Number Of Immunoglobulin-secreting Cells Research Articles

CD4+ T Cell Dependent B Cell Recovery and Function After Autologous Hematopoietic Stem Cell Transplantation.

IntroductionHigh-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HSCT) represents a standard treatment regime for multiple myeloma (MM) patients. Common and potentially fatal side effects after auto-HSCT are infections due to a severely compromised immune system with hampered humoral and cellular immunity. This study delineates in depth the quantitative and functional B cell defects and investigates underlying extrinsic or intrinsic drivers.MethodsPeripheral blood of MM patients undergoing high-dose chemotherapy and auto-HSCT (before high-dose chemotherapy and in early reconstitution after HSCT) was studied. Absolute numbers and distribution of B cell subsets were analyzed ex vivo using flow cytometry. Additionally, B cell function was assessed with T cell dependent (TD) and T cell independent (TI) stimulation assays, analyzing proliferation and differentiation of B cells by flow cytometry and numbers of immunoglobulin secreting cells in ELISpots.ResultsQuantitative B cell defects including a shift in the B cell subset distribution occurred after auto-HSCT. Functionally, these patients showed an impaired TD as well as TI B cell immune response. Individual functional responses correlated with quantitative alterations of CD19+, CD4+, memory B cells and marginal zone-like B cells. The TD B cell function could be partially restored upon stimulation with CD40L/IL-21, successfully inducing B cell proliferation and differentiation into plasmablasts and immunoglobulin secreting cells.ConclusionQuantitative and functional B cell defects contribute to the compromised immune defense in MM patients undergoing auto-HSCT. Functional recovery upon TD stimulation and correlation with CD4+ T cell numbers, indicate these as extrinsic drivers of the functional B cell defect. Observed correlations of CD4+, CD19+, memory B and MZ-like B cell numbers with the B cell function suggest that these markers should be tested as potential biomarkers in prospective studies.

Oral tolerance correlates with high levels of lymphocyte activity

Oral tolerance is defined as an inhibition of specific immune responsiveness to a previously ingested antigen. Paradoxically, we found an increased lymphocyte activity in tolerant mice alongside the specific inhibition. Orally-tolerant mice presented higher number of immunoglobulin secreting cells (ISC) in spleen and bone marrow; showed a greater variety of Ig classes being produced: IgM and IgA in the spleen and IgG and IgM in the bone marrow. ISC from immunized mice produced mainly IgG. Despite having the same number of regulatory and activated T cells in the spleen after immunization, these cells appeared earlier in tolerant mice, right after the primary immunization. Also, tolerant mice showed a prompt expression of regulatory cytokines (TGF-β and IL-10) and a transient expression of effector cytokines (IL-2 and IFN-γ). Thus, in addition to an inhibited specific responsiveness, orally-tolerant mice displayed an early and widespread mobilization of activated and regulatory lymphocytes.

Pathogen-Specific Circulating Plasmablasts in Patients with Pneumonia

Lower respiratory tract infections (LRTI) are the leading cause of death world-wide, with Streptococcus pneumoniae (Pnc) as the most prevalent pathogen. Local immune mechanisms appear central to protection against the disease, yet they are poorly characterized. Infections at other, non-respiratory mucosal sites are associated with a transient circulation of mucosa-originating lymphocytes from the mucosal site to blood and back to the mucosa. The present study explored whether pathogen-specific plasmablasts appear in the circulation also in patients with infection of the lower respiratory tract. 16 patients with bacteremic Pnc pneumonia and 14 healthy volunteers were explored for circulating plasmablasts secreting antibodies against their own pathogenic Pnc strain isolated in blood cultures (patients) or against several pathogenic strains from pneumonia patients (14 controls) or a mixture of nine different purified pneumococcal polysaccharides (8 controls). Both patients and volunteers were studied for all plasmablasts. The cells were identified with ELISPOT as Pnc-specific antibody-secreting cells (ASC) and as all immunoglobulin-secreting cells (ISC). High numbers of circulating Pnc-specific ASC were found in the acute phase of the disease in all patients with pneumonia (median 97 ASC/106 PBMC), but in none of the controls. IgG isotype predominated in 9/16 patients. The numbers of ISC were significantly higher in the patients than in the healthy controls, yet Pnc-specific ASC only accounted for 0.7% of all the patients' ISC.The present study is the first to show that antigen-specific plasmablasts appear in the circulation in pneumonia, suggesting that pulmonary lypmhocytes recirculate in humans. Assessing these cells provides a novel tool for studying immune response to antigens encountered at the LRT.

Helicobacter pylori induces lymphocyte activation in peripheral blood cultures

Helicobacter pylori-induced in vitro stimulation of mononuclear cells was characterized by measuring DNA synthesis response, interferon-gamma (IFN-gamma) secretion and the number of immunoglobulin-secreting cells. The strength of these responses was measured in 51 subjects comprising 36 dyspeptic patients from the Gastroenterological Unit and 15 members of the laboratory staff. Nineteen subjects had antibodies to H. pylori and 32 did not. The responses were compared with respect to H. pylori antibody status. Positive stimulation of DNA synthesis (stimulation index greater than 2) was obtained in 96% of the subjects, and the bacterium induced IFN-gamma secretion in all of them. The induction of immunoglobulin-secreting cells revealed B cell in vitro stimulation. The antibody-positive subjects had a tendency to synthesize less DNA (P not significant) and secrete less IFN-gamma (P less than 0.05) in response to H. pylori than did the antibody-negative ones, but the differences were not marked. The results show that the whole H. pylori bacterium stimulates mononuclear cells. The nature of the stimulation is not yet characterized (non-specific versus specific).

Effects of Short- and Long-Term Ultraviolet B Irradiation on the Immune System of the Common Carp (Cyprinus carpio)

Carp (Cyprinus carpio) were repeatedly exposed to 0, 60, 120 and 240 mJ/cm2 ultraviolet B (UVB) radiation three times in 1 week (short-term exposure) or 12 times in 4 weeks (long-term exposure). The effect of UVB on the functioning of the carp immune system was studied on day 2 after the final irradiation. After short-term UVB exposure, the whole-blood respiratory burst and cytotoxic activity were markedly enhanced, with parallel responses in both the number of circulating granulocytes and in the plasma cortisol concentration of the fish. These changes were not detectable after long-term exposure. The respiratory burst by head kidney granulocytes was suppressed dose dependently after both exposures, but cytotoxic activity was not affected. Exposure to UVB also modulated lymphocyte functions: nonstimulated and PHA-stimulated proliferation of head kidney lymphocytes in vitro was enhanced by both short-term and long-term exposure. LPS-stimulated proliferation was not affected by exposure nor was the number of immunoglobulin-secreting cells in the head kidney. In long-term exposure, the highest dose reduced the level of plasma IgM. This study indicates that UVB irradiation induces immunomodulation in the blood and head kidney of the carp and that the effects of short- and long-term exposure differ from each other. The results emphasize the potentially harmful impact of increased solar UVB radiation on fish immune functions.

Effects of Short- and Long-term Ultraviolet B Irradiation on the Immune System of the Common Carp (Cyprinus carpio)¶

Carp (Cyprinus carpio) were repeatedly exposed to 0, 60, 120 and 240 mJ/cm2 ultraviolet B (UVB) radiation three times in 1 week (short-term exposure) or 12 times in 4 weeks (long-term exposure). The effect of UVB on the functioning of the carp immune system was studied on day 2 after the final irradiation. After short-term UVB exposure, the whole-blood respiratory burst and cytotoxic activity were markedly enhanced, with parallel responses in both the number of circulating granulocytes and in the plasma cortisol concentration of the fish. These changes were not detectable after long-term exposure. The respiratory burst by head kidney granulocytes was suppressed dose dependently after both exposures, but cytotoxic activity was not affected. Exposure to UVB also modulated lymphocyte functions: nonstimulated and PHA-stimulated proliferation of head kidney lymphocytes in vitro was enhanced by both short-term and long-term exposure. LPS-stimulated proliferation was not affected by exposure nor was the number of immunoglobulin-secreting cells in the head kidney. In long-term exposure, the highest dose reduced the level of plasma IgM. This study indicates that UVB irradiation induces immunomodulation in the blood and head kidney of the carp and that the effects of short- and long-term exposure differ from each other. The results emphasize the potentially harmful impact of increased solar UVB radiation on fish immune functions.

Cellular requirements for immunomodulatory effects caused by cell wall components of Paracoccidioides brasiliensis on antibody production.

In a previous study, we reported an increase in the number of immunoglobulin-secreting cells and the augmentation of antibody production (IgM and IgG3) against unrelated antigens (sheep erythrocytes or bovine serum albumin (BSA)) in mice infected with the fungus Paracoccidioides brasiliensis as well as in mice inoculated with its cell wall preparation (CW). The immunomodulatory effect of the live fungus and CW preparation was dose-dependent and mainly restricted to the i.p. inoculation simultaneously to the BSA challenge by the i.v. route. In the present study, we investigated the active component of CW preparation upon the phenotype and also the degree of activation of possible target peritoneal cells involved in those phenomena. An insoluble polysaccharide fraction (F1 fraction) mainly composed of beta-glucan and chitin, and the purified beta-glucan (BGPb) behaved as CW in the augmentation of early antibody production. The peritoneal mononuclear inflammatory cells induced by CW, F1 fraction and BGPb were highly positive to alpha-naphthyl esterase staining; released low H2O2; expressed high levels of MHC-Ia(d) molecules and produced inflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha) and IL-6. Phenotypic analysis by flow cytometry and immunohistochemical techniques of the inflammatory cells responding to F1 fraction showed a prevalence of (CD11b/CD18, Mac-1)+ peritoneal macrophages. In addition, s.c. inoculation of F1 fraction resulted in the formation of nodular, localized and not progressive granulomatous lesions with an accumulation of (CD11b/C18)+ macrophages. Adoptive transferred Mac-1 macrophages to immunized syngeneic recipient mice were able to cause an increase in anti-BSA antibody production. These results suggest that inflammatory (CD11b/CD18)+ macrophages may be related to immunological disturbances, caused by cell wall components of P. brasiliensis.

Early development of immune system in pigs

Prenatal and early postnatal immune system development has been studied in minipigs. First leukocytes were observed in the yolk sac and fetal liver (FL) on the 17th day of gestation, the majority of them being SWC3 +. The colonization of the thymus (TH) with leukocytes was observed 21 days later. Two waves of fetal TH colonization with pro-T cells were deduced from the frequency of thymocyte subsets. Thymic B cells and immunoglobulin-secreting cells (Ig-SC) were studied by flow cytometry and ELISPOT, respectively. When the total numbers of fetal Ig-SC were compared, the TH was identified as the main source of natural antibodies and the only site of IgA and IgG synthesis. In germ-free animals, the TH also represented the major site of IgG and IgA production and the number of Ig-SC was not influenced by colonization with microflora. FL and bone marrow were identified as primary B lymphopoietic sites. The phenotype of B precursors was characterized and pre-B II cells were shown to be the dominant mononuclear fraction between DG50 and DG105. In the periphery, relative proportions of lymphocyte subsets were determined. Studies in gnotobiotic piglets have revealed that the appearance of CD4 +CD8 + T cells and CD2 − B cells is absolutely dependent on the contact of immune system with live viruses and bacteria, respectively.

Effects of primary- and secondary-treated bleached kraft mill effluents on the immune system and physiological parameters of roach

The present study was designed to examine, whether, effluents from a modern pulp and paper mill using elemental chlorine-free/total chlorine-free (ECF/TCF) bleaching, exert effects on the immune system of fish and, in addition, to relate these findings to physiological parameters known to be affected by bleached kraft-mill effluents (BKME). Roach ( Rutilus rutilus) were exposed in laboratory conditions to primary- or secondary-treated effluent from a pulp and paper mill. In order to study their capability to respond to foreign antigens they were immunised with bovine γ-globulin (BGG) prior to exposure. The number of anti-BGG antibody-secreting cells (ASC) and the number of immunoglobulin-secreting cells (ISC) in the spleen and blood as well as the level of anti-BGG specific antibodies and concentration of plasma immunoglobulin (IgM) were studied. Phagocytosis and migration of granulocytes of the head kidney were also determined. In addition to the immunological parameters, the activity of hepatic biotransformation enzymes, the carbohydrate metabolism and osmoregulation were examined. Exposure of roach for 21 days to BKME affected several immunological parameters. Both effluents, primary- and secondary-treated, impaired the immunoreactivity of the fish. Sex-related differences in the immune responses were evident in many parameters e.g. in the number of blood ISC and splenic ASC. Sex also had effects on cortisol levels and in the induction of 7-ethoxyresorufin O-deethylase (EROD). These results demonstrate that both primary- and secondary-treated effluent from a pulp and paper mill using ECF/TCF bleaching have effects on fish immune functions. Further, these findings suggest that steroids may contribute to immunomodulation in fish.

CAESAREAN SECTION DELIVERY IS ACCOMPANIED WITH DEFECTIVE CAPACITY TO GENERATE IGA IN NEONATES

63 AIM Microbial antigens preferentially expand T helper 1-type cells and thereby provide optimal conditions to redirect the immunologic memory away from the T helper 2-type phenotype of atopy. Caesarean section delivery interferes with the development of normal intestinal microflora which contribute to the development of mucosal immunity in the gut. This study aimed to evaluate the effect of caesarean delivery on IgA generation. METHODS Blood samples were obtained during 12 vaginal deliveries (VD) and 16 elective caesarean sections (ECS), and 2 and 6 months later. The number of immunoglobulin secreting cells (ICS)/ 106 cord and peripheral blood mononuclear cells were determined by the enzyme-linked immunospot method, the immunophenotypes by a flow cytometer and the cytokine concentrations in plasma/serum samples by ELISA. RESULTS The number of ISC/106 IgA-secreting cells expressed in median (interquartile ranges) in cord blood samples of VD vs. ECS were 19.5 (5.0-25.7) vs. 4.9 (0.0-8.4) respectively, p=0.03. The percentage of NK cells in ECS samples tended to be lower than that in VD; 12.2 (14.6-9.7) in ECS and 18.3 (25.1-11.3) in VD. The concentration of IL6 of ECS samples was lower than that of VD. These differences at birth were no longer significant when the infants were 2 and 6 months old. CONCLUSIONS These results indicate that ECS predisposes neonates to low capacity to generate IgA concomitantly with low circulating levels of IL6 and NK cells. Caesarean section delivery can hinder the first-line nonspecific immunity to enteral antigens of microbial or dietary origin at a critical period of life when the immune memory is yet to be established. This may explain the observation that the incidence of atopic diseases increases concurrently with the frequency of elective caesarean section deliveries in the developed countries.

Immunoglobulin-secreting Cells in the Surface Secretion on the Pharyngeal Tonsils

As B-lymphocytes on the pharyngeal tonsils constitute a considerable part of the leukocytes in the surface secretion, and their biological role is obscure, we explored their possible function with respect to immunoglobulin production. Twenty children scheduled for routine adenoidectomy participated. Surface secretion from 10 children was analysed for presence of plasma cells and cells from the secretions of the other 10 children were tested in enzyme-linked immunosorbent spot assays (ELISPOT-assays) for their capacity to secrete and produce IgA, IgM and IgG. Plasma cells and cells that secreted IgA, IgM and IgG respectively were present in the secretions of all tested children. In eight of ten children the IgG immunocytes, Ig-producing blasts and plasma cells, outnumbered the IgA immunocytes. The number of immunoglobulin secreting cells (ISCs) was reduced by half or more in cell suspensions exposed to the reversible protein synthesis inhibitor cycloheximide. It is concluded that immunocytes that produce and secrete immunoglobulin are present in the surface secretion on the pharyngeal tonsils. The production represents an addition to the immunoglobulins transported to the secretion by the poly-Ig receptor and by passive diffusion. The results shed new light on the pathogenesis of mucosal infections in the upper airways.

Intragastric administration of ursodeoxycholic acid suppresses immunoglobulin secretion by lymphocytes from liver, but not from peripheral blood, spleen or Peyer’s patches in mice

Ursodeoxycholic acid (UDCA) has been recognized as a therapeutic drug for primary biliary cirrhosis (PBC) and chronic viral hepatitis. As one of the mechanisms by which UDCA improves liver function tests in those patients, its immunomodulatory effect is currently considered important. Although the suppressive effects of UDCA on some cytokine productions, T-cell mediated cytotoxicity and immunoglobulin production were observed from in vitro studies, the immunomodulation in vivo by UDCA remains unclear. In the present study, we investigated the effect of UDCA administration on the number of immunoglobulin secreting cells in liver, peripheral blood, spleen and Peyer’s patches in mice using the enzyme linked immunospot assay and assessed whether the UDCA-mediated immunomodulation is liver-specific. It was demonstrated that intragastric administration of UDCA reduced immunoglobulin secretion by lymphocytes from liver, but not from peripheral blood, spleen, or Peyer’s patches. However, immunoglobulin production of those lymphocytes cultured in the presence of UDCA was suppressed, irrespective of their distribution sites, in a UDCA dose-dependent manner. When the concentrations of UDCA in portal and peripheral blood were measured using high performance liquid chromatography, UDCA was detectable in the portal blood in UDCA-treated mice, but not in peripheral blood, suggesting that the concentrations of UDCA in the environment surrounding lymphocytes may be an important factor for the modulation of lymphocyte functions.

Immunoreactivity of Roach,Rutilus rutilus,Following Laboratory Exposure to Bleached Pulp and Paper Mill Effluents

In order to study immunomodulation, controlled laboratory experiments were carried out with roach (Rutilus rutilus) exposed to bleached kraft mill effluent (BKME) or spent bleach liquor (SBL) from two pulp and paper mills using elementary chlorine and chlorine dioxide for bleaching. The total number of immunoglobulin-secreting cells (ISC) and the number of specific antibody-secreting cells (ASC) were determined by ELISPOT assay. Exposure to BKME resulted in decreased numbers of ISC in the spleen. To study the capability of response against foreign antigens the fish were immunized with bovine γ-globulin. Exposure to BKME or SBL reduced antigen-specific ASC response in fish. Moreover, the suppression of ASC response did not require exposure prior to immunization. Depuration of fish in clean water reveals that the immunosuppression caused by BKME is reversible. The ASC response in the BKME-pretreated fish returned to the same or even a higher level compared to untreated immunized fish and, in addition, the number of ISC increased greatly. The results of this study verify an earlier finding on poor antibody response due to exposure in a lake contaminated with BKME. Exposure to SBL alone suppresses antibody-mediated immunity, suggesting that compounds formed in bleaching are at least partly responsible for immunotoxic effects.

CD5+ B lymphocytes are the main source of antibodies reactive with non‐parasite antigens in Trypanosoma congolense‐infected cattle

Mice infected with African trypanosomes produce exceptionally large amounts of serum IgM, a major part of which binds to non-trypanosome antigens such as trinitrophenol and single-strand DNA. In this paper, we describe that in cattle infected with Trypanosoma congolense and T. vivax, similar antibodies are found, although they bind mainly to protein antigens, such as beta-galactosidase, ovalbumin and ferritin. The parasite non-specific IgM antibodies appear around the same time as the parasite-specific antibodies, but their origin and function are not clear. We tested the hypothesis that CD5+ B cells (or B-1 cells), which increase during trypanosome infections in cattle, are responsible for production of antibodies to non-trypanosome antigens. Splenic CD5+ and CD5- B cells from infected cattle were sorted and tested in a single cell blot assay. The numbers of immunoglobulin-secreting cells were similar in both B-cell populations. However, antibodies with reactivity for non-trypanosome antigens were significantly more prevalent in the CD5+ B-cell fraction and were exclusively IgM. The preference for production of these antibodies by CD5+ B cells and the expansion of this subpopulation during infections in cattle, strongly suggest that CD5+ B cells are the main source of trypanosome non-specific antibodies. We propose that these antibodies are natural, polyreactive antibodies that are predominantly secreted by CD5+ B cells. Since B-1 cells are up-regulated in many states of immune insufficiency, the immunosuppression associated with trypanosome infections may be responsible for the increase of this subset and the concomitant increase in trypanosome non-specific antibodies.

Immunoglobulin Production in Kawasaki Disease

The production of immunoglobulins that may include specific antibodies to an unknown agent was investigated in Kawasaki disease. That is, serum immunoglobulin concentrations and the numbers of immunoglobulin-secreting cells in peripheral blood mononuclear cells (PBMCs) without culture in vitro were enumerated in the course of the disease, to assess immunoglobulin production at a certain point in vivo. Results showed that the numbers of IgM-, IgG-, or IgA-secreting cells increased in the acute stage prior to increases in serum IgM, IgG, or IgA concentrations, respectively. Moreover, in 2 patients who had a relapse of the illness, the numbers of immunoglobulin-secreting cells were high at the relapse compared with those within 1 week after the initial onset. These results suggest that measurement of immunoglobulin-secreting cells in PBMCs is useful for assessment of the immunoglobulin production ability at a certain point in vivo. Thus, immunoglobulins abnormally produced may include specific antibodies to the epitopes of a certain agent.

Antibody synthesis in roach ( Rutilus rutilus); analysis of antibody secreting cells in lymphoid organs with ELISPOT-assay

The roach ( Rutilus rutilus L.) which is a cyprinid fish, was immunised with bovine γ-globulin (BGG) and the antibody synthesis was studied by counting the number of specific antibody secreting cells (SASC) in the spleen and anterior kidney, and by measuring the antibody concentration in the circulation. SASCs and the total number of immunoglobulin secreting cells (TISC) were counted with the ELISPOT (enzyme-linked immunospot) assay, and anti-BGG antibodies and the concentration of immunoglobulin in sera were assayed by ELISA (enzyme-linked immunosorbent assay). The present modification of the ELISPOT-assay takes advantage of biotin-avidin amplification and yields easily detectable and nonfading spots that may be counted even after several weeks of storage. It is also possible to count the number of SASC and TISC in different organs. In this study, immunisation of the roach with protein antigen via the intraperitoneal route resulted in a similar response in the spleen and in the kidney. There was no preferential organ distribution of the number of SASC or TISC and no difference in the timing of the response in the organs. The humoral response due to immunisation in the serum correlated with cellular responses in the organs.

Expression of secreted immunoglobulin heavy chain genes and immunoglobulin-secreting cells in human lymphocytes.

The numbers of immunoglobulin-secreting cells in peripheral blood mononuclear cells and the expression of mRNA for secreted type of immunoglobulin heavy chains were investigated in healthy children, compared with the percentages of surface immunoglobulin-bearing cells and the expression of mRNA for membrane-bound type of immunoglobulin heavy chains, respectively. Although a difference between expression of mu s mRNA and mu m mRNA was unclear, mu mRNA was well transcribed. The expression of gamma s mRNA or alpha s mRNA was markedly higher than that of gamma m mRNA or alpha m mRNA. However, although the detection methods could be of different sensitivities, the percentage of IgM-, IgG-, or IgA-secreting cells was markedly low, compared with the percentage of surface IgM-, IgG-, or IgA-bearing cells, respectively. Therefore, additional regulation of the pattern of the immunoglobulin gene expression may be exerted at the translational and post-translational stages.

Immune defense to dietary cow milk in healthy infants.

The healthy young infant is immunologically adapted to receiving vast amounts of antigens in diet. At the age of 6 months, nine infants were put on a CM elimination diet for 3 weeks and then challenged with CM. Gut immune response was evaluated indirectly with ELISPOT assay at 6 months, after CM elimination (Day 1) and challenge (Day 8), and at 11 months. CM elimination decreased the numbers of immunoglobulin secreting cells (ISC): in the IgM class from mean [95% CI] 4969 [2555, 9653] at 6 months to 1716 [1024, 2873]/10(6) cells on Day 1 (t = 3.14, p = 0.01); and in the IgG class from 5547 [3562, 8630] to 2684 [1383, 5208]/10(6) cells (t = 3.29, p = 0.01). CM challenge further reduced inter-individual variation, and at 11 months the scatter of ISC was comparable to that at 6 months. Specific antibody-secreting cells of the IgA and IgG class were seen at 6 months and again at 11 months, while specific IgM-secreting cells persisted throughout the dietary manipulation. The results indicate that diet profoundly affects the immune defense system, and further suggest that a focused immune response is vital in acquisition of tolerance to dietary antigens.

Correlations Between Serum Immunoglobulin Concentrations and Immunoglobulin Secreting Cells in Healthy Peripheral Blood

In this study, to assess the ability of immunoglobulin productions at a certain point in vivo, the numbers of immunoglobulin secreting cells in noncultured peripheral blood mononuclear cells (PBMCs), B-cell populations, or T-cell populations were enumerated. As a result, the numbers of immunoglobulin-secreting cells in B-cell populations were three to five times of those in PBMCs, suggesting that in this assay T cells are not necessary in vitro for the immunoglobulin secretion from secreting cells since B cells may have received factors (lymphokines) from T cells in vivo. Moreover, in healthy individuals, the numbers of immunoglobulin-secreting cells in PBMCs were well correlated to serum immunoglobulin concentrations in all three classes. The results suggest that measurement of immunoglobulin secreting cells in PBMCs are useful for assessment of the ability of immunoglobulin productions at a certain point in vivo.

Cow's milk provocation induces an immune response to unrelated dietary antigens.

The activation of immune mechanisms was evaluated by the solid phase enzyme linked immunoassay of immunoglobulin and specific antibody secreting cells in 27 patients (aged from nine to 69 months), subjected to a diagnostic cow's milk challenge or a rechallenge. A significant rise in the total number of immunoglobulin secreting cells was associated with clinically positive (n = 17), but not a negative (n = 10) cow's milk challenge in all immunoglobulin isotypes. The number of specific antibody secreting cells against beta lactoglobulin, mean (95% confidence interval), increased from 4.8 (1.4, 15.8) to 16.9 (5.5, 52.7) specific antibody secreting cells/10(6) cells, p = 0.02, and against casein from 2.2 (0.8, 6.1) to 7.5 (2.5, 22.5) specific antibody secreting cells/10(6) cells, p = 0.01, in patients positive to challenge in the IgM class only, indicating defective immune elimination of milk antigens. In addition to the specific immune response to cow's milk antigens, an increase in IgM specific antibody secreting cells against an unrelated dietary antigen, gliadin, from 8.2 (2.1, 31.1) to 31.0 (14.2, 67.6) specific antibody secreting cells/10(6) cells, p = 0.01, was observed. These results indicate that cow's milk challenge, in patients who have cow's milk allergy, induces a strong non-antigen specific immune response that includes a response against unrelated antigens concomitantly present in the intestinal lumen. Activation of such immune mechanisms may hence reflect increased antigenic load caused by the immune mediated lesion in the gut mucosa.