Strong and frequent T-cell responses to the minor allergen Phl p 12 in Spanish patients IgE-sensitized to Profilins.

BACKGROUND: Profilins are dominant pan-allergens known to cause cross-sensitization, leading to clinical symptoms such as pollen-food syndrome. This study aimed to determine the T-cell response to Phl p 12 in profilin-sensitized patients, by measuring the prevalence, strength and cross-reactivity to clinically relevant profilins. METHODS: The release of Phl p allergens from pollen was determined by mass spectrometry and immunochemistry. T-cell responses, epitope mapping and cross-reactivity to profilins (Phl p 12, Ole e 2, Bet v 2 and Mal d 4) were measured in vitro using PBMCs from 26 Spanish grass-allergic donors IgE-sensitized to profilin. Cross-reactivity was addressed in vivo using 2 different mouse strains (BALB/c and C3H). RESULTS: Phl p 12 and Phl p 1 are released from pollen simultaneously and in similar amounts. Both T-cell response frequency (17/26 donors) and strength were comparable between Phl p 12 and Phl p 1. T-cell cross-reactivity to other profilins correlated with overall sequence homology, and 2 immunodominant epitope regions of Phl p 12 were identified. Data from mice immunized with Phl p 12 showed that cross-reactivity to Bet v 2 was mediated by conserved epitopes and further influenced by additional genetic factors, likely to be MHC II. CONCLUSION: The strength, prevalence and cross-reactivity of T-cell responses towards Phl p 12 are comparable to the major allergen Phl p 1, which supports the hypothesis that T cells to Phl p 12 can play an important role in development of allergic symptoms, such as those associated with pollen-food syndrome.

Profilin as a severe food allergen in allergic patients overexposed to grass pollen.

BACKGROUND: Profilins are ubiquitous proteins that act as panallergens in sensitized patients, considered to be mild or incomplete food allergens. The aim of the study was to evaluate the role of profilins as severe food allergens in allergic patients overexposed to grass who were referred for severe food reactions and were sensitized to profilins. METHODS: After a careful in vitro screening, 26 patients were included, classified into two groups, mild (17) and severe reactors (9), based on clinical history and subsequently provoked orally with purified profilin in a double-blind placebo-controlled food challenge setup. RESULTS: A significant number of patients presented severe positive food challenge test reactions at low doses of the allergen profilin. Patients prone to suffer from severe reactions had lower IgG4/IgE ratio to major grass allergens than those who did not. CONCLUSION: Profilins are complete food allergens in food-allergic patient populations that are exposed to high levels of grass pollen. This type of patient constitutes an optimal model to understand the link between respiratory and food allergies. The nature of the observed reactions and the low level of allergen eliciting the reactions suggest that intake through the oral mucosa might constitute a relevant route of exposure to food allergens.

A form of apolipoprotein a-I is found specifically in relapses of focal segmental glomerulosclerosis following transplantation.

Recurrence of idiopathic focal segmental glomerulosclerosis (FSGS) following kidney transplantation occurs in a large percentage of patients. Accurate prediction of recurrence and elucidation of its pathogenesis are major therapeutic goals. To detect differential proteins related to FSGS recurrence, proteomic analysis was performed on plasma and urine samples from 35 transplanted idiopathic FSGS patients, divided into relapsing and nonrelapsing. Several proteins were detected increased in urine of relapsing FSGS patients, including a high molecular weight form of apolipoprotein A-I, named ApoA-Ib, found exclusively in relapsing patients. This finding was verified by Western blot individually in the 35 patients and validated in an independent group of 40 patients with relapsing or nonrelapsing FSGS, plus two additional groups: FSGS-unrelated patients showing different proteinuria levels (n = 30), and familial FSGS transplanted patients (n = 14). In the total of 119 patients studied, the ApoA-Ib form was detected in 13 of the 14 relapsing FSGS patients, and in one of the 61 nonrelapsing patients. Only one of the 30 patients with FSGS-unrelated proteinuria tested positive for ApoA-Ib, and was not detected in familial patients. Urinary ApoA-Ib is associated with relapses in idiopathic FSGS and warrants additional investigation to determine its usefulness as biomarker of relapse following transplantation.

A multicenter study of sensitization profiles in an allergic pediatric population in an area with high allergen exposure.

BACKGROUND AND OBJECTIVE: In areas with a high number of allergens and high allergen concentrations, it is essential to identify the main causes of allergy, especially in pediatric patients. This study was conducted in allergic patients aged 14 or less to identify sensitization profiles during an initial phase, and to then evaluate changes in these profiles after 3 years of follow-up. This article describes the first phase of our investigation. METHODS: A total of 187 patients aged between 2 and 14 years were included by 5 allergy units; all the children had symptoms suggestive of allergic disease (rhinoconjunctivitis andlor asthma). Allergy diagnosis was confirmed by evaluation of clinical history, allergen exposure, and in vivo or in vitro tests. Specific immunoglobulin E (slgE) to major allergens was tested. RESULTS: Patients were sensitized to both seasonal (especially grass, olive, cypress and Cynodon dactylon) and perennial allergens (Alternaria alternata) and to panallergens (especially profilin and lipid transfer protein). Almost 60% of the patients included were polysensitized. Sensitization to certain major allergens such as Cup s1, Phl p1, or Sal k1 seems to increase with age. Patients sensitized to profilin had a higher number of sensitizations than non-profilin-sensitized patients. This panallergen is a diagnostic confounding factor. CONCLUSIONS: A high percentage of allergic pediatric patients living in an area with high exposure levels to a large number of allergens are polysensitized and have a high percentage of sensitization to panallergens. The implementation of new diagnostic tools such as component-resolved diagnosis is crucial.

Profilin as an aeroallergen by means of conjunctival allergen challenge with purified date palm profilin.

BACKGROUND: The role of profilin as a food allergen is well established, but little research has been done about its ability to elicit respiratory disease. Profilin is considered more of a confounding allergen on skin testing with whole pollen extracts than other airborne allergens. Our aim was to find out whether or not profilin can cause symptoms in sensitized individuals, which would be compatible with its role as an airborne allergen. METHODS: We performed conjunctival allergen challenges with date palm profilin in a series of consecutive pollen-allergic patients with rhino-conjunctivitis, divided in two groups: profilin sensitized (n = 17) and not sensitized (n = 14), who served as controls. We investigated the possible association between profilin sensitization and profilin allergy in these groups of patients. RESULTS: None of the patients from the not profilin-sensitized group had a positive result in conjunctival allergen challenges. In contrast, 65% of profilin sensitized patients had a positive conjunctival allergen challenge and were considered allergic to profilin. We found a significant statistical association between being profilin allergic and being profilin sensitized (χ(2) = 10.39, p < 0.005). CONCLUSIONS: Profilin seems to work as an aeroallergen in a significant proportion of profilin-sensitized patients. This might explain the uselessness of conjunctival challenges with whole pollen extracts to disclose genuine sensitization. In the future, the possibility of quantifying this allergen in pollen immunotherapy vaccines should be considered.

Efficacy and safety of conversion from twice-daily to once-daily tacrolimus in a large cohort of stable kidney transplant recipients.

Prolonged-release tacrolimus was developed to provide a more convenient once-daily dosing that could improve patient adherence. We conducted a multicenter, prospective, observational, 12-month study to describe the efficacy, safety and patient preference of conversion from tacrolimus twice-daily to once-daily formulation in stable kidney transplant recipients in routine clinical practice. Conversion was made on a 1 mg: 1 mg basis (1 mg: 1.1 mg in patients with trough levels <6 ng/mL). The study included 1832 patients (mean age (± SD): 50.0 ± 13.4 years; 62.7% male). After conversion, a modest reduction in tacrolimus trough levels, necessitating an increase in daily dose, was observed (mean changes at 12 months of -9.1% and +1.24%, respectively; p < 0.0001). Mean glomerular filtration rate did not change significantly (56.5 ± 19.7 mL/min at conversion vs. 55.7 ± 20.6 mL/min at 12 months). Proteinuria, blood pressure, lipid, hepatic and glucose parameters remained stable. Eight patients (0.4%) had acute rejection and 34 patients (1.85%) discontinued treatment. Almost all patients (99.4%) preferred the once-daily formulation, because of less frequent dosing (66%) and improved adherence (34%). In conclusion, at similar doses to twice-daily tacrolimus, once-daily formulation provided stable renal function, a low acute rejection rate, and good tolerability in stable kidney transplant recipients in the routine clinical practice setting.

Preliminary results of a skin prick test-based study of the prevalence and clinical impact of hypersensitivity to pollen panallergens (polcalcin and profilin).

BACKGROUND: Calcium-binding proteins (polcalcins) and profilin are cross-reacting panallergens that sensitize a minority of pollen-allergic patients. Their clinical relevance remains controversial. OBJECTIVE: To assess the clinical relevance of hypersensitivity to polcalcin and profilin detected by skin prick test (SPT) in a large group of pollen-allergic patients. METHODS: Two hundred pollen-allergic adults (101 men, 99 women; mean age 34 years) underwent SPT with 9 pollens present in the geographical area of the study. Hypersensitivity to panallergens was detected by SPT with date palm polcalcin and profilin. Allergy to birch and/or cypress, grass and/or pellitory, and ragweed and/or mugwort were associated with 3 symptomatic periods, respectively, late February to mid-May, late April to mid-July, and mid-August to late September. RESULTS: Sixteen (8%) patients reacted to date palm polcalcin; 7/7 (100%) corecognized the grass polcalcin Phl p 7 in vitro. Clinically, only 4 (25%) had symptoms in all 3 seasonal periods. Forty (20%) patients reacted to profilin; only 32 (80%) reacted to cypress, and 22 (55%) to pellitory. Only 4 (10%) patients had symptoms during all 3 seasonal periods. Six patients (3%) were cosensitized to both polcalcin and profilin. CONCLUSIONS: The clinical relevance of hypersensitivity to pollen panallergens is often limited; many allergic patients have symptoms only during the central period, suggesting primary grass sensitization. Profilin-allergic patients often do not corecognize pellitory and cypress pollen. In vivo component-resolved diagnosis of seasonal respiratory allergies is a promising approach that might lead to cost reduction and a faster definition of pollen-allergic cases.

Component-resolved diagnosis of plant food allergy by SPT.

BACKGROUND: Fruits and vegetables may contain both labile and stable allergens. The former induce only OAS, whereas stable allergens may induce systemic reactions. Component-resolved diagnosis (CRD) of allergy to plant foods is therefore essential for the clinical management of allergic patients. METHODS: 80 adults allergic to plant foods underwent SPT with purified natural date palm profilin (Pho d 2), purified Mal d 1, a peach extract containing uniquely LTP, and with a kiwi extract containing uniquely stable allergens. RESULTS: 58 (72%) patients were monosensitized: 24 to Mal d 1, 24 to profilin, 7 to LTP, and 3 to kiwi. 22 patients were multi-sensitised: 14 to Mal d 1 and profilin, 2 to Mal d 1 and kiwi, 1 to LTP and profilin, 3 to LTP and Mal d 1, and 2 to LTP, Mal d 1 and profilin. Mal d 1 and LTP sensitisation were associated with apple and peach allergy, respectively, whereas profilin sensitisation was associated with allergy to melon, watermelon, banana, tomato and citrus fruits. 18/21 kiwi-allergic patients were sensitised to one of the cross-reacting allergens, but 2/18 reacted to kiwi-specific allergens as well. CONCLUSIONS: In patients with allergy to plant-derived foods CRD can be performed by SPT with purified allergen proteins. In the future, the availability of a larger number of purified natural or recombinant allergens for SPT will represent a simple means to classify food-allergic patients properly on the first visit.

Immunological Mechanisms in Allergic Diseases and Allergen Tolerance: The Role of Treg Cells.

The immune system regulates itself to establish an appropriate immune response to potentially harmful pathogens while tolerating harmless environmental antigens and self-antigens. A central role in this balance is played by regulatory T cells (Tregs) through various ways of actions. By means of molecule secretion and cell-cell contact mechanisms, Tregs may have the capacity to modulate effector T cells and suppress the action of proinflammatory cytokines across a broad range of cell types. As a result, abnormal regulatory T cell function has been pointed as a main cause in the development of allergic diseases, a major public health problem in industrialized countries, with a high socioeconomic impact. This prevalence and impact have created an international interest in improving the allergy diagnosis and therapy. Additionally, research has sought to gain a better understanding of the molecular mechanisms underlining this kind of disease, in order to a better management. At this respect, the role of Treg cells is one of the most promising areas of research, mainly because of their potential use as new immunotherapeutical approaches. Therefore, the aim of this review is to update the existing knowledge of the role of Tregs in this pathology deepening in their implication in allergen-specific therapy (AIT).

Definitive treatment for persistent hypoparathyroidism in a kidney transplant patient: parathyroid allotransplantation.

Post-surgical hypocalcemia is usually a transitory complication in thyroid and parathyroid surgery that can be resolved quickly, although it becomes a delicate matter when the problem persists. Parathyroid transplantation is the choice of treatment; however, the associated immunosuppression can cause side effects. The following case study shows the transplantation of parathyroid tissue from a patient with secondary hyperparathyroidism to another kidney transplant patient with severe hypocalcemia that was medically intractable. The graft is functioning after 2 years.

Iron deficiency--an underrecognized problem in nonanemic and erythrocytic kidney transplant recipients: risks and effects of ACEI and of iron treatment.

The state of iron deposits in long-term kidney graft recipients is not well-known. Angiotensin enzyme inhibitors (ACEIs) reduce hematocrit levels in patients with posttransplant erythrocytosis (PTE), but their action on iron deposits has not been sufficiently evaluated. We designed this study to investigate the prevalence of iron deficiency among patients without anemia, the efficacy of ACEI treatment and its influence on iron deposits, and the risks of iron treatment in patients with symptomatic iron deficiency but no anemia. One hundred thirty eight patients were included if they had a kidney transplant for more than a year, with good renal function, with no anemia, and with neither iron nor rHuEpo, ARA, or ACEI treatment. One hundred seventeen had a normal Ht (group 1) and 21 had PTE (group 2). Iron deficiency was found in 73 (62.4%) group 1 patients and in 10 (47%) group 2 patients. Two group 1 patients with symptoms of iron deficiency were treated with oral iron. Their symptoms disappeared, but one developed PTE. Enalapril treatment decreased Ht levels in PTE but not in control patients. Furthermore, this drug increased iron deposits in PTE and controls with a baseline iron deficiency. We conclude that there is a high prevalence of iron deficiency in long-term transplanted patients without anemia. Furthermore, iron treatment must be carefully administered because of the risk of PTE. Enalapril treatment decreased Ht levels in PTE but not in control patients and increased iron deposits in patients with baseline iron deficiency.

Influence of angiotensin-converting enzyme polymorphism gene, IGF-1, and other factors in the response rate of hematocrit to enalapril treatment in patients with posttransplant erythrocytosis.

A significant relationship between hematocrit values and serum parameters such as the insulin like growth factor (IGF-1) and calcium was observed in patients with posttransplant erythrocytosis (PTE). Since angiotensin-converting enzyme inhibitors (ACEI) decrease hematocrit (Ht) levels in these patients, ACE genotype should play an important role. We designed this study to investigate whether ACE genotype or baseline concentrations of IGF-1, IGF-blood binding protein 3 (BP3), growth hormone (GH), or Ca influenced the response of Ht to ACEI treatment. Twenty-one kidney graft recipients with PTE were treated with enalapril (2.5 to 5 mg/d) for 1 year. IGF-1, BP3, GH, Ca, and Ht were determined before as well as 15, 30, 90, 180, and 365 days after enalapril treatment. ACE polymorphism was also determined. Enalapril treatment significantly decreased Ht levels. Only IGF-1 baseline levels showed a positive correlation to the decreased Ht (P < .025). ACE genotype as determined in 18 patients, showed no correlation with the response to enalapril. Patients with ACE genotype II showed a tendency to an earlier display of PTE. We conclude that low doses of enalapril decrease Ht levels in PTE patients; that PTE begins earlier in patients with II ACE genotype; and that only IGF-1 baseline levels influence the Ht decrease after treatment. These observations suggest that ACEI decrease the Ht via an inhibitory effect on IGF-1, which has a stimulary effect on erythropoiesis.

Detection and treatment of post kidney transplant hyperglycemia: a Spanish multicenter cross-sectional study.

INTRODUCTION: The prevalence of diabetes mellitus (DM) is greater among patients with solid organ transplants than in the general population, although the factors associated with posttransplant DM (PTDM) are unknown. OBJECTIVES: The objective of this study was to estimate the prevalence of and assess the risk factors for PTDM. PATIENTS AND METHODS: We included outpatients with functioning isolated solid organ allografts (kidney, liver, heart, and lung). We collected demographic and posttransplant clinical data that included DM diagnostic ADA criteria, DM treatment, DM family history, presence of hepatitis C virus (HCV), immunosuppression treatment, hypertension, and dyslipidemia. RESULTS: A total of 2178 patients included, 1410 kidney recipients, 489 liver transplants, 207 heart transplants, and 72 lung recipients. Seventeen and four-tenths percent of the patients who did not have DM prior to transplantation, developed PTDM (median time: 79 days). A greater prevalence was observed among patients with a family history, HCV, and tacrolimus treatment (with or without steroids P < .05). By logistic regression analyses, OR for these factors were 1.51, 1.65, and 1.38, respectively. Of those patients who did not suffer PTDM, 55.2% showed basal blood glucose values under 100 mg/dL; only 68% presented with a hemoglobin Alc under 6. CONCLUSIONS: The prevalence of PTDM among kidney recipients was higher than that in the general population. DM family history, HCV positive, and tacrolimus were risk factors associated with this entity.

Monoclonal antibodies against human IgE. Identification of an epitope sharing properties with the high-affinity receptor binding site.

Three monoclonal antibodies to human IgE are described. One of them recognizes an epitope located within a region of 76 amino acids that has been shown to contain the Fc epsilon RI binding site. That epitope is shown to be susceptible to heating and to alkylation of cysteines involved in inter heavy chain bonds, but not to their reduction alone. In addition, this monoclonal antibody, although having a high affinity for free IgE, is unable to bind Fc epsilon RI-linked IgE. Based on these results, we discuss the possibility that the antibody recognizes the Fc epsilon RI binding site of the IgE molecule.

Epitope mapping of beta-lactam antibiotics with the use of monoclonal antibodies.

In order to evaluate the antigenic contribution of different regions of the penicillin molecule, monoclonal antibodies were raised against amoxicillin-protein conjugates and their specificities analysed in detail. A random sample of the clones produced was analysed by a quantitative inhibition-ELISA, using, as inhibitors, monomeric conjugates of the following antibiotics to butylamine (BA), amoxicillin (AX), ampicillin (AMP), benzylpenicillin (BP) and the nuclear part of these, 6-aminopenicillanic acid (6-APA); and different parts of the following molecules: N-(p-hydroxyphenyl)-glycine (PHPG), N-phenylglycine (NPG), phenylacetic acid (PA) and thiazolidine (TIAZ). The results showed that 92% of the antibodies recognized an epitope in which the side chain was a major constituent, although with variable contributions from other regions of the molecule. There was a high degree of crossreactivity with aminopenicillins, but low or absent crossreactivity with BP. None of the antibodies recognized the thiazolidine ring or the conjugated nuclear region of the penicillins. Finally, one antibody seemed to recognize, equally, all the different structures tested. The possible relevance of these results to penicillin allergy is discussed.

C1q-fixing human leukocyte antigen assay in immunized renal patients: correlation between Luminex SAB-C1q and SAB-IgG.

BACKGROUND: There is no consensus about the impact of thresholds of complement-fixing antibody assays. Recently, a C1q-SAB assay has been developed to identify complement-fixing HLA antibodies with high sensitivity and specificity. Our aim was to determine the correlation between IgG single antigens beads (SAB) and C1q-SAB assay results among patients on the renal waiting list. PATIENTS AND METHODS: Serum samples from immunized renal waiting list patients as well as negative and positive controls were valided by Luminex (LMX). These sera, which were positive for 166 antibody specificities, were tested for HLA class I in parallel by LMX-IgG and LMX-C1q. RESULTS: Comparison of antibody detection revealed no correlation based on median fluorescent intensity (MFI), levels between the IgG SAB and the C1qSAB assay (P > .05). IgG-positive sera with MFIs as low as 700 were able to fix C1q, whereas other sera with MFIs as high 14,500 did not. Furthermore, there appeared to be disparities in the profiles of class I antigens able to fix C1q-SAB. In our series, only 34% class I IgG SAB antibodies were also C1qSAB+. In several patients, we detected C1qSAB+ against IgGSAB- that was surely due to IgM antibodies. So, the C1qSAB assay detected IgM antibodies that fix complement. CONCLUSION: These data suggested that the C1q-SAB assay could be an important method to evaluate pretransplant virtual crossmatch and to define nonpermitted specificities (C1q-fixing) in kidney transplantation.