. There was no expression of HLA-DRα mRNA in hereditary nephritis or normal kidney. Our findings, which reflect the immunopathogenic events in vivo, provide new insights as to the interpretation of the molecular immunology of this immune complex disease. [ABSTRACT FROM AUTHOR]

We have studied the effect of IgA- and IgG-containing immune complexes on the production of complement proteins C3, factor B and C2 by human monocyte-derived macrophages, using biosynthetic labelling, immunoprecipitation, sodium dodecyl sulphate-polyacrylamide gel (SDS-PAGE) and autoradiography. There was a consistent increase in C3 production and secretion with both IgA and IgG immune complexes. This increase appeared after a 24-hr incubation period of the macrophages in the presence of immune complexes. No change in the biosynthesis of factor B and C2 proteins was observed in these experiments. Concomitant with the enhanced C3 biosynthesis, the immune complexes caused an increase in macrophage tumour necrosis factor (TNF) production; 310 + 24 U/ml/5 × 105 cells and 430 + 51 U/ml/5 × 105 cells for IgA and IgG immune complexes, respectively, venus 12 + 8 U/ml/5 × 105 cells in the control cells. The presence of prednisolone (2 × 10-5 M) or dexaniethasone (1 × 10-7 M) inhibited the immune complex-induced TNF production, but had no effect on C3-increased synthesis, suggesting that the effect of immune complexes was not mediated by endogenous TNF production. These findings may be relevant to the local inflammatory response in IgA immune complex-mediated diseases, including IgA nephropathy. [ABSTRACT FROM AUTHOR]

Humoral and cell-mediated responses to crude and purified parasite antigens were examined in patients with active cutaneous leishmaniasis caused by Leishmania major. The patients had serum antibody titres against parasite lysates ranging from 1/500 to 1/10 000 and recognized multiple components by Western blotting with molecular weights between 5000 and > 200 000. Several components, particularly at 5 and 50 kD, were recognized by most of the patients. The lymphoproliferative responses to two pure antigens, promastigote surface protease and lipophosphoglycan, both considered potential candidates for the development of a human vaccine were measured. No response to promastigote surface protease was observed even at 10 μg/ml; however, weak proliferation to lipophosphoglycan was consistently present. T cell blots examining peripheral blood lymphocyte proliferation, showed antigen-specific responses to a 72-82 kD component in promastigote lysates. [ABSTRACT FROM AUTHOR]

Unlabelled: A 4-y-old girl was admitted because of a left leg limp with an isolated swollen upper thigh and normal muscle enzymes. A radioisotope scan showed increased uptake especially in the bone and soft tissue of the left thigh, while magnetic resonance imaging of that region demonstrated widespread oedema in striated muscle. On muscle biopsy perivascular infiltrates were demonstrated but muscle fibres were not shown to be affected. Sequence analysis of reverse transcription-polymerase chain reaction amplified fragments from the 5'-non-coding region of human enteroviruses identified a local strain of coxsackie virus A21 in the muscle. Clinical symptomatology subsided with oral steroids.Conclusion: Local swelling mimicking a neoplasm may be related to infestation of coxsackie virus in muscle tissue. [ABSTRACT FROM AUTHOR]

In 2 infants who had received Intralipid fat emulsion as part of a total parenteral hyperalimentation regimen, a pigmented material was deposited in the macrophages of their reticuloendothelial systems. The histochemical characteristics of this pigment were similar to those seen after experimental infusion of fat emulsions. The possible implications of this finding and its effect on host resistance are briefly considered. [ABSTRACT FROM AUTHOR]

Data suggest that the O-specific polysaccharide (O-SP) domain of the lipopolysaccharide (LPS) of Shigella species is both an essential virulence factor and a protective antigen and that a critical level of serum immunoglobulin G (IgG) to this antigen will confer immunity to shigellosis. Because covalent attachment of polysaccharides to proteins increases their immunogenicity, especially in infants and in young children, the O-SP of Shigella species were bound to medically useful proteins, and the safety and immunogenicity of the resultant conjugates were confirmed in adults and 4- to 7-year-old children. Succinylation of the carrier protein improved the immunogenicity of Shigella conjugates in mice and increased their yield. Based on these results, a clinical trial of O-SP conjugates of Shigella sonnei and Shigella flexneri 2a bound to succinylated mutant Pseudomonas aeruginosa exotoxin A (rEPAsucc) or native or succinylated Corynebacterium diphtheriae toxin mutant (CRM9 or CRM9succ) was conducted in healthy adults. The conjugates were safe and immunogenic. S. sonnei-CRM9, S. sonnei-CRM9succ, and S. sonnei-rEPAsucc elicited significant rises of geometric mean (GM) IgG anti-LPS within 1 week of injection (P < 0.001). At 26 weeks, the GM anti-LPS levels elicited by these three conjugates were similar and higher than their prevaccination levels (P < 0.0001). GM IgG anti-LPS levels elicited by S. flexneri 2a-rEPAsucc were significantly higher than those elicited by S. flexneri 2a-rCRM9succ at all intervals after injection. At 26 weeks, the levels of IgG anti-LPS in vaccinees were higher than their prevaccination levels (P < 0.0001). The serum antibody responses were specific, as there was no significant rise of anti-LPS to the heterologous O-SP in any vaccinee. Both conjugates elicited statistically significant rises of serum antibodies to the injected carrier protein. At 6 months, these five Shigella conjugates elicited higher fold rises than similar conjugates (D. N. Taylor et al., Infect. Immun. 61:3678-3687, 1993). Based on these data, we chose S. sonnei-CRM9 and S. flexneri 2a-rEPAsucc for evaluation in children.

Objective: To determine the factors predisposing to Pseudomonas aeruginosa bacteremia as well as the prevalence, source of infection, outcome and prognostic factors in pediatric patients., Methods: Retrospective review of pediatric patients with P. aeruginosa bacteremia, at a large tertiary care hospital during a 6.5-year period., Results: Seventy patients with P. aeruginosa bacteremia were identified. The annual rate of P. aeruginosa bacteremia remained unchanged during the study period. Antibiotic susceptibility remained unchanged except for two patients with extensive burns who developed resistant strains. Underlying diseases were malignancy (50%), prematurity (6%), burns (7%) and others (37%). The overall mortality associated with P. aeruginosa bacteremia was 20%. The fatality rate was higher among the young infants (compared with older children) and those who received previous antibiotic therapy (P = 0.02). Mortality rate was higher in nosocomial than in community-acquired infections (25% compared with 11.5%). The mortality rate of low birth weight and burns patients was significantly higher when compared with oncology patients or other patients, 75 and 40% compared with 11 and 19%, P = 0.01. Multiple regression analysis revealed a correlation only between the underlying disease and mortality (P = 0.02). In the oncology patients the only significant risk factor for mortality was absolute neutrophil count < or =0.1 x 10(9)/l (P = 0.06)., Conclusion: P. aeruginosa bacteremia, although apparently not increasing in incidence and antibiotic resistance, is still a common serious complication in immunocompromised children with a high mortality rate. We conclude that the underlying disease is the main determinant of the clinical outcome.

Background: We have recently demonstrated that human fetal renal tissue, implanted under the kidney capsule of severe immunodeficient rats, escapes early destruction by intraperitoneal infusion of allogeneic human peripheral blood mononuclear cells, compared with the rapid rejection of implants of human adult kidney tissue. Variable amounts of human mononuclear infiltrates were seen in the transplanted fetal kidney, however, prolonged survival of the fetal tissue (maintenance of graft architecture and significant growth) was independent of the cellular infiltrate., Methods: We have used this experimental model to sequentially analyze transcript levels of interferon-gamma and interleukin (IL)-2 (T helper 1 cytokines), IL-4 and IL-10 (T helper 2 cytokines), RANTES, MIP1beta (beta chemokines) and their receptor CCR5, and Fas ligand (cytolytic effector molecule). Analysis was performed by reverse transcriptase-polymerase chain reaction, in both fetal and adult kidney grafts, after infusion of allogeneic human peripheral blood mononuclear cells., Results: Transcript levels of interferon-gamma and IL-2 in the fetal grafts were markedly reduced throughout follow-up, compared with those observed in the adult implants. Peak levels of these cytokines appeared late in the rejection process. Concomitant with these findings, IL-4 mRNA was up-regulated during the early phase, whereas IL-10 mRNA persisted throughout the rejection process, indicating that a T helper 2 bias occurred in the fetal grafts. In addition, RANTES (after an early peak), MIP1beta, CCR5, and Fas ligand mRNA levels were suppressed in the fetal grafts compared with those in the adult grafts., Conclusions: These findings indicate that the immune response of kidney rejection is dependent on whether the target organ is of fetal or adult origin, and suggest that an allogeneic immune system mounts a T helper 2-biased response when the target organ is of fetal origin.

Complement components in breast milk may enhance the local immune response in the gut of infants. In this study, we investigated the expression of complement genes in the mammary gland and attempted to determine possible regulatory mechanisms. We have studied the expression of C3, C4, factor B, and HLA-DRalpha mRNA by in situ hybridization in gestational mammary gland specimens and compared these findings to those in breast tissue affected with an inflammatory process, lactating adenoma or idiopathic gynecomastia. In normal resting breast, only C4 mRNA was noted in some ductal epithelium. In gestational mammary gland, there was a diffuse expression of C4, C3, and factor B mRNA in the epithelial cells of the acini. A similar pattern of complement gene expression was found in localized areas of an infectious inflammatory process. In addition, in the inflammatory specimens, there was also expression of C3 mRNA in infiltrating macrophages (CD 68 positive cells). In gynecomastia, C4 mRNA was noted in ductal epithelium, and there was a marked increased expression of C3 mRNA in the proliferating epithelium of the lactating adenoma. HLA-DRalpha was observed only in macrophages involved in the inflammatory response. Our findings, which reflect the hormonal and inflammatory events in vivo, provide new insights as to in situ complement gene expression.

We report 28 patients (20 male) with a syndrome characterized by abrupt onset of fever, malaise, aphthous stomatitis, tonsillitis, pharyngitis, and cervical adenopathy (PFAPA syndrome). Episodes of fever occurred at intervals of 5.1 +/- 1.3 weeks beginning at the age of 4.2 +/- 2.7 years. Fever, malaise, tonsillitis with negative throat cultures, and cervical adenopathy were reported in all 28 patients, aphthae in 19, headache in 5, abdominal pain in 5, and arthralgia in 3. Mild hepatosplenomegaly was observed in 6 patients. Mild leukocytosis, elevation of the erythrocyte sedimentation rate, and fibrinogen were found during attacks. These episodes of illness resolved spontaneously in 4.3 +/- 1.7 days. Serum IgD was found elevated (>100 U/mL) in 12 of the 18 patients tested (140.2 +/- 62.4 U/mL). Affected children grow normally, have no associated diseases, and have no long-term sequelae. Attacks were aborted by a single dose of oral prednisone (2 mg/kg) at the beginning of the attack in all 15 patients in whom this medication was prescribed. In 9 patients the syndrome has completely resolved (beginning at the age of 2.9 +/- 1.3 and lasting 8 +/- 2.5 years). In 3 other patients complete resolution of the attacks occurred after tonsillectomy was performed. PFAPA is sporadic, and no ethnic predilection was found. Increased awareness of the clinical syndrome has resulted in more frequent diagnosis and adequate treatment.

O-specific polysaccharide conjugates of shigellae were safe and immunogenic in young adults, and a Shigella sonnei conjugate conferred protection [1-3]. Shigellosis is primarily a disease of children; therefore, the safety and immunogenicity of S. sonnei and Shigella flexneri 2a conjugates were studied in 4- to 7-year-old children. Local and systemic reactions were minimal. The first injection of both conjugates elicited significant rises in geometric mean levels of serum IgG only to the homologous lipopolysaccharide (LPS) (S. sonnei, 0.32-8.25 ELISA units [EU]; S. flexneri 2a, 1.15-20.5 EU; P<.0001). Revaccination at 6 weeks induced a booster response to S. flexneri 2a LPS (20.5-30.5 EU, P=.003). Six months later, the geometric mean levels of IgG anti-LPS for both groups were higher than the prevaccination levels (P<.0001). Similar, but lesser, rises were observed for IgM and IgA anti-LPS. The investigational Shigella conjugates were safe and immunogenic in children and merit evaluation of their efficacy.