Absence Of Immunoglobulin Research Articles

Protracted viremia during acute sporadic hepatitis E virus infection

Background/Aims: Hepatitis E virus (HEV) is associated with epidemic and sporadic hepatitis in developing countries. The disease is largely self-limited with no long-term sequelae. The source of HEV for maintenance of the disease in an endemic area is unknown. This study investigated the occurrence and duration of viremia in patients with acute sporadic HEV infection. Methods: In 26 of 37 patients with sporadic acute non-A, non-B viral hepatitis, HEV infection was diagnosed based on positivity for immunoglobulin M anti-HEV and/or presence of viremia as shown by reverse-transcription polymerase chain reaction. In 4 patients, fecal samples were analyzed for presence of virus using polymerase chain reaction. Multiple samples were studied at varying times in 20 patients. Results: Viremia was detected in 19 of 26 patients. Two patients had viremia in the absence of immunoglobulin M anti-HEV. Four patients had protracted viremia of 45–112 days' duration. One patient showed fecal virus shedding up to the 52nd day of illness. Conclusions: Protracted viremia and prolonged fecal shedding of HEV were shown in a small group of patients. These patients may serve as temporary virus carriers responsible for continuous contamination of the sewage water.

Liposome-induced activation of the classical complement pathway does not require immunoglobulin

We have investigated the contribution of immunoglobulin to the liposome-induced activation of complement in human serum. Liposomes containing the negatively charged phospholipids cardiolipin, phosphatidylglycerol or phosphatidylinositol, in addition to phosphatidylcholine and cholesterol, were used to activate complement in a whole serum system. The contribution of immunoglobulin was studied by comparing normal human serum (NHS) to serum depleted of IgG and IgM (DDS). Using hemolytic assays of complement function, greater concentrations of phospholipids were required to activate complement in the absence of immunoglobulins. Activation of the classical pathway was confirmed using a C1q ELISA which showed that activation was dependent on the presence of C1q and confirmed that greater concentrations of phospholipids were required to activate complement in the absence of immunoglobulins. Complement activation was also assessed using crossed immunoelectrophoresis of C3 activation fragments. Using immunoblot analysis, iC3b was detected on the surface of liposomes exposed to NHS or DDS. These studies demonstrate that when liposomes, containing anionic phospholipids at an equivalent charge to cardiolipin 20 mol%, are exposed to immunoglobulin depleted serum they become opsonized by complement proteins.

Analysis of western blotting (immunoblotting) technique in diagnosis of congenital syphilis

The diagnosis of congenital syphilis in apparently healthy infants continues to be problematic. Immunoglobulin M antibodies specific for a subset of Treponema pallidum antigens have been detected by Western blotting (immunoblotting). In the present study we investigated the sensitivity and specificity of this method. We tested 26 infants aged 0 to 4 months who fulfilled the accepted criteria for the diagnosis of congenital syphilis. There were 14 symptomatic infants. Sera from 13 of these infants were positive for the 47-kDa treponemal antigen (92% sensitivity). The remaining 12 infants were clinically asymptomatic when tested at birth but subsequently displayed features consistent with the disease. Reactive blots (antibodies to the 47- and/or the 15-kDa antigens) were noted in 10 of the 12 infants (83% sensitivity). Thirty infants whose mothers had syphilis were monitored and shown to be uninfected. Nonreactive blots were seen in sera from 27 infants, while sera from 3 older infants had false-positive tests (90% specificity). The Western blotting technique is sensitive (even in the diagnosis of clinically inapparent cases) and, in the absence of immunoglobulin M rheumatoid factor, is a useful confirmatory test for congenital syphilis.

Architecture of the vir regulons of group A streptococci parallels opacity factor phenotype and M protein class.

Group A streptococci have traditionally been categorized into two broad groups based on the presence or absence of serum opacity factor (OF). Recent studies show that these two groups vary in a number of properties in addition to the OF phenotype, including sequence variations in the constant region of the antiphagocytic M protein genes, the presence or absence of immunoglobulin G Fc receptor proteins, and the presence or absence of multiple M protein-like genes situated in a tandem array. The M protein genes (emm) in OF- streptococcal strains are known to be part of a regulon of virulence-related genes controlled by the trans-acting positive regulatory gene, virR, situated just upstream of emm. In OF+ strains, however, the region adjacent to virR is occupied by an M protein-related, type IIa immunoglobulin G Fc receptor gene (fcrA), and the relative position of emm has not been determined. To further define the vir regulon in OF+ streptococci, we used the polymerase chain reaction to show that fcrA49 is situated immediately upstream of emm49 in the OF+ type 49 strain CS101. This result shows for the first time the separate identity and genetic linkage of these two genes in the vir regulon of an OF+ group A streptococcal strain and confirms our previous hypothesis that emm49 exists as the central gene in a trio of emm-like genes. Additionally, using DNA hybridizations, we found considerable sequence divergence between OF- and OF+ group A streptococci in virR and in the noncoding sequences between virR and the emm or fcrA expression site. We found, however, a high degree of sequence conservation in this region within each of the two groups of strains.

Severe combined immunodeficiency in man with an absence of immunoglobulin gene rearrangements but normal T cell receptor assembly

An autosomal recessive type of severe combined immunodeficiency disease (SCID) was characterized by an absence of immunoglobulins (Ig) in the serum and of Ig+ lymphocytes in bone barrow (BM) and peripheral blood. In the BM CD10+/terminal deoxynucleotidyl transferase-positive lymphocytes were identified. Epstein-Barr virus-transformed B lymphoblastoid cell lines (BLCL) obtained from BM and peripheral blood did not synthesize Ig. The Ig heavy and light chain gene complexes in the BLCL had retained the germ-line configuration. Mature T cells were present but their numbers in peripheral blood were decreased. T lymphoblastoid cells derived from peripheral blood expressed normal T cell receptor (TcR) CD3 complexes and manifested various genomic TcR rearrangements. It was concluded that this type of SCID entailed a complete arrest of B lymphocyte differentiation in an early stage prior to Ig rearrangements and a quantitative defect of T lymphocytes which nevertheless allowed development of mature T cells. Repeated failures of BM transplantation and the striking absence of Ig assembly suggested that this SCID defect resides in the BM microenvironment.

The evolution of inducible defence

Defences against parasites are characterized by inducible, amplifiable responses, often with a memory component. Inducible defences with similar properties are common in a variety of other types of interactions, for example many aquatic invertebrates produce inducible structural defences against their predators and competitors. Most inducible defences have the following properties: (1) a threshold of activation; (2) an amplification of response with increasing stimulus; (3) a memory component. Specificity, amplification and memory are the basis for defining a defence as 'immune' (Klein, 1982), and these properties are present in both the vertebrate and invertebrate internal defence responses to pathogens. Invertebrates differ in the absence of immunoglobulins and therefore in reduced specificity. Although the reduced specificity of invertebrate internal defence systems is often viewed as proof of their 'primitiveness', the differences in defence systems of vertebrates and invertebrates may be more related to their respective selection regimes than to phylogeny. The syngeneic recognition system of vertebrates functions to recognize small departures from self, such as would arise from neoplasia. Are vertebrates under more intense selection from neoplasia, perhaps due to a greater incidence of hormonal imbalance or hypersensitivity reactions? The invertebrate internal defence systems are all less discriminating than the vertebrate, but there are marked differences in degree of discrimination depending on whether the group is colonial or not. Even the phyla of colonial animals with quite simple body plans, the sponges and cnidarians, have a more discriminating recognition system than the phyla of solitary animals with more complex body plans, such as the molluscs and arthropods. The primary effectors of all invertebrate responses to parasites are encapsulation and phagocytosis, although in some phyla there are specific antibacterial proteins than can also be induced.(ABSTRACT TRUNCATED AT 250 WORDS)

The rate of Wallerian degeneration in the absence of immunoglobulins. A study in chick and mouse peripheral nerve

Sciatic nerves undergoing Wallerian degeneration are subject to massive invasion by monocytes bearing Fc receptors. The present experiments were done to explore the potential role of the Fc receptors. The effect of suppressed immunoglobulin levels on the rate of Wallerian degeneration was studied in the n. medioulnaris of the chick and in murine sciatic nerve. In the avian model, total immunoglobulin production was eliminated by bursectomy. The mice were injected after birth with antibodies against IgM, causing a selective reduction of immunoglobulin M levels. Myelin degeneration was measured in both groups by computer-assisted line sampling and corrected for infrafascicular edema. In both models, there were only minor differences with the controls. Immunoglobulins, accordingly, do not seem to play a significant role in the efficiency of myelin phagocytosis by monocytes during Wallerian degeneration. The study also includes data on the degree and the distribution of edema in nerves undergoing Wallerian degeneration.

Absence of immunoglobulin and T-cell receptor gene rearrangements in myelodysplastic syndromes and acute nonlymphocytic leukemias.

The arrangement of the immunoglobulin and T-cell receptor genes has been analysed in 72 cases of primary myelodysplastic syndrome and 17 cases of acute nonlymphocytic leukemia. DNA was extracted from bone marrow aspirates, digested with at least two restriction enzymes, and hybridised with probes for the joining region of the immunoglobulin heavy chain gene, the constant region of the T-cell receptor beta chain gene, and the joining region of the T-cell receptor gamma chain gene. All cases showed germline arrangements of the immunoglobulin and the T cell receptor genes. Thus, true interlineage infidelity, myeloid to lymphoid, is a rare occurrence in myelodysplasia and in myeloid leukemias.

Polymeric immunoglobulin M is secreted by transfectants of non-lymphoid cells in the absence of immunoglobulin J chain.

Plasmids were constructed in which expression of genes encoding the heavy and light chains of a hapten-specific IgM antibody is under control of a heat shock promoter. Glioma, phaeochromocytoma and other non-lymphoid cell lines transfected with the plasmids were able to process and secrete immunoglobulin following heat induction. The glioma transfectants were studied in detail and were shown to secrete polymeric IgM in a yield similar to that obtained with a plasmacytoma. However, the glioma IgM was not associated with J chain and was largely composed of pentamers and hexamers. Thus, neither J chain nor other lymphoid-specific proteins are required for assembly and secretion of polymeric IgM although the absence of J chain may encourage hexamer formation.

Rejection of bone marrow allografts by mice with severe combined immune deficiency (SCID). Evidence that natural killer cells can mediate the specificity of marrow graft rejection.

C.B-17 scid (H-2d) mice are homozygous for the gene that causes severe combined immune deficiency (SCID). These mice have no T or B cell function, yet display normal natural killer (NK) activity. Irradiated SCID mice were challenged with marrow grafts to determine if antibodies are necessary for marrow allograft rejection. SCID mice rejected H-2/Hh-1 allogeneic marrow grafts. Moreover, this rejection capability could be adoptively transferred using SCID marrow as a source of NK progenitors infused into irradiated B6 (H-2b) hosts. We conclude that NK cells can mediate marrow allograft reactivity in the absence of immunoglobulin. It follows that NK cells probably have specific receptors for Hh antigens.

Dysglobulinemic neuropathy: absence of immunoglobulin within myelin sheaths.

Dysglobulinemic neuropathy: absence of immunoglobulin within myelin sheaths.

Fulminant B Viral Hepatitis: Role of Delta Agent

The prevalence of delta-markers among 71 patients with fulminant B viral hepatitis was found to be 33.8%. The majority of the patients with delta-markers showed serologic evidence of simultaneous acute delta-infection and B viral infection. Only 5 of the 24 patients with serologic markers of acute delta-infection in this fulminant group were presumably infected chronically with hepatitis B virus as shown by the absence of immunoglobulin M antibody to hepatitis B core antigen. A study of serologic markers of acute delta-infection among 118 patients with nonfulminant acute B viral hepatitis, in contrast, revealed only 4.2% incidence. This significant difference in the prevalence of simultaneous acute B and delta viral infections between the fulminant and the nonfulminant acute hepatitis groups indicates a higher morbidity rate associated with simultaneous infection. When the fulminant group was divided into acute B viral infection without delta-markers (subgroup 1), simultaneous acute B and delta-infections (subgroup 2), and chronic asymptomatic B with acute delta-infections (subgroup 3), for comparison of survival data, the mortality rate was not significantly different in the first two groups when the patients were age matched.

Bacterial Infection and Male Infertility: Absence of Immunoglobulin A with Specificity for Common Escherichia Coli 0-Serotypes in Seminal Fluid of Infertile Men

We used an indirect solid phase radioimmunoassay to detect and quantitate immunoglobulin A (IgA) in male genital secretions with specificity for Escherichia coli (E. coli) antigen. We assayed the seminal fluid and expressed prostatic secretion (EPS) of a patient with chronic bacterial prostatitis (CBP) due to an 01 E. coli, the seminal fluid of 24 fertile men, and the seminal fluid of 62 men of infertile marriages. IgA directed apparently against the 0-antigen of the infecting E. coli was measurable in both the seminal fluid and EPS of the CBP patient. IgA in these specimens also bound to antigen in a mix of 8 common E. coli 0-serotypes that included an 01 E. coli. IgA with specificity for antigen in the mix of common E. coli 0-serotypes could not be detected in the seminal fluid of the fertile men or the men of infertile marriages. These data suggest that subclinical E. coli infections of the male reproductive tract are not commonly associated with infertility.

Semiologic value of C1q and C4 cutaneous deposits. An immunofluorescent study.

One hundred twenty skin biopsies from patients with different skin diseases were found to be positive for C3 cutaneous staining by immunofluorescence study. By the direct immunofluorescence method, we looked for C1q and C4 and immunoglobulin deposits in all those biopsies. C1q and/or C4 were only found in dermatoses with a recognised humoral immunologic mechanism; in some cases C1q and/or C4 deposits were found in the absence of immunoglobulins. The results showed that identification of C1q and C4 is important in routine immunopathologic studies, and provide interesting data of diagnostic value.

Antibody-independent classical pathway-mediated opsonophagocytosis of type Ia, group B streptococcus.

The opsonophagocytic requirements of human sera containing endogenous complement for a variety of type Ia, and group B streptococcal strains were defined. Significant reduction (>==90%) in colony-forming units was noted after a 40-min incubation for the highly encapsulated, mouse-passed prototype strain 090 by sera containing moderate to high concentrations of antibody to type Ia polysaccharide (mean, 16.5 mug/ml), whereas bacterial growth occurred in 25 sera with low levels of specific antibody (mean, 2.1 mug/ml). This absolute requirement for a critical amount of specific antibody in promoting opsonophagocytic killing of strain 090 was not found when 18 fresh clinical type Ia isolates were tested. In antibody-deficient and agammaglobulinemic sera, respectively, mean reductions in colony-forming units of 94 and 95% were seen for fresh clinical isolates, whereas strain 090 was not killed by polymorphonuclear leukocytes in the presence of these sera. All strains required a considerable amount of specific antibody for alternative pathway-mediated opsonophagocytosis. That opsonophagocytic killing of clinical type Ia isolates was mediated by the classical pathway in a nonantibody-dependent fashion was shown when MgEGTA chelation of agammaglobulinemic serum or use of serum deficient in C2 resulted in bacterial growth. The addition of C2 to C2-deficient serum restored bactericidal activity of this serum. These experiments indicate that substances other than the exposed surface of the type Ia capsular polysaccharide initiate classical pathway-mediated opsonophagocytosis of clinical isolates of type Ia, group B streptococci by human sera in the absence of immunoglobulin. Perhaps, a deficiency in classical complement pathway function is critical to the susceptibility of neonates to type Ia, group B streptococcal disease.

895 ANTIBODY-INDEPENDENT CLASSICAL PATHWAY (CP)-MEDIATED OPSONOPHAGOCYTOSIS (OP) OF TYPE Ia GROUP B STREPTOCOCCI (IaGBS)

Since invasive IaGBS disease rarely occurs beyond the early neonatal period, heat-labile serum factors rather than type-specific antibody (SpAb) could be critical to host defense against la GBS. The OP requirements for prototype strain,090, and 18 fresh clinical isolates were assessed in an assay employing human PMN, serum containing endogenous complement, and 3×106 CFU/ml of IaGBS. Significant OP of 090 (>90% reduction in CFU) occurred after 40 min. incubation in 6 sera containing high levels of SpAb, while bacterial growth was noted in 25 sera with low levels. The mean OP for 090 was compared to that for 18 clinical isolates in 3 representative sera. OP was similar in serum with high SpAb levels (94% vs 97%). However, in low SpAb and agammaglobulinemic sera, respectively, OP was 94% (range, 83-98%) and 95% (range, 77-99%) for 18 clinical isolates, while 090 grew in these sera. Absorption of serum with high SpAb with Ia polysaccharide antigen (Ag) completely inhibited OP for 090, but did not effect that for clinical isolates. All strains required high SpAb levels for alternative pathway recruitment. Serum deficient in C2 and SpAb did not promote OP of clinical isolates of IaGBS until reconstituted with C2. These findings that OP of clinical isolates of IaGBS is CP-mediated in a non-SpAb dependent fashion indicate that substances other than Ia capsular Ag, such as polar glycophospholipids, may initiate CP activation in the absence of immunoglobulin G.

Bactericidal activity of the alternative complement pathway generated from 11 isolated plasma proteins.

Exposure of E. coli K12 W1485 to the cytolytic alternative pathway assembled from the 11 isolated pathway proteins resulted in killing of the bacteria, as evidenced by loss of viability. Lysis of the bacteria required introduction of lysozyme into the reaction mixture. The time-course and dose dependency of bacteriolysis in the isolated system were identical to those in C4-depleted serum. The bacteriolytic activity of the pathway was highly dependent on the concentration of the pathway proteins and became insignificant at 1:16 physiological concentration. Electron microscopic visualization of killed and of lysed bacteria revealed numerous complement membrane lesions and partial disintegration of the outer phospholipid membrane. Scanning electron microscopy showed that killed bacteria were enlarged, partially collapsed and exhibited irregular surface protrusions. Lysed bacteria were fragmented and appeared polymorphic. This study demonstrates that the alternative pathway, in absence of immunoglobulins, has the potential or eradicating gram-negative bacteria.

The Late Phase Skin Reaction: Evidence for Activation of the Coagulation System in an IgE-Dependent Reaction in Man

Abstract The late phase reaction (LPR), an IgE-dependent sequel to the wheal and flare response (WFR), was studied in ragweed (RW)-sensitive subjects 15 min and 6 to 8 hr after intradermal RW injection. The role of WFR in the genesis of LPR and LPR dependence on RW dose were determined by skin test titration to extinction of LPR. LPR size correlated with WFR size. LPR were noted with WFR as small as 9.5 ± 1.0 mm (S.E.M.) and RW doses as small as 0.01 protein nitrogen unit (PNU). In a group of WFR-positive but LPR-negative subjects, LPR were not induced despite increasing WFR to 18.2 ± 1.3 mm by simultaneous injection of RW + histamine (RW-H). Light microscopy of 1-µm biopsy sections of direct and Prausnitz-Kustner (P-K) LPR revealed a mixed cellular infiltrate qualitatively no different than that seen 6 hr after isolated WFR. Fibrin deposition in the absence of immunoglobulin or complement was seen by fluorescent microscopy in LPR but not in controls. These data suggest that LPR may follow small RW doses. Furthermore, the failure of RW-H injection to induce LPR argues against a gatekeeper role for WFR in the genesis of LPR. The significance of the cellular infiltrate is not clear although fibrin deposition explains the clinical induration of LPR. This fibrin deposition is evidence for activation of the coagulation system in these IgE-dependent “delayed in time” reactions.

Immunocytochemical demonstration of IgG in human brain tumors (author's transl)

In the past several years a number of immunological studies of human brain tumors suggesting evidence of the existence of certain brain tumor-specific antigens have been extensively performed. However, there is other evidence that suppressive factors not only exist in the sera of patients with malignant brain tumors but also bind to lymphoid cells and that they can specifically modify the cell-mediated immune mechanisms to the tumors of the central nervous system. Therefore, humoral immunity seems to be playing an important role in the cell-mediated immune responses against brain tumors especially in relation to both antibody dependent cell-mediated cytotoxicity (ADCC) and blocking factor(s). In the present study, 23 human brain tumors (9 glioblastomas, 5 astrocytomas, 1 ependymoma, 1 medulloblastoma, 5 ineningiomas and 2 metastatic cancers) obtained at craniotomy have been examined to determine the presence or absence of immunoglobulin G (IgG) and immunoglobulin M (IgM) in the tumor tissue by the direct immunoperoxidase method using enzyme-labeled antigen binding Fab' fragments. Of 23 human brain tumors examined, 3 glioblastomas, I ependymoma, 1 medulloblastoma, 5 meningiomas and 1 metastatic cancer displayed unequivocally positive immunocytochemical reaction for IgG in the tumor tissue. The intensity of staining differed among the tumor cells and IgG was mainly localized on the surface of the tumor cells by immunoelectron microscopy. On the other hand, IgM was not observed in any tumor tissues except for the positive staining limited within the capillary lumen of the tumors. In the meningiomas, the positive staining for IgG was more prominent around the capillaries, psammoma bodies and in the whorl formation, suggesting possible contribution of humoral immune reaction in the mechanisms of whorl or psammoma body formation. Although it is not clear as to whether or not IgG distributed on the surface of tumor cells acts to suppress or accelerate cellular immunity and complement-dependent cytolysis of tumor cells in vivo, our present immunocytochemical findings suggest tumor-specific antibodies among IgG “coating” on the cells of certain human brain tumors.

Immunopathology of membranoproliferative glomerulonephritis with subendothelial deposits (Type I MPGN)

Immunofluorescence microscopy (IF) studies were carried out in 36 patients with Type I MPGN and showed the constant presence of deposits containing C3. Based on the presence or the absence of immunoglobulins (Ig), two main patterns were observed. Complement profiles (30 patients) and C3NeF activity (20 patients) were studied in the two groups defined by IF. Our findings indicate an activation of the complement system through the classical pathway even in the group characterized by the absence of Ig. Such an activation suggests the role of immune complexes in the pathogenesis of the disease. Because of the presence of C3NeF activity in occasional patients, a superimposed activation through the alternative pathway is not unlikely. In two additional patients, one with predominant IgA within the deposits and one with C2-deficiency, the complement system is probably activated through the alternative pathway.