The effectiveness of low-dose of eCG in timed AI Nelore (Bos indicus) heifers

This study evaluated the efficacy of the administration of different doses of equine chorionic gonadotropin (eCG; 0 IU, 200 IU, or 300 IU) at the time of the progesterone device removal in 2-year-old Nelore (Bos indicus) heifers synchronized for fixed-timed artificial insemination (FTAI). On day 0 (D0), a total of 398 heifers received 2 mg of oestradiol benzoate i.m., 0.53 mg of cloprostenol i.m., and an eight-day previously used (second use) intravaginal device containing 1 g of progesterone (P4). Eight days later (D8), simultaneous with the P4 device removal, 0.5 mg of oestradiol cypionate i.m. and 0.53 mg of cloprostenol i.m. were administered. At the same time, heifers were randomly assigned to receive one of the following treatments: G-0 IU (n = 141; no eCG treatment), G-200 IU (n = 132; treated with 200 IU of eCG), and G-300 IU (n = 125; treated with 300 IU of eCG). FTAI was performed 48 h after the P4 device removal (D10). Ultrasonographic evaluations were performed at D0, D10, and D17. Heifers were scanned to measure the size of the largest follicle (LF), the presence, number, and size of the corpus luteum (CL), and the ovulation rate. Subsequently, at D40, the heifers underwent scanning to determine the pregnancy rate and identify any twin pregnancies. Additionally, at D70, scans were performed to assess pregnancy loss (PG). Data were analysed by orthogonal contrasts [C1 (eCG effect): control x (200 IU + 300 IU) and C2 (eCG dose effect): 200 IU × 300 IU]. On D0, CL presence was similar between the groups [G-0 IU = 65.2% (92/141), G-200 IU = 55.3% (73/132), and G-300 IU = 63.2% (79/125); p = .16]. No interactions between the presence of CL on D0 and eCG treatment were found for any of the variables (p > .05). The diameter of the LF at FTAI (D10) was not influenced by eCG treatment (p = .22) or eCG dose (p = .18). However, treatment with eCG increased the diameter of the CL at D17 (G-0 IU = 15.7 ± 0.3 mmb , G-200 IU = 16.6 ± 0.2 mma , and G-300 IU = 16.6 ± 0.3 mma ; p = .001), regardless of the dose used (p = .94). The ovulation rate was higher in heifers treated with eCG [G-0 IU = 79.4%b (112/141), G-200 IU = 90.2%a (119/132), and G-300 IU = 93.6%a (117/125); p = .002], but there was no effect of eCG dose (p = .36). Pregnancy per AI (P/AI) on D40 [G-0 IU = 32.6%b (46/141), G-200 IU = 42.4%a (56/132), and G-300 IU = 42.4%a (53/125); P = 0.05] and D70 [G-0 IU = 29.1%b (41/141), G-200 IU = 40.9%a (54/132), and G-300 IU = 40.8%a (51/125); p = .02] were higher on heifers that received eCG; however, no dose effect was observed for P/AI on D40 (p = .89) nor D70 (p = .98). Pregnancy loss between D40 and D70 tended to reduce (p = .07) in eCG-treated heifers without dose effect (p = .91). Heifers with CL at D0 presented a greater follicle diameter (LF) on D10 (With CL = 11.2 ± 0.2 mm and Without CL = 10.2 ± 0.2 mm; p = .05), CL diameter on D17 (With CL = 15.8 ± 0.03 mm and Without CL = 11.8 ± 0.6 mm; p = .01), and ovulation rate [With CL = 95.5% (233/244) and Without CL = 74.7% (115/154); p = .01]. However, no difference in pregnancy rate at D40 (p = .52) and D70 (p = .84) was found. In conclusion, eCG treatment increases ovulation and pregnancy rates of heifers submitted to a FTAI protocol. Furthermore, eCG treatment increases the diameter of the CL after FTAI and reduces pregnancy losses. No dose effect was observed, suggesting Nelore (Bos indicus) heifers respond to 200 IU of eCG treatment for FTAI.

Pregnancy in Patients With Hereditary Angioedema and Normal C1 Inhibitor

Background

HAE with normal C1 inhibitor (HAE-nC1-INH) has been identified as a bradykinin mediated angioedema. Estrogens are one of the main trigger factors. Pregnancy in HAE with C1 inhibitor deficiency showed variable course, however, few reports are available for HAE-nC1-INH. We evaluated the course of pregnancies in women diagnosed with HAE-nC1-INH.

Methods

Women with diagnosis of HAE-nC1-INH according to the following criteria: clinical manifestations similar to HAE-C1-INH, normal biochemical evaluation and family history were included. A questionnaire about pregnancies was applied after consent. Genetic evaluation for known mutations was performed in all patients.

Results

A total of 45 pregnancies occurring in 26 HAE-nC1-INH patients were evaluated (7/26 patients with F12 variant). Spontaneous abortion was reported in 8/45 (17.8%) pregnancies. Onset of attacks started before the pregnancy in 18/26 patients; during the pregnancy in 2/26; and after the pregnancy in 6/26. HAE attacks occurred in 24/37 pregnancies (64,7%): during the 1st trimester in 41.7%; 2nd trimester in 12.5%; 3rd trimester in 20.8%; 1st and 3rd trimesters in 4.2% and during the whole pregnancy in 20.8%. Among 15/18 patients who had attacks before pregnancy, symptoms persisted with worsening in 9/15; improvement in 4/15; no change in 1/15, and no response in 1/15.

Conclusions

The occurrence of abortion in HAE-nC1-INH was similar to the expected for not affected women. The 1st trimester of the pregnancy was more symptomatic for HAE-nC1-INH women. Considering the strong relevance of estrogens in HAE-nC1-INH, pregnancy could worsen the course of disease.

The global impact of the COVID-19 pandemic on the management and course of chronic urticaria

INTRODUCTION

The COVID-19 pandemic dramatically disrupts health care around the globe. The impact of the pandemic on chronic urticaria (CU) and its management are largely unknown.

AIM

To understand how CU patients are affected by the COVID-19 pandemic; how specialists alter CU patient management; and the course of CU in patients with COVID-19.

MATERIALS AND METHODS

Our cross-sectional, international, questionnaire-based, multicenter UCARE COVID-CU study assessed the impact of the pandemic on patient consultations, remote treatment, changes in medications, and clinical consequences.

RESULTS

The COVID-19 pandemic severely impairs CU patient care, with less than 50% of the weekly numbers of patients treated as compared to before the pandemic. Reduced patient referrals and clinic hours were the major reasons. Almost half of responding UCARE physicians were involved in COVID-19 patient care, which negatively impacted on the care of urticaria patients. The rate of face-to-face consultations decreased by 62%, from 90% to less than half, whereas the rate of remote consultations increased by more than 600%, from one in 10 to more than two thirds. Cyclosporine and systemic corticosteroids, but not antihistamines or omalizumab, are used less during the pandemic. CU does not affect the course of COVID-19, but COVID-19 results in CU exacerbation in one of three patients, with higher rates in patients with severe COVID-19.

CONCLUSIONS

The COVID-19 pandemic brings major changes and challenges for CU patients and their physicians. The long-term consequences of these changes, especially the increased use of remote consultations, require careful evaluation.

Brazilian Guidelines for Hereditary Angioedema Management - 2017 Update Part 1: Definition, Classification and Diagnosis

Hereditary angioedema is an autosomal dominant disease characterized by recurrent angioedema attacks with the involvement of multiple organs. The disease is unknown to many health professionals and is therefore underdiagnosed. Patients who are not adequately diagnosed and treated have an estimated mortality rate ranging from 25% to 40% due to asphyxiation by laryngeal angioedema. Intestinal angioedema is another important and incapacitating presentation that may be the main or only manifestation during an attack. In this article, a group of experts from the "Associação Brasileira de Alergia e Imunologia (ASBAI)" and the "Grupo de Estudos Brasileiro em Angioedema Hereditário (GEBRAEH)" has updated the Brazilian guidelines for the diagnosis and treatment of hereditary angioedema.

Hereditary angioedema: quality of life in Brazilian patients

OBJECTIVE

Hereditary angioedema is a serious medical condition caused by a rare autosomal dominant genetic disorder and it is associated with deficient production or dysfunction of the C1 esterase inhibitor. In most cases, affected patients experience unexpected and recurrent crises of subcutaneous, gastrointestinal and laryngeal edema. The unpredictability, intensity and other factors associated with the disease impact the quality of life of hereditary angioedema patients. We evaluated the quality of life in Brazilian hereditary angioedema patients.

METHODS

Patients older than 15 years with any severity of hereditary angioedema and laboratory confirmation of C1 inhibitor deficiency were included. Two questionnaires were used: a clinical questionnaire and the SF-36 (a generic questionnaire). This protocol was approved by the Ethics Committee of Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo.

RESULTS

The SF-36 showed that 90.4% (mean) of all the patients had a score below 70 and 9.6% had scores equal to or higher than 70. The scores of the eight dimensions ranged from 51.03 to 75.95; vitality and social aspects were more affected than other arenas. The internal consistency of the evaluation was demonstrated by a Cronbach's alpha value above 0.7 in seven of the eight domains.

CONCLUSIONS

In this study, Brazilian patients demonstrated an impaired quality of life, as measured by the SF-36. The most affected domains were those related to vitality and social characteristics. The generic SF-36 questionnaire was relevant to the evaluation of quality of life; however, there is a need for more specific instruments for better evaluation.

C1 Esterase Inhibitor (Human) for the Treatment of Acute Hereditary Angioedema

Hereditary angioedema (HAE) is a relatively rare disease characterized by acute episodes of swelling. These swellings can be disfiguring, painful and life-threatening. Since the symptoms occur in different areas and most patients experience a delay in their diagnosis, resulting in unnecessary suffering and dangerous situations. HAE can have a tremendous impact on the quality of life. The major genetic deficiency in this disorder is either an absent or nonfunctional C1INH which regulates the complement, fibrinolitic, kalikrein and plasmin pathways.

Brazilian guidelines for the diagnosis and treatment of hereditary angioedema

Hereditary angioedema is an autosomal dominant disease characterized by edema attacks with multiple organ involvement. It is caused by a quantitative or functional deficiency of the C1 inhibitor, which is a member of the serine protease inhibitor family. Hereditary angioedema is unknown to many health professionals and is therefore an underdiagnosed disease. The causes of death from hereditary angioedema include laryngeal edema with asphyxia. The estimated mortality rate in patients in whom the disease goes undetected and who are therefore incorrectly treated is 25-40%. In addition to edema of the glottis, hereditary angioedema often results in edema of the gastrointestinal tract, which can be incapacitating. Patients with hereditary angioedema may undergo unnecessary surgical interventions because the digestive tract can be the primary or only organ system involved, thus mimicking acute surgical abdomen. It is estimated that patients with hereditary angioedema experience some degree of disability 20-100 days per year. The Experts in Clinical Immunology and Allergy of the "Associação Brasileira de Alergia e Imunopatologia -ASBAI" developed these guidelines for the diagnosis, therapy, and management of hereditary angioedema.

Endophytic and entomopathogenic strains of Beauveria sp to control the bovine tick Rhipicephalus (Boophilus) microplus

Pathogenicity of strains of the entomopathogenic fungus Beauveria bassiana and endophytic strains of Beauveria sp against the bovine tick Rhipicephalus (Boophilus) microplus was tested in laboratory bioassays and under field conditions. Suspensions containing 10(5), 10(7) and 10(9) conidia/mL were prepared of each fungal strain for laboratory bioassays. The ticks were maintained at 28 degrees C, 90 +/- 5% relative humidity, and the following variables were evaluated: initial female weight, egg weight, hatching percentage, reproductive efficiency, and percentage control. For tests under field conditions, a Beauveria suspension containing 10(6) conidia/mL was sprayed on tick-infested cows. After 72 h, the ticks were collected to estimate mortality under field conditions. Laboratory bioassays showed a mortality of 20 to 50% of the ticks seven days after inoculation with 10(7) Beauveria conidia/mL. Under field conditions 10(6) Beauveria conidia/mL induced 18-32% mortality. All Beauveria strains were effective in biological control of R. (Boophilus) microplus under laboratory and field test conditions. This is the first demonstration that endophytic fungi can be used for biological control of the cattle tick; this could help reduce environmental contamination by diminishing the need for chemical acaricides. Two endophytic strains were isolated from maize leaves and characterized by molecular sequencing of 5.8S rDNA ITS1 and ITS2 and morphological analyses of conidia. We found that these two endophytic Beauveria isolates, designated B95 and B157, are close to Beauveria amorpha.

Immunomodulation of the allergic inflammatory response: new developments

Studies of the molecular mechanisms associated with allergic diseases have lead to a better understanding of the complex processes that underlie their pathogenesis. These mechanisms involve Th2- and Th1-type cells and also some recently described cytokines, such as IL-25 and IL-33. Regulatory mechanisms of allergic inflammation have also been identified. For instance, IL-10, a cytokine produced by many cell types, promotes a decrease in IgE production, and inhibits the release of histamine and other inflammatory mediators by mast cells. Recently, a variety of regulatory cells have been discovered, which, either by direct contact or through the production of IL-10 and/or TGF-beta, can inhibit the allergic inflammatory response. IL-10 is produced in high levels by cells of helminth-infected individuals. There is some evidence that such infections protect against the development of allergic diseases. In asthmatic individuals living in endemic areas of schistosomiasis, it has been shown in in vitro studies that there is a modulation of the Th2 response, both by mechanisms involving IL-10, which is produced mainly by monocytes and CD4+CD25+ T regulatory cells, and also by the expression of cytotoxic T-lymphocyte antigen 4 (CTLA-4) in CD4+ T cells. Studies using parasite antigens to induce the modulation of allergic inflammatory response are being conducted by several groups of researchers and represent new perspectives for the treatment of allergic diseases.

Futura study: evaluation of efficacy and safety of rupatadine fumarate in the treatment of persistent allergic rhinitis

Allergic rhinitis affects 10-30% of the population, negatively impacting one's quality of life and productivity. It has been associated with sinusitis, otitis media, sleep disorders, and asthma. Rupatadine is a second generation antihistamine with increased affinity to histamine receptor H1; it is also a potent PAF (platelet-activating factor) antagonist. It starts acting quite quickly, offers long lasting effect, and reduces the chronic effects of rhinitis.

AIM

this study aims to assess the efficacy and safety of rupatadine in the treatment of persistent allergic rhinitis.

MATERIALS AND METHOD

this is a multi-centric open prospective study. This study included 241 patients from 13 centers in Brazil and was held between October of 2004 and August of 2005. Signs and symptoms of rhinitis and tolerance to medication were analyzed after one and two weeks of treatment.

RESULTS

reduction on general scores from 8.65 to 3.21 on week 2 (p<0.001). All signs and symptoms improved significantly in the first day of treatment (p<0.001), except for nasal congestion and secretion, which improved from the second day of treatment (p<0.001). Adverse events occurred in 19.9% of the cases, 27.7% on week 1.

CONCLUSION

rupatadine effectively controls persistent allergic rhinitis; it is safe and presents low incidence of side effects.

FUTURA STUDY-Evaluation of efficacy and safety of rupatadine fumarate in the treatment of persistent allergic rhinitis

Allergic rhinitis affects 10-30% of the population, negatively impacting one's quality of life and productivity. It has been associated with sinusitis, otitis media, sleep disorders, and asthma. Rupatadine is a second generation antihistamine with increased affinity to histamine receptor H1; it is also a potent PAF (platelet-activating factor) antagonist. It starts acting quite quickly, offers long lasting effect, and reduces the chronic effects of rhinitis.

Aim

this study aims to assess the efficacy and safety of rupatadine in the treatment of persistent allergic rhinitis.

Materials and method

this is a multi-centric open prospective study. This study included 241 patients from 13 centers in Brazil and was held between October of 2004 and August of 2005. Signs and symptoms of rhinitis and tolerance to medication were analyzed after one and two weeks of treatment.

Results

reduction on general scores from 8.65 to 3.21 on week 2 (p<0.001). All signs and symptoms improved significantly in the first day of treatment (p<0.001), except for nasal congestion and secretion, which improved from the second day of treatment (p<0.001). Adverse events occurred in 19.9% of the cases, 27.7% on week 1.

Conclusion

rupatadine effectively controls persistent allergic rhinitis; it is safe and presents low incidence of side effects.

Invariant NKT cells rapidly activated via immunization with diverse contact antigens collaborate in vitro with B-1 cells to initiate contact sensitivity

In cutaneous contact sensitivity there is an early elicited innate cascade of complement, mast cells, and platelets activated via IgM Abs. This response is required to initiate the elicitation of acquired classical contact sensitivity by leading to local recruitment of effector T cells. We recently performed in vivo experiments showing that collaboration is required between innate-like invariant Valpha14+ NKT cells (iNKT) and the innate-like B-1 B cell subset to induce this initiation process. Contact sensitization triggers iNKT cells to produce IL-4 to coactivate the B-1 cells along with specific Ag for production of the initiating IgM Abs. We now describe in vitro collaboration of iNKT and B-1 cells. Normal peritoneal B-1 cells, incubated in vitro with soluble Ag, and with 1-h in vivo immune iNKT cells producing IL-4, are activated to mediate the contact sensitivity-initiation cascade. The three components of this process can be activated by different Ag. Thus, 1-h iNKT cell activation, B-1 cell stimulation, and generation of immune effector T cells can be induced by sensitization with three different Ag to respectively generate IL-4 and Ag-specific IgM Abs, to recruit the Ag-specific effector T cells. These findings have relevance to allergic and autoimmune diseases in which infections can trigger exacerbation of T cell responses to allergens or to autoantigens.

Interleukin-4-dependent innate collaboration between iNKT cells and B-1 B cells controls adaptative contact sensitivity

We showed that hepatic Valpha14+ invariant natural killer T (iNKT) cells, via their rapid interleukin (IL)-4 production, activate B-1 cells to initiate contact sensitivity (CS). This innate collaboration was absent in IL-4(-/-) and signal transducer and activator of transcription (STAT)-6(-/-) mice and was inhibited by anti-IL-4 treatment. These mice have defective CS because they fail to locally recruit the sensitized effector T cells of acquired immunity. Their CS is reconstituted by transfer of downstream-acting 1-day immune B-1 cells from wild-type mice. Responses were not reconstituted with B-1 cells from IL-4 receptor-alpha(-/-) or STAT-6(-/-) mice, nor by IL-4 treatment of B cell-deficient mice at immunization. Finally, IL-4 was preferentially and transiently produced by hepatic iNKT cells within 7 min after sensitization to mediate collaboration between innate-like iNKT cells and the B-1 B cells that participate in the recruitment of effector T cells in vivo.

An hour after immunization peritoneal B-1 cells are activated to migrate to lymphoid organs where within 1 day they produce IgM antibodies that initiate elicitation of contact sensitivity

Elicitation of contact sensitivity (CS), a classic example of T cell-mediated immunity, requires Ag-specific IgM Abs to trigger an initiation process. This early process leads to local recruitment of CS-effector T cells after secondary Ag challenge. These Abs are produced by the B-1 subset of B cells within 1 day after primary skin immunization. In this study we report the surprising observation that B-1 cells in the peritoneal cavity are activated as early as 1 h after naive mice are painted with a contact-sensitizing Ag on the skin of the trunk and feet to begin the initiation of CS. B-1 cells in the spleen and draining lymph nodes produce the initiating Abs by 1 day after immunization, when we found increased numbers of Ag-specific IgM Ab-producing cells in these tissues by ELISPOT assay. Importantly, we show that contact-activated peritoneal B-1 cells migrate to these lymphoid tissues and then differentiate into Ag-specific IgM Ab-producing cells, resulting in specific CS-initiating IgM Abs in the serum by 1 day. Furthermore, pertussis toxin, which is known to inhibit signaling via G protein-coupled chemokines, inhibited the migration of contact-activated peritoneal B-1 cells to the lymphoid tissues, probably due to BLR-1 (Burkitt lymphoma receptor-1). These findings indicate that within 1 h after contact skin immunization, B-1 cells in the peritoneal cavity are activated to migrate to the lymphoid tissues by chemokine-dependent mechanisms to produce serum Ag-specific IgM Abs within 1 day after immunization, leading to local recruitment of CS-effector T cells.

Airway hyper-reactivity mediated by B-1 cell immunoglobulin M antibody generating complement C5a at 1 day post-immunization in a murine hapten model of non-atopic asthma

Contact skin immunization of mice with reactive hapten antigen and subsequent airway challenge with the same hapten induces immediate airflow obstruction and subsequent airway hyper-reactivity (AHR) to methacholine challenge, which is dependent on B cells but not on T cells. This responsiveness to airway challenge with antigen is elicited as early as 1 day postimmunization and can be adoptively transferred to naïve recipients via 1-day immune cells. Responses are absent in 1-day immune B-cell-deficient JH(-/-) mice and B-1 B-cell-deficient xid male mice, as well as in recipients of 1-day immune cells depleted of cells with the B-1 cell phenotype (CD19(+) B220(+) CD5(+)). As B-1 cells produce immunoglobulin M (IgM), we sought and found significantly increased numbers of anti-hapten IgM-producing cells in the spleen and lymph nodes of 1-day immune wild-type mice, but not in xid mice. Then, we passively immunized naive mice with anti-hapten IgM monoclonal antibody and, following airway hapten challenge of the recipients, we showed both immediate airflow obstruction and AHR. In addition, AHR was absent in complement C5 and C5a receptor-deficient mice. In summary, this study of the very early elicited phase of a hapten asthma model suggests, for the first time, a role of B-1 cells in producing IgM to activate complement to rapidly mediate asthma airway reactivity only 1 day after immunization.

Early delayed-type hypersensitivity eosinophil infiltrates depend on T helper 2 cytokines and interferon-gamma via CXCR3 chemokines

We investigated the role of T helper (Th)1- and Th2-type cytokines in delayed-type hypersensitivity to soluble protein antigens elicited early postimmunization. Mice were sensitized by intradermal injection without adjuvants, or subcutaneously with complete Freund's adjuvant, and subsequently ear challenged intradermally. As soon as day 3, antigen-specific eosinophil-rich responses were elicited in wild-type mice, but not in T-cell receptor-alpha-/- mice without adjuvant. Draining lymph node T cells stimulated with antigen secreted interleukin (IL)-4, IL-5 and interferon-gamma (IFN-gamma). IFN-gamma-dependent specific immunoglobulin G (IgG)2a and IL-4-dependent IgG1 were also generated. Delayed-type hypersensitivity ear swelling and local eosinophil recruitment were decreased in IL-5-/-, IL-4-/- and signal transducer and activator of transcription-6 (STAT-6)-/- mice, and with anti-IL-4 treatment of wild-type mice, suggesting Th2 mechanisms. Interestingly, responses were also decreased in IFN-gamma-/- mice, and IFN-gamma protein and the IFN-gamma-inducible CXC chemokine, IP-10, were present in 24-hr ear tissue extracts, suggesting Th1 effects. Finally, ear swelling, total histology and eosinophils were decreased in mice deficient in CXCR3, the chemokine receptor for IP-10. These results suggest that both a Th2-like (IL-5, IL-4 and STAT-6) and a Th1-like (IFN-gamma, IP-10, CXCR3) pathway contribute to eosinophil recruitment in early delayed-type hypersensitivity.

Cutaneous immunization rapidly activates liver invariant Valpha14 NKT cells stimulating B-1 B cells to initiate T cell recruitment for elicitation of contact sensitivity

T cell recruitment to elicit contact sensitivity (CS) requires a CS-initiating process mediated by B-1 cells that produce IgM, which activates complement to promote T cell passage into the tissues. We now show that Vα14i NKT cells induce B-1 cell activation likely by releasing IL-4 early postimmunization. The CS initiation process is absent in Jα18^−/− and CD1d^−/− NKT cell–deficient mice and is reconstituted by populations enriched for Vα14i NKT cells. Transfers are not effective if cells are derived from IL-4^−/− mice. Staining with specific tetramers directly showed that hepatic Vα14i NKT cells increase by 30 min and nearly double by 2 h postimmunization. Transfer of immune B-1 cells also reconstitutes CS responses in NKT cell–deficient mice. The B-1 cells act downstream of the Vα14i NKT cells to restore CS initiation. In addition, IL-4 given systemically to Jα18^−/− or CD1d^−/− NKT cell–deficient mice reconstitutes elicitation of CS. Further, splenocytes from immune Jα18^−/− mice produce less antigen (Ag)-specific IgM antibodies compared with sensitized WT mice. Together these findings indicate that very early after skin immunization Vα14i NKT cells are stimulated to produce IL-4, which activates B-1 cells to produce Ag-specific IgM, subsequently needed to recruit effector T cells for elicitation of CS responses.

B-1 B Cells Mediate Required Early T Cell Recruitment to Elicit Protein-Induced Delayed-Type Hypersensitivity

We define the initiation of elicited delayed-type hypersensitivity (DTH) as a series of processes leading to local extravascular recruitment of effector T cells. Responses thus have two sequential phases: 1) 2-h peaking initiation required for subsequent recruitment of T cells, and 2) the late classical 24-h component mediated by the recruited T cells. We analyzed DTH initiation to protein Ags induced by intradermal immunization without adjuvants. Ag-spceific initiating cells are present by 1 day in spleen and lymph nodes. Their phenotypes, determined by depletion of cell transfers by mAb and complement, are CD5(+), CD19(+), CD22(+), B220(+), Thy1(+), and Mac1(+), suggesting that they are B-1 B cells. DTH initiation is absent in micro MT B cell and xid B-1 cell deficient mice, is impaired in mice unable to secrete IgM, and is reconstituted with 1 day immune serum, suggesting that early B-1 cell-derived IgM is responsible. Study of complement C5a receptor-deficient mice, anti-C5 mAb neutralization, or mast cell deficiency suggests that DTH initiation depends on complement and mast cells. ELISPOT assay confirmed production of Ag-specific IgM Abs at days 1 and 4 in wild-type mice, but not in B-1 cell-deficient xid mice. We conclude that rapidly activated B-1 cells produce specific IgM Abs which, after local secondary skin challenge, form Ag-Ab complexes that activate complement to generate C5a. This stimulates C5a receptors on mast cells to release vasoactive substances, leading to endothelial activation for the 2-h DTH-initiating response, allowing local recruitment of DTH-effector T cells.

B cell-dependent T cell responses: IgM antibodies are required to elicit contact sensitivity

Contact sensitivity (CS) is a classic example of in vivo T cell immunity in which skin sensitization with reactive hapten leads to immunized T cells, which are then recruited locally to mediate antigen-specific inflammation after subsequent skin challenge. We have previously shown that T cell recruitment in CS is triggered by local activation of complement, which generates C5a that triggers C5a receptors most likely on mast cells. Here, we show that B-1 cell-derived antihapten IgM antibodies generated within 1 day (d) of immunization combine with local challenge antigen to activate complement to recruit the T cells. These findings overturn three widely accepted immune response paradigms by showing that (a) specific IgM antibodies are required to initiate CS, which is a classical model of T cell immunity thought exclusively due to T cells, (b) CS priming induces production of specific IgM antibodies within 1 d, although primary antibody responses typically begin by day 4, and (c) B-1 cells produce the 1-d IgM response to CS priming, although these cells generally are thought to be nonresponsive to antigenic stimulation. Coupled with previous evidence, our findings indicate that the elicitation of CS is initiated by rapidly formed IgM antibodies. The IgM and challenge antigen likely form local complexes that activate complement, generating C5a, leading to local vascular activation to recruit the antigen-primed effector T cells that mediate the CS response.

Subunits of IgM reconstitute defective contact sensitivity in B-1 cell-deficient xid mice: kappa light chains recruit T cells independent of complement

The elicitation of contact sensitivity (CS) to local skin challenge with the hapten trinitrophenyl (TNP) chloride requires an early process that is necessary for local recruitment of CS-effector T cells. This is called CS initiation and is due to the B-1 subset of B cells activated at immunization to produce circulating IgM Ab. At challenge, the IgM binds hapten Ag in a complex that locally activates C to generate C5a that aids in T cell recruitment. In this study, we present evidence that CS initiation is indeed mediated by C-activating classic IgM anti-TNP pentamer. We further demonstrate the involvement of IgM subunits derived either from hybridomas or from lymphoid cells of actively immunized mice. Thus, reduced and alkylated anti-TNP IgM also initiates CS, likely due to generated H chain-L chain dimers, as does a mixture of separated H and L chains that still could weakly bind hapten, but could not activate C. Remarkably, anti-TNP kappa L chains alone mediated CS initiation that was C-independent, but was dependent on mast cells. Thus, B-1 cell-mediated CS initiation required for T cell recruitment is due to activation of C by specific IgM pentamer, and also subunits of IgM, while kappa L chains act via another C-independent but mast cell-dependent pathway.

Drug use in an intensive care unit and its relations to survival

Admissions during the first 6 months of 1978, 427 in all, have been reviewed in relation to their pharmacological treatment and mortality rates. They have been divided into five groups according to their diagnoses, and for mortality evaluation. Tagge's prognostic classification was applied. Length of stay, number of drugs used in each patient, and cost of pharmacological therapy, do not have a significant relation to survival. Conclusions stress the great importance of determining uniform admission criteria to evaluate the degree of effort in money, personnel and hospital support to be spent on these kind of patients.