IgG antibodies, chronic bronchitis, and pulmonary function values in farmer's lung patients and matched controls

We measured IgG antibody levels against eight different microbes in farmer's lung (FL) patients an average of 14 years after the first diagnosed episode of FL and in matched controls. The study population consisted of 87 FL patients and 81 control farmers, matched by age, sex, and smoking habits. Clinical studies included the measurement of IgG antibody levels against Absidia corymbifera, Aspergillus umbrosus, A. fumigatus, Humicola grisea, Saccharopolyspora rectivirgula, Penicillium brevicompactum, Rhodotorula glutinis, and Thermoactinomyces vulgaris, in addition to spirometry, pulmonary diffusing capacity (DL(CO)), and the evaluation of chronic bronchitis. Median IgG antibody levels were two or more times higher in FL patients than control farmers against Ab. corymbifera, S. rectivirgula, and T. vulgaris (P<0.001). Against A. fumigatus, H. grisea, and R. glutinis, FL patients also had significantly higher antibody levels. FL patients often had positive antibody titers against several microbes, whereas control farmers usually had a positive titer against one or two microbes. A positive association between IgG antibody levels and chronic bronchitis and DL(CO) was observed in FL patients, but not in control farmers. It is suggested that the high antibody levels noted in FL patients were due not only to high exposure but also to individual sensitivity to environmental microbes.     

Stability of Natural Self-Reactive Antibody Repertoires During Aging

We have used a quantitative immunoblotting technique to analyze the repertoires of self-reactive antibodies in serum samples obtained from the same five healthy adults over a 25-year interval. The average age of the donors was 43 years at the time of the first serum sample and 69 years at the time of the second serum sample. The antibody repertoires of IgM and IgG were found to be strikingly similar among individuals in both early and late samples. Densitometric profiles of self-reactivity of serum IgM and of purified serum IgG remained unchanged over the 25-year interval. The total reactivity of serum IgG decreased significantly over the 25-year period. The observed stability of the natural self-reactive IgM and IgG antibody repertoires with aging supports the view that autoreactive B cells in the normal immune system are positively selected for reactivity with a limited set of immuno-dominant self-antigens throughout life.     

Leucoéncephalopathie multifocale progressive

Summary A young woman presented a mixed congenital and familial immunodeficiency syndrome consisting in an absence of IgA and lowered levels of IgG and IgM, with a defect in cellular immunity. She had a mild malabsorption syndrome with slight alterations of the jejunal mucosa. Non-caseating tuberculoid granulomata were found in skin lesions, in lymph nodes and in the spleen. At age 27 the patient died of a neurological disease of 4 months duration. Autopsy revealed a very widespread demyelinating process involving mainly the right cerebellar hemisphere but also most of the pons and left cerebellum, with the typical morphologic characters of PML. In the hemispheres lesions were limited to microscopical microglial nodules with discrete demyelination. A review of 86 published cases of PML revealed 9 other cases in which lesions showed a strong predilection for the subtentorial territories. This sampling allows for the assumption that some 11% of the cases of PML have this particular lesion distribution. Other pertinent features of this case are briefly discussed.

     

Combined lesions of cholinergic and serotonergic neurons in the rat brain using 192 IgG-saporin and 5,7-dihydroxytryptamine: neurochemical and behavioural characterization

This study assessed behavioural and neurochemical effects of i.c.v. injections of both the cholinergic toxin 192 IgG-saporin (2 microgram) and the serotonergic toxin 5,7-dihydroxytryptamine (5,7-DHT; 150 microgram) in Long-Evans female rats. Dependent behavioural variables were locomotor activity, forced T-maze alternation, beam walking, Morris water-maze (working and reference memory) and radial-maze performances. After killing by microwave irradiation, the concentrations of acetylcholine, monoamines and 5-hydroxyindoleacetic acid (5-HIAA) were measured in the hippocampus, frontoparietal cortex and striatum. 192 IgG-saporin reduced the concentration of acetylcholine by approximately 40% in the frontoparietal cortex and hippocampus, but had no effect in the striatum. 5,7-DHT lesions reduced the concentration of serotonin by 60% in the frontoparietal cortex and 80% in the hippocampus and striatum. Noradrenaline was unchanged in all structures except the ventral hippocampus where it was slightly increased in rats given 192 IgG-saporin. Cholinergic lesions induced severe motor deficits but had no other effect. Serotonergic lesions produced diurnal and nocturnal hyperactivity but had no other effect. Rats with combined lesions were more active than those with only serotonergic lesions, showed motor dysfunctions similar to those found in rats with cholinergic lesions alone, and exhibited impaired performances in the T-maze alternation test, the water-maze working memory test and the radial-maze. Taken together and although cholinergic lesions were not maximal, these data show that 192 IgG-saporin and 5,7-DHT lesions can be combined to selectively damage cholinergic and serotonergic neurons, and confirm that cholinergic-serotonergic interactions play an important role in some aspects of memory, particularly in spatial working memory.     

抗体夹心酶联免疫吸附法测定重组E.coli L-门冬酰胺酶研究

用重组E.coliL-门冬酰胺酶免疫家兔，DEAE-纤维素柱层析纯化IgG，采用二步戊二醛交联法将辣根过氧化物酶标记抗体，建立抗体夹心酶联免疫吸附法，测定大鼠血浆中重组E.coliL-门冬酰胺酶浓度。本测定方法的线性范围为1～64U/L，灵敏度为0.4U/L。建立的抗体夹心酶联免疫吸附法测定大鼠血浆中重组E.coliL-门冬酰胺酶具有良好的精密度、回收率、灵敏度和特异性。     

Cardiac tamponade due to systemic lupus erythematosus in a 7-year-old boy with selective IgG subclass deficiency

Systemic lupus erythematosus (SLE) was observed in a 7-year-old boy with IgG₂ and IgG₄ subclass deficiencies who had been treated with immunoglobulin (100–200 mg/kg/4 weeks) since 2 years of age. The mother and the half-brother displayed the same deficiency. Serum IgG mainly consisted of IgG₁ (98.9%) during the acute phase of SLE due to transient IgG₃ deficiency. While he had no common manifestations of SLE such as arthritis or nephropathy, he developed cardiac tamponade due to massive pericardial effusion. Conclusion The clinical features of SLE in the present case such as the development of cardiac tamponade and the absence of renal involvement may result from the markedly imbalanced IgG subclass distribution among auto-antibodies. Received: 20 May 1997 and in revised form: 7 October 1997 / Accepted: 21 October 1997     

生姜提取物对X射线损伤免疫功能拮抗作用

目的研究生姜提取物对X射线损伤小鼠免疫功能的拮抗作用。方法实验分为5组,即阳性对照、阴性对照以及3个剂量的生姜提取物组[9.3,4.7,2.3 ml/(kg.bw)]。以不同剂量的生姜提取物给小鼠灌胃后,用剂量为2Gy的X射线照射2次,每次间隔24 h。末次照射结束后48 h处死小鼠,测定脾淋巴细胞转化功能、血清中IgG含量。结果中、低剂量的生姜提取物对X射线引起的小鼠脾淋巴细胞转化功能的损伤有明显的保护作用;高、中、低剂量的生姜提取物对X射线引起IgG的降低均具有拮抗作用。结论适量的生姜提取物对X射线引起的免疫损伤具有保护作用。     

Changes in Anti-SARS-CoV-2 IgG Subclasses over Time and in Association with Disease Severity

IgG is the most prominent marker of post-COVID-19 immunity. Not only does this subtype mark the late stages of infection, but it also stays in the body for a timespan of at least 6 months. However, different IgG subclasses have different properties, and their roles in specific anti-COVID-19 responses have yet to be determined. We assessed the concentrations of IgG1, IgG2, IgG3, and IgG4 against different SARS-CoV-2 antigens (N protein, S protein RBD) using a specifically designed method and samples from 348 COVID-19 patients. We noted a statistically significant association between severity of COVID-19 infection and IgG concentrations (both total and subclasses). When assessing anti-N protein and anti-RBD IgG subclasses, we noted the importance of IgG3 as a subclass. Since it is often associated with early antiviral response, we presumed that the IgG3 subclass is the first high-affinity IgG antibody to be produced during COVID-19 infection.     

Anti‐SARS‐CoV‐2 IgG antibody levels among Thai healthcare providers receiving homologous and heterologous COVID‐19 vaccination regimens

BackgroundWe examined SARS‐CoV‐2 anti‐spike 1 IgG antibody levels following COVID‐19 vaccination (AstraZeneca [AZ], Sinovac [SV], Pfizer‐BioNTech [PZ]) among Thai healthcare providers.MethodsBlood specimens were tested using enzyme‐linked immunosorbent assay. We analyzed seven vaccination regimens: (1) one dose of AZ or SV, (2) two doses of homologous (2AZ, 2SV) or heterologous (1AZ + 1PZ) vaccines, and (3) three doses of heterologous vaccines (2SV + 1AZ, 2SV + 1PZ). Differences in antibody levels were assessed using Kruskal–Wallis statistic, Mann–Whitney test, or Wilcoxon matched‐pairs signed‐rank test. Antibody kinetics were predicted using fractional polynomial regression.ResultsThe 563 participants had median age of 39 years; 92% were female; 74% reported no underlying medical condition. Antibody levels peaked at 22–23 days in both 1AZ and 2SV vaccinees and dropped below assay''s cutoff for positive (35.2 binding antibody units/ml [BAU/ml]) in 55 days among 1AZ vaccinees compared with 117 days among 2SV vaccinees. 1AZ + 1PZ vaccination regimen was highly immunogenic (median 2279 BAU/ml) 1–4 weeks post vaccination. 2SV + 1PZ vaccinees had significantly higher antibody levels than 2SV + 1AZ vaccinees 4 weeks post vaccination (3423 vs. 2105 BAU/ml; p‐value < 0.01), and during weeks 5–8 (3656 vs. 1072 BAU/ml; p‐value < 0.01). Antibodies peaked at 12–15 days in both 2SV + 1PZ and 2SV + 1AZ vaccinees, but those of 2SV + 1AZ declined more rapidly and dropped below assay''s cutoff in 228 days while those of 2SV + 1PZ remained detectable.Conclusions1AZ + 1PZ, 2SV + 1AZ, and 2SV + 1PZ vaccinees had substantial IgG levels, suggesting that these individuals likely mounted sufficient anti‐S1 IgG antibodies for possible protection against SARS‐CoV‐2 infection.     

Anti-SARS CoV-2 IgG in COVID-19 Patients with Hematological Diseases: A Single-center,Retrospective Study in Japan

Objective Coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread globally. Although the relationship between anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies and COVID-19 severity has been reported, information is lacking regarding the seropositivity of patients with particular types of diseases, including hematological diseases. Methods In this single-center, retrospective study, we compared SARS-CoV-2 IgG positivity between patients with hematological diseases and those with non-hematological diseases. Results In total, 77 adult COVID-19 patients were enrolled. Of these, 30 had hematological disorders, and 47 had non-hematological disorders. The IgG antibody against the receptor-binding domain of the spike protein was detected less frequently in patients with hematological diseases (60.0%) than in those with non-hematological diseases (91.5%; p=0.029). Rituximab use was significantly associated with seronegativity (p=0.010). Conclusion Patients with hematological diseases are less likely to develop anti-SARS-CoV-2 antibodies than those with non-hematological diseases, which may explain the poor outcomes of COVID-19 patients in this high-risk group.