Mean IgG Levels Research Articles

Serum and Middle Ear Immunoglobulins in Suppurative Otitis Media

Background and Purpose: Despite the increasing occurrence of suppurative otitis media (SOM), the content of immunoglobulin fractions in the middle ear secretion (MES) has still not been determined. Method: The serum and MESwere analyzed for IgG and M using enzyme-linked immunoassay. Result: The subjects and controls were 30 males and 22 females, between 6 months and 9 years old, with a mean age of 6 years (SD = 3.26). The patient group included 20 chronic SOM (CSOM) and 17 acute SOM (ASOM) cases, and sera of 15 subjects made the control group. The mean serum IgG levels were for controls 1,051 mg/dl, ASOM 666.1 mg/dl and CSOM 1,321.1 mg/dl; the MES levels were for ASOM 203.4 mg/dl and CSOM 511.5 mg/dl. The mean serum IgM levels were for controls 35 mg/dl, ASOM 64.1 mg/dl and CSOM 40 mg/dl; the MES levels were for ASOM 22.59 mg/dl and CSOM 3.44 mg/dl. The mean MES:serum ratios for IgG and IgM were between 0.1 and 0.4 in ASOM and CSOM. The ratio of serum IgG levels of controls to ASOM cases was 0.66 while that of controls to CSOM was 1.3. The corresponding ratios of IgM were 1.6 and 0.88. Multivariate analysis revealed a significant correlation between serum IgG levels of ASOM and CSOM (p = 0.043) and MES IgG (p = 0.02) in ASOM and CSOM but no correlation between serum IgG levels in controls and ASOM (p = 0.25), serum IgM levels in controls and CSOM (p = 0.62) and serum IgM levels in controls and ASOM (p = 0.73), ASOM and CSOM (p = 0.064) and MES IgM levels of ASOM and CSOM (p = 0.06). Conclusions: Monitoring of the serum and MES IgG in ASOM may provide a useful index to assess the possibility of progression to chronicity. This forms a database for the immunological status of SOM patients.

IgG subclass levels and immune reconstitution after T cell-depleted allogeneic bone marrow transplantation

Defects of humoral immunity are well documented after bone marrow transplantation (BMT). Immunoglobulin recovery can be impaired and selective deficiencies of IgG subclasses have been reported. The nature of these deficiencies may reflect patterns of infection in the post-BMT period. We studied immunoglobulin and IgG subclass recovery in 20 long term (greater than 100 days) survivors of T depleted allogeneic BMT. Although there was no fall in mean levels of IgG, IgM or IgA for the patient group, 14 patients (70%) developed a deficiency of one or more immunoglobulin isotype at some stage post-BMT. Eight patients (40%) had deficiency of IgG, IgA and IgM and six had selective deficiencies. When IgG subclasses were measured it was seen that mean levels of IgG2 and IgG4 fell post-BMT with trough levels occurring at around 120 days post-transplant. Sixty per cent of patients developed IgG2 subclass deficiency and of these patients 78% had an associated IgG4 deficiency. Deficiencies of IgG1 and IgG3 were less common and less prolonged than those of IgG2 and IgG4; in addition, mean levels of IgG1 and IgG3 showed a rise early post-BMT. In conclusion, a majority of our patients developed immunoparesis following BMT, usually at around 120 days after transplantation. IgG2 subclass deficiency, often in association with IgG4 deficiency, is common and may occur despite normal total IgG levels. Deficiencies of immunoglobulin and IgG subclasses may persist for longer than 1 year post-BMT. Differing profiles of immunoglobulin and IgG subclass recovery may help dictate patterns of infection in long-term survivors of BMT.

Diagnosis of pulmonary tuberculosis using MTB12 and 38‐kDa antigens

Mycobacterium tuberculosis MTB12 protein plays an essential role in pro-inflammatory responses during the early stages of human pulmonary tuberculosis (TB), even though the T-cell immunoreactivity of MTB12 is weaker than that of the 30-kDa antigen (Ag). The objective of this study was to evaluate the humoral immune responses induced by MTB12 Ag during human TB. Using an ELISA, anti-MTB12 IgG levels in the sera of TB patients and healthy controls were compared with those induced by the 30-kDa Ag and 38-kDa Ag, or both. In TB patients, the sensitivity and specificity of MTB12 Ag were similar to those of other antigens at 53.0% and 95.4%, respectively. However, the sensitivity increased to 73.0% when the combination of MTB12 and 38-kDa Ag was measured. Specificity remained high when a combination of the individual antigens was used. ELISA results showed that after anti-tuberculosis treatment, the mean IgG levels against MTB12 alone or MTB12 plus 38-kDa Ag were significantly increased in the TB patients, while those against MTB12 plus 30-kDa Ag were not (P < 0.05). Collectively, these data suggest that MTB12, in combination with 38-kDa Ag, can be used to increase the accuracy of pulmonary TB diagnosis.

Postoperative change of anti-Thomsen-Friedenreich and Tn IgG level: The follow-up study of gastrointestinal cancer patients

To study the influence of tumor removal on the serum level of IgG antibodies to tumor-associated Thomsen-Friedenreich (TF), Tn carbohydrate epitopes and xenogeneic alphaGal, and to elucidate on the change of the level during the follow-up as well as its association with the stage and morphology of the tumor and the values of blood parameters in gastrointestinal cancer. Sixty patients with gastric cancer and 34 patients with colorectal cancer in stages I-IV without distant metastases were subjected to follow-up. The level of antibodies in serum was determined by the enzyme-linked immunosorbent assay (ELISA) using synthetic polyacrylamide (PAA) glycoconjugates. Biochemical and haematological analyses were performed using automated equipment. In gastrointestinal cancer, the TF antibody level was found to have elevated significantly after the removal of G3 tumors as compared with the preoperative level (u = 278.5, P < 0.05). After surgery, the TF and Tn antibody level was elevated in the majority of gastric cancer patients (sign test, 20 vs 8, P < 0.05, and 21 vs 8, P < 0.05, respectively). In gastrointestinal cancer, the elevated postoperative level of TF, Tn and alphaGal antibodies was noted in most patients with G3 tumors (sign test, 22 vs 5, P < 0.01; 19 vs 6, P < 0.05; 24 vs 8, P < 0.01, respectively), but the elevation was not significant in patients with G1 + G2 resected tumors. The postoperative follow-up showed that the percentage of patients with G3 resected tumors of the digestive tract, who had a mean level of anti-TF IgG above the cut-off value (1.53), was significantly higher than that of patients with G1 + G2 resected tumors (c2 = 3.89, all patients; c2 = 5.34, patients without regional lymph node metastases; P < 0.05). The percentage of patients with a tumor in stage I, whose mean anti-TF IgG level remained above the cut-off value (1.26), was significantly higher than that of patients with the cancer in stages III-IV (c2 = 4.71, gastric cancer; c2 = 4.11, gastrointestinal cancer; P < 0.05). The correlation was observed to exist between the level of anti-TF IgG and the count of lymphocytes (r = 0.517, P < 0.01), as well as between the level of anti-Tn IgG and that of serum CA 19-9 (r = 0.481, P < 0.05). No positive delayed-type hypersensitivity reaction in skin test challenges with TF-PAA in any of the fifteen patients, including those with a high level of anti-TF IgG, was observed. The surgical operation raises the level of anti-carbohydrate IgG in most patients, especially in those with the G3 tumor of the gastrointestinal tract. The follow-up demonstrates that after surgery the low preoperative level of TF antibodies may be considerably increased in patients with the carcinoma in its early stage but remains low in its terminal stages. The stage- and morphology-dependent immunosuppression affects the TF-antibody response and may be one of the reasons for unresponsiveness to the immunization with TF-antigens.

Ocena odpowiedzi humoralnej przeciwko antygenom prątka w popłuczynach oskrzelowo-pęcherzykowych u chorych na gruźlicę płuc potwierdzoną bakteriologicznie i metodami genetycznymi

The resistance to TB is cells-mediated but humoral response is common and may be correlated with the lack of effective local cellular defence mechanisms. The goal of the study was to evaluate IgG, IgA and IgM mediated humoral immune response against 38kDa plus 16kDa and 38kDa plus lipoarabinomannan (LAM) mycobacterial antigens in BALF from patients with culture confirmed and PCR positive pulmonary tuberculosis (TB) compared to non-tuberculous controls (NTB). 79 BALF samples (46 TB and 30 NTB) were examined. In 25 BALF samples from TB patients nucleic acids from M. tuberculosis were detected by PCR method. Commercially available ELISA - based assays against proteins 38kDa and 16kDa or 38kDa plus LAM were used. Three different dilutions of BALF: 1 : 1 and 1 : 10 were tested. Mean IgG level against 38 + LAM was significantly higher in TB group compared to control (p < 0,0001). No difference was observed between TB and NTB group in titer of IgM antibodies. Sensitivity of the tests based on IgG anti38kDa + 16kDa was 49%, IgG anti38kDa + LAM - 33%, IgA anti38kDa + LAM - 100%, IgM anti38kDa + LAM - 35%. Specificity of examined assays: IgA anti38kDa + LAM - 13%, IgM anti38kDa + LAM - 75%, IgG anti38kDa + 16kDa - 87%, IgG anti38kDa + LAM - 93%. The findings of the study indicate that TB is associated with the presence of detectable levels of antibodies in the BALF. Examined tests detecting IgG in BALF can be used in combination with other diagnostic methods to increase diagnostic accuracy of pulmonary TB.

C1 inhibitor, C3 activator, IgG, IgA, and IgM titers in Nigerian sickle cell disease patients with plasmodium falciparum.

Sickle cell disease (HbSS) is a major health problem in Nigeria and malaria has been implicated as a leading cause of morbidity/mortality in sickle cell disease patients. Few reasons were put forward to explain the observed morbidity/mortality of HbSS subjects due to Plasmodium falciparum (P. falciparum) malaria. To determine the level of immunoglobulin classes (IgM, IgA, and IgG) and regulators of complement system (C1 inhibitor and C3 activator) in Nigerian HbSS patients with and without P. falciparum parasitemia. A total of 64 subjects were considered, including 10 HbSS genotypic subjects with P. falciparum parasitemia (HbSS+PfM), 18 HbAA genotypic subjects with P. falciparum parasitemia (HbAA+PfM), 20 HbSS without P. falciparum parasitemia (HbSS-PfM), and 16 HbAA genotypic subjects without P. falciparum parasitemia (HbAA-PfM). IgM, IgA, IgG, C1 inhibitor, and C3 activator titers were quantified by single radial immunodiffusion method. The mean levels of IgG in HbSS+PfM (2373.90+/-1772.81mg/dl) and HbAA+PfM (1868.80+/-0.00mg/dl) were significantly higher compared with HbSS-PfM (644.55+/-171.15mg/dl) or HbAA-PfM (659.75+/-158.01mg/dl) patients. HbAA-PfM subjects had the lowest level of IgM (67.27+/-63.7mg/dl), though no significant difference was observed comparing mean levels of IgM between the four groups. IgA titer was significantly higher in HbSS-PfM patients (249.00+/-94.8mg/dl) compared with HbAA-PfM (p<0.05), HbAA+PfM (p<0.05), or HbSS+PfM (p<0.05). The mean values of C1 inhibitor were lower in HbSS+PfM and HbAA+PfM compared with HbSS-PfM or HbAA-PfM. However, HbAA+PfM had a significantly lower value of C1 inhibitor compared with HbAA-PfM (p<0.01). C3 activator was highest in HbSS-PfM (17.10+/-7.35mg/dl) and was significantly higher compared with HbSS+PfM (p<0.05). Increased C1 inhibitor and decreased C3 activator in HbSS+PfM compared with HbAA+PfM shows that deranged regulation of complement factors may be responsible for increased susceptibility of HbSS to P. falciparum malaria.

ANTIBODIES TO PLASMODIUM VIVAX APICAL MEMBRANE ANTIGEN 1: PERSISTENCE AND CORRELATION WITH MALARIA TRANSMISSION INTENSITY

The antibody responses to the apical membrane antigen 1 of the Plasmodium vivax (PvAMA-1) were investigated in subjects living in areas of Brazil with different levels of malaria transmission. The prevalence and the levels of IgG to PvAMA-1 increased with the time of exposure. The frequency of a positive response and the mean IgG level were higher in areas where malaria prevalence was more intense, especially among non-infected subjects exposed to moderate transmission over a period of 20 years. The proportions and levels of IgG1and IgG3 isotypes were significantly higher among those subjects with long-term exposure. Antibodies, mainly IgG1, to PvAMA-1 persisted for seven years among subjects briefly exposed to malaria in an outbreak outside the Brazilian malaria-endemic area. These data show the highly immunogenic properties of PvAMA-1 and emphasize its possible use as a malaria vaccine candidate.

The influence of tobacco smoking on humoral immune response in insulin dependent diabetic pregnancy

Tobacco smoking products have a heavy impact on the public health of developed as well as non-developed countries by being a main etiologic factor for the induction of cardiovascular diseases and tobacco-related cancer. The purpose of this study was to determine the influence of tobacco smoking on the measurement of the humoral immune response in Egyptian pregnant women with type 1 diabetes. Concentrations of serum immunoglobulin A, G and M in 35 smoking, 35 non-smoking pregnant women with type 1 diabetes and 35 matched normal women were measured by ELISA. Women were matched by age and working life with controls. Measurements suggested that diabetic smokers had decreased levels of IgG and IgM in their sera. It was found that normal individuals had mean IgA, IgG and IgM levels of 2.80 mg/ml, 9.33 mg/ml and 1.66 mg/ml, respectively while non-smoker women suffering from type 1 diabetes had mean levels of 3.47 mg/ml, 10.97 mg/ml and 2.05 mg/ml (p<0.0004,p<0.0001 andp<0.0002). However, the mean level of IgA, IgG and IgM in diabetic smoker sera was determined to be 3.33 mg/ml, 8.07 mg/ml and 1.31 mg/ml, respectively (p<0.003,p<0.0001 andp<0.0001). The obtained results suggest that toxic smoke components were immuno-suppressant and may well play a part in the complex immuno-pathogenesis interaction. The increased risk of smoking in insulin dependent diabetic pregnant women during pregnancy is a further reason to encourage pregnant women to quit tobacco smoking.

Serum immunoglobulins in psoriasis before and after ultra violet light therapy.

SUMMARY.— A significant increase of the mean IgA globulin value was noted in 105 patients with ordinary psoriasis whereas the mean IgG and IgM globulin levels remained normal. Thirty-two of these patients received u.v. light therapy which resulted in resolution of the skin lesions. At this stage the IgA levels fell to the normal range. The possibility of the skin eruption influencing the IgA serum levels is discussed.

Humoral Immune Response against Mycobacterial Antigens in Patients with Tuberculosis and Mycobacterial Infections Other than Tuberculosis

The aim of the study was to compare humoral immune response against various mycobacterial antigens in TB and MOTT vs healthy control group. 350 serum samples from TB patients, 20 samples from MOTT patients and 58 samples from healthy donors were examined. ELISA detecting IgG, IgA and IgM against antigens: 38 kDa and 16 kDa, 38kDa and lipoarabinomannan, and A-60 were used. Mean IgG level was higher in TB compared to healthy controls (p<0,001). Mean IgG level against 38kDa and 38 + 16 kDa mycobacterial antigens was higher in TB than in MOTT group. Mean level of the IgG, IgA and IgM antibodies against LAM was higher in MOTT compared to TB patients. In all subgroups person-to-person heterogeneity of antigen recognition was observed. Humoral immune response to recombinant mycobacterial antigens significantly differs in TB and MOTT patients.

The Effects of Probiotic and Mannanoligosaccharide on some Haematological and Immunological Parameters in Turkeys

The study was conducted to investigate the effects of mannanoligosaccharide (MOS) and probiotic supplementation on haematological and immunological parameters in turkeys. A total of 72, 15-day-old white hybrid converter turkey poults were used in this study. Poults were assigned into three groups, each group consisted of six poults and the trial was repeated four times. The control group was fed a basal diet without supplemented probiotic and MOS, and treatment groups were fed either 1 g/kg MOS or probiotic added diets. At the end of the 15-week treatment period, samples of blood were collected to determine immunological and haematological values. The comparison among the groups showed that both the probiotic and MOS supplementation resulted in significant increases (P < 0.05) in the serum IgG and IgM levels, and significant decreases (P < 0.05) in the peripheral blood T lymphocyte percentage compared with those of the control group. Mean serum IgG level (7.06 g/l) was significantly higher (P < 0.05) in poults supplemented with probiotic compared with MOS (6.76 g/l). It was observed that the probiotic supplementation caused statistically significant increases (P < 0.05) in the erythrocyte count, haemoglobin concentration and haematocrit values, but MOS supplementation did not have a significant effect (P > 0.05) on these parameters. Total leucocyte and differential leucocyte counts were not affected by dietary MOS and probiotic supplementation. These results show that MOS or probiotic may elevate IgG and IgM levels in turkey. The MOS and probiotic that enhance immunoglobulin levels will have a more positive effect on growth performance, production and turkeys' ability to resist disease.

Effect of anti-immunoglobulin antibodies provides new insights into immune response to HCV

To determine the effect of anti-immunoglobulin antibodies on the measurement of the humoral immune response in hepatitis C virus (HCV) infected patients. Anti-immunoglobulin antibodies were defined using sheep immunoglobulins as a target to characterize distinct changes in patterns of immunoglobulin levels. Serum immunoglobulin A, G and M concentrations were measured by ELISA in 45 patients with recent-onset HCV infection and 45 matched normal individuals. It was found that normal individuals had mean IgA, IgG and IgM levels of 2.67 mg/ml, 9.39 mg/ml and 1.77 mg/ml, respectively while HCV infected patients had mean levels of 3.19 mg/ml, 10.76 mg/ml and 1.94 mg/ml. These represented significant increases in immunoglobulin levels in the sera of HCV patients compared to normal individuals (p < 0.0001, p < 0.00004 and p < 0.0004). Anti-immunoglobulin antibodies lead to an overestimation of serum immunoglobulin levels in HCV patients. Interestingly, the mean levels of immunoglobulins A, G and M in HCV infected sera, determined after purification from anti-sheep immunoglobulins, was 2.73 mg/ml, 9.55 mg/ml and 1.79 mg/ml. Therefore, there was no significant difference in HCV patients compared to normal individuals (p < 0.42, p < 0.36 and p < 0.44). The presence of circulating immune complex in serum during the early phase of infection may contribute to immunopathological effects in the infected host and provide some new insights into antibody response to HCV.

P0898 LOW SERUM IGG LEVELS IN CHILDREN DURING THE ACUTE PHASE OF SEVERE BACTERIAL INFECTION

Introduction: In adults low serum albumin during bacterial infection correlates with poor outcome (1). In the literature there is no mention of IgG levels. Aim: To study IgG and albumin levels in children during the first 72 h of acute severe bacterial infections. Methods: Patient and Methods: Over 24 months, children 1–14 y hospitalized with fever due to acute bacterial infections: lobar pneumonia, pyelonephritis or lymphadenitis were evaluated in the first 96 h of hospitalization for serum albumin and IgG levels. Results: 50 children were studied: 21 children group I, were found to have albumin of 35 G/L). 29 children group II, had albumin > 36 G/L (range 36–45). The mean IgG levels in group I was IgG=8.49 (range 4.5–11.2 G/L). The mean IgG level of group II was IgG=11.3 (range 5.9–18.4 G/L) Discussion: The direct correlation between low albumin and low IgG levels during the first days of a bacterial infection (2) can be explained by a common pathophysiologic process acting to lower both levels. IgG levels usually rise, the lower IgG levels could be explained by a losing process during bacterial infections. Conclusion: Based on our observation that protein losing enteropathy is a frequent finding in acute severe bacterial infection (2) we suggest that protein losing is the pathologic mechanism leading to lower albumin and IgG levels during the first days of acute bacterial infection.

Vaccination against hepatitis A and B in patients coinfected with HIV and hepatitis C

+ 1.2) versus H. Pylori negative ( 1.95+ 1.48). There was no statistically significant difference in mean IgG levels, PPD response, age, sex, or ferritin level in the two groups. Response to antiviral therapy was also not im2acted by the H. Pykiri status. Our preliminary findings suggest a decreased degree of fibrosis in HCV patients co-infected with H. Pylori and show no association with co-infection and response to antiviral therapy. A larger sample size and further studies involving other inflammatory and immune markers may reveal the role H. Pylori infection has in chronic HCV infection and its treatment.

Effects of Testosterone Undecanoate as a Male Contraceptive Candidate on Rat Immunological Features

Testosterone undecanoate (TU) is under phase III clinical trial as a hormonal male contraceptive in China. Sex hormones can modulate the immune system. Female hormonal contraceptives may affect SIV/HIV‐1 transmission. To evaluate the safety of TU and to understand whether long‐term use of TU for a male contraceptive affects users' immunological features, adult male rats were treated for a 32‐week TU‐treated phase at the dose of 20 mg TU/kg body weight and a 24‐week recovery phase. The reproductive and immunological parameters of 4–6 rats in each subgroup were examined at the stated time point. The mean sperm count and viability in the treated rats were significantly suppressed (p < 0.01). In the TU‐treated group: the mean blood leukocyte and lymphocyte counts; the proliferation indexes of T cells from peripheral blood mononuclear cells (PBMC) and spleen; and, of B cells from spleen, as well as the mean counts of blood T, NK, and B cells decreased in comparison with those of control group. These decreases were not significant (p > 0.01). Similarly, the mean serum IgM, IgG, and IgA levels and complement activity in TU‐treated rats were lower than those in control group (p > 0.01), and the changes in the antibody levels of the examined genital secretions were not significant (p > 0.01). The changes in the thickness of urethra epithelium, and in secretory component (SC) expression in genitals were not observed in the treated group. These results demonstrated that long‐term supraphysiological TU injection did not obviously affect the examined rat immunological parameters.

Differences in the serum immunoglobulin concentrations between dairy and beef calves from birth to 14 days of age

The changes in serum levels of immunoglobulins G, M and A of dairy and beef calves of well-managed herds were monitored from birth to 14 days post partum using single radial immunodiffusion. Serum levels of all three immunoglobulin classes reached its peak at 24 hours in both groups of calves after birth, at which time there were very high levels of each immunoglobulin present. The mean IgM and IgA levels of the two groups became same at 6 days and 8 days of age, respectively but the mean IgG level of beef calves was approximately twice that of dairy calves throughout the experiment.

Increased serum immunoglobulin levels are common in mycosis fungoides and Sézary syndrome

Background: Patients with cutaneous T-cell lymphoma (CTCL; mycosis fungoides [MF] and Sézary syndrome [SS]) acquire immunodeficiency and opportunistic infections. Objective: We attempted to determine whether abnormalities of humoral immunoglobulin levels are present. Methods: A retrospective analysis of serum immunoglobulin levels in patients with CTCL at baseline evaluation at a cancer center was compared to levels in patients with leukemias and levels in healthy control subjects. Results: A total of 254 of 650 patients with CTCL evaluated between 1987 and 2001 had baseline quantitative immunoglobulin levels. Mean IgG, IgA, and IgM levels were similar among all MF/SS patients versus controls. The percentages of MF/SS patients with elevated levels of each immunoglobulin class were higher than percentages in healthy controls, and elevated IgA levels occurred among late versus early patients (P = .043). Conclusion: High immunoglobulin levels are more frequent in patients with MF and SS than in healthy controls, patients with chronic lymphocytic leukemia, and patients with hairy cell leukemia. High IgA levels are more frequent in late stage MF/SS. (J Am Acad Dermatol 2002;47:685-91.)

Serum IgE levels in Korean patients with human immunodeficiency virus infection.

BackgroundHuman immunodeficiency virus (HIV) infection results in a selective CD4+ T cell depletion and an impairment of T cell regulation. Despite the immune depletion, the progression of HIV infection is accompanied by the stimulation of antibody synthesis. Thus, the prevalence and amplitude of the increase of total serum IgE level and the relationship between the IgE levels and the degree of immunodeficiency were evaluated in patients with HIV infection.MethodTwenty-six Korean adults infected with HIV, in different stages, were evaluated for serum IgE level and CD4+ T cell count. Serum IgG, IgM and IgA levels were also determined. All subjects enrolled in this study denied an individual and familial history of atopic diseases. The possibility of parasitic infestation was also excluded by history and stool examination.ResultsThe mean serum IgE level was 473.5 IU/L with a standard deviation of 671.4 IU/L (range: 15.9–2000 IU/L) and increased serum IgE levels (>200 IU/L) were found in 38.5% of the study population. The mean serum IgG, IgA and IgM levels were 1,939.5±588.6 mg/dL (normal: 751–1,560 mg/dL), 388.9±216.7 mg/dL (normal: 82–453 mg/dL) and 153.6±75.3 mg/dL (normal: 46–304 mg/dL), respectively. The CD4+ T cell count was inversely correlated to the serum IgE level (r=−0.429, p<0.05), but not to the other isotypes of immunoglobulin.ConclusionSerum IgE levels are increased in adults with HIV infection and could be useful as a marker of disease progression. Further study is needed to elucidate the causes and clinical significance of these findings.

Association of the IgG response to Plasmodium falciparum merozoite protein (C-terminal 19 kD) with clinical immunity to malaria in the Brazilian Amazon region.

The antibody response to the C-terminal 19-kD fragment of Plasmodium falciparum merozoite surface protein-1 (PfMSP1-19) was investigated in groups of subjects living in areas of Brazil with different levels of malaria transmission. The prevalence and the levels of IgG to PfMSP1-19 increased with the time of exposure and were positively correlated with the absence of clinical symptoms in parasitemic patients. The frequency of positive response and the mean level of IgG were higher in areas where malaria prevalence was more intense, especially among asymptomatic patients. The serum absorbance values of the IgG1 isotype were significantly higher among subjects with long-term exposure and in asymptomatic infections. These data suggest a protective role of IgG1 in naturally acquired immunity in spite of the unstable transmission levels in the Brazilian Amazon.

Anti-Gal alpha 1-3Gal IgM and IgG antibody levels in sera of humans and old world non-human primates.

Organs transplanted from pig to primate are rejected within minutes or hours by an antibody-dependent, complement-mediated mechanism [hyperacute rejection (HAR)]. Even after depletion of anti-Gal alpha 1-3Gal (Gal) antibody (Ab), for example by extracorporeal immunoadsorption, return of natural Ab is believed to be a major factor in the initiation of acute humoral xenograft rejection. Various non-human primates are used as recipients of pig organs in experimental discordant xenotransplantation (XTx) models. However, anti-Gal IgM and IgG levels in non-human primates may differ from those in humans. Serum levels of anti-Gal IgM and IgG were measured by enzyme-linked immunosorbent assay (ELISA) in humans (n=14), chimpanzees (n=8), baboons (n=214), cynomolgus monkeys (n=29), rhesus monkeys (n=23) and Japanese monkeys (n=6). The mean level of anti-Gal IgM was significantly higher in chimpanzees than in other groups, while in rhesus monkeys it was significantly lower than in other groups, except baboons and Japanese monkeys. The mean human anti-Gal IgG level was higher than in other groups and this difference reached statistical significance except with regard to chimpanzees. The mean anti-Gal IgG level in baboons was significantly lower than that in humans, chimpanzees and cynomolgus monkeys. The measured differences in anti-Gal IgM and IgG levels may affect the kinetics of Ab removal and rate of return in different species, and thus may have relevance for translating work in non-human primate models to the clinical setting.