The mechanisms of serum-treated zymosan (STZ)-induced oxidative metabolism by human eosinophils and the effects of IL-5 priming.

BACKGROUND: The aim of this work was to study the mechanisms of action of IL-5 on the subsequent stimulation of the oxidative metabolism of blood eosinophils by serum-treated zymosan (STZ), in terms of signal transduction characteristics, and by comparing the response of cells from healthy and allergic subjects during environmental exposure to birch pollen. METHODS: Eosinophils from healthy controls and allergic patients were purified to over 95% by Percoll gradients and the MACS system. Oxidative metabolism was measured by a lucigenin-enhanced chemiluminescence (CL) assay. Eosinophils were primed with IL-5 and subsequently stimulated with STZ. The signal transduction mechanisms of IL-5 priming were studied with the MEK inhibitor PD 98059,the PkC inhibitors staurosporine and Ro 318220, and the PI3 kinase inhibitor wortmannin. RESULTS: IL-5 increased the maximum radical production (P=0.0079) and reduced the t(1/2) rise (0.000018) of the CL reactions. The t(1/2) rise was PkC dependent and MEK independent, while the maximum radical production was PkC, MEK, and PI3 kinase dependent. During the pollen season, IL-5 reduced the total STZ-induced CL response in the patients' cells (P=0.016), but not in the control cells, whereas it primed the response to STZ of both cell populations in terms of the t(1/2) rise (P=0.012 and 0.00066, respectively). CONCLUSION: STZ-induced oxidative metabolism consists of different stages. The initial stage (t(1/2) rises of the curves) is PkC dependent and MEK independent, while the end stage (maximum radical production) is PkC, MEK, and PI3 kinase dependent. IL-5 shortened the initial stage, and increased the end stage. During allergen exposure, however, the end stage was reduced by IL-5. This could be due to increased amounts of hypodense eosinophils and/or some abnormality in cell responses.

New reference values for routine blood samples and human neutrophilic lipocalin during third-trimester pregnancy.

Reference values are usually based on blood samples from healthy men or non-pregnant women. Blood samples from pregnant women may be compared with these reference values. Correct references for pregnancy can be extremely important for clinical decisions such as ablatio placentae, appendicitis, premature rupture of membranes and preeclampsia. Previous studies of normal variations during third-trimester pregnancy are incomplete. Blood samples during pregnancy weeks 33, 36 and 39 as well as 1-3 h postpartum were collected from pregnant women with dietary iron supplement and at least one previous pregancy without a history of hypertension or preeclampsia. When the sampled values were compared with the present reference values from men and non-pregnant women, the following differences were found during normal pregnancy: Haemoglobin and ferritin were reduced, CRP was slightly elevated, WBC (white blood cell count) and HNL (human neutrophilic lipocalin) were elevated during pregnancy and significantly increased postpartum. Albumin was reduced. ALT and AST were slightly elevated and GGT was unchanged during pregnancy. ALP, D-dimer and fibrinogen were elevated. Uric acid increased during the third trimester and thrombocyte count decreased. Separate reference values for pregnant women are essential for correct diagnostic decisions during third-trimester pregnancy. Elevated levels of D-dimer do not necessarily indicate ablatio placentae. A diagnosis of progressive preeclampsia cannot be based on increasing uric acid levels and reduced platelet count in a stable clinical condition. HNL signals activation of neutrophilic granulocytes and can thereby offer a helpful tool for diagnosing infection during pregnancy and postpartum.

Activation of B-lymphocytes during pollen season. Effect of immunotherapy.

BACKGROUND: B-lymphocytes play an important part in the allergic reaction as producers of IgE antibodies. OBJECTIVE: To investigate the cell surface expression of the activation antigens CD23, CD40 and HLA-DR on B-lymphocytes in birch pollen allergic patients before and during birch pollen season and to study the effect of immunotherapy. METHODS: The study included 24 birch pollen allergic patients half of whom were treated with immunotherapy against birch pollen before the start of the season. Eleven of the 24 patients had asthma. Blood samples were taken and lung function was registered before the season began and before the immunotherapy treatment in January to February and during the season in May. The relative number of B-lymphocytes (CD19+) of the lymphocyte population and the cell surface expression of CD23, CD40 and HLA-DR on B-lymphocytes was measured by the use of flow cytometry. RESULTS: In the control group of patients the relative number and concentration of B-lymphocytes, the cell surface expression of CD23, CD40 and HLA-DR on B cells, and the serum concentration of IgE increased during season compared with before season. In contrast, in the immunotherapy treated patients no changes in the number of B cells or cell surface expression of CD23, CD40 and HLA-DR were demonstrated. CONCLUSION: The elevated expression of CD23, CD40 and HLA-DR on B cells, combined with increased levels of IgE in allergic patients during season could be explained by the effect of cytokines produced by activated TH2 cells. A shift from TH2 to TH1 cells might be the mechanism after the absence of signs of B-cell activation in immunotherapy treated patients. The prevention of increased cell surface expression on B cells by immunotherapy may constitute a significant mechanism behind the beneficial effects of immunotherapy in the treatment of pollen atopy.

Blood eosinophils from asymptomatic allergics have a reduced capacity to produce oxygen-free radicals.

BACKGROUND: The eosinophil granulocyte is an inflammatory cell that plays an active part in diseases such as asthma and rhinitis. This study aimed to investigate oxidative metabolism by blood eosinophils taken from allergic rhinitis patients, asthmatics, and nonallergic controls before and during the birch-pollen season. METHODS: Twenty patients with allergy to birch pollen and seasonal symptoms of rhinitis, some of whom were also asthmatic, were followed before and during the birch-pollen season in Sweden. The cells were purified using a Percoll gradient and the MACS system. Eosinophil purity in all samples was > 95%. Oxidative metabolism was measured by a chemiluminescence (CL) assay, with luminol and lucigenin acting as enhancers, and PMA, serum-treated zymosan (STZ), interleukin (IL)-5, or RANTES as stimuli. RESULTS: The allergic subjects showed reduced luminol CL when activated before the season with PMA (P = 0.040) or STZ (P = 0.0055). This was not seen during pollen exposure. STZ-activated lucigenin CL was also reduced before the season (P = 0.0027). The reduction was most evident in the group with asymptomatic rhinitis. In terms of eosinophil stimulation, IL-5 and RANTES were equally effective in allergic and nonallergic subjects, both before and during the pollen season. CONCLUSIONS: Blood eosinophils from asymptomatic allergics may have a lower capacity to produce oxygen-free radicals than eosinophils from nonallergics.

Influence of two blood conservation techniques (cardiotomy reservoir versus cell-saver) on biocompatibility of the heparin coated cardiopulmonary bypass circuit during coronary revascularization surgery.

Blood conservation during cardiac surgery is critically important because of the inherent risks in homologous blood transfusions. Two techniques for the intraoperative conservation of blood--retransfusion of the red cells using a cell-saver (CS), or retransfusion of the blood using a cardiotomy suction (CTR) system--were compared using biocompatibility markers, granulocyte activation, and production of oxygen-free radicals (OFR). In the CTR group, heparin coated circuits with an uncoated cardiotomy reservoir were used. For the CS group, identical heparin coated cardiopulmonary bypass (CPB) sets, without a cardiotomy reservoir but with a CS, were used. In each group, eight patients had coronary artery bypass grafting performed. The capacity of the whole blood and the granulocytes to produce OFR was estimated by a chemiluminescence, and granulocyte activation was measured as release of the granulocyte granule proteins myeloperoxidase (MPO) and lactoferrin. A significantly reduced capacity to produce OFR by the whole blood was noted at 45 minutes of CPB in the CTR group (68% +/- 17% vs 94% +/- 16% in the CS group). MPO release was higher after 3 hours (p = 0.05) and 20 hours (p < 0.05), postoperatively, in the CTR group (417 +/- 77 micrograms/L and 257 +/- 31 micrograms/L vs 246 +/- 25 micrograms/L and 164 +/- 12 micrograms/L, respectively, in the CS group). We conclude that the heparin coated CPB circuit with the uncoated cardiotomy reservoir may be less biocompatible than the identical CPB set used together with the CS.

Priming of eosinophil adhesion in patients with birch pollen allergy during pollen season: effect of immunotherapy.

The adhesion of eosinophil granulocytes to E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) was investigated before and during birch pollen season in 24 patients allergic to birch pollen who had rhinoconjunctivitis and, in half of the cases, asthma during season. Half of the patients were undergoing specific immunotherapy for birch pollen allergy. Increased adhesion to VCAM-1 and ICAM-1 (p < 0.05) during season as compared with before season was demonstrated by eosinophils of patients in the control group and by eosinophils of the patients without asthma treated with immunotherapy, but not by eosinophils from the immunotherapy-treated patients with asthma. Eosinophils from the control group of patients demonstrated increased cell surface expression of CD18 and CD49d (p < 0.05 and p < 0.01, respectively) during season as compared with before season, and eosinophils from the immunotherapy-treated patients showed increased cell surface expression of CD49d (p < 0.01) during season. Simultaneous measurement of neutrophil adhesion revealed increased adhesion to E-selectin and ICAM-1 (p < 0.01) during season compared with before season in the immunotherapy-treated group of patients. Neutrophils from the control subjects without asthma showed increased adhesion to E-selectin (p < 0.05) during season. In conclusion, eosinophils from patients allergic to birch pollen demonstrated priming of the adhesion to VCAM-1 to ICAM-1 during birch pollen season. Immunotherapy treatment prevented the priming of eosinophil adhesion during pollen season in the patients allergic to birch pollen who had asthma, but not in those without asthma. In contrast, neutrophils from the immunotherapy-treated patients, both with and without asthma, demonstrated priming of the adhesion to E-selectin and ICAM-1 during season. The latter results indicate that immunotherapy, in case of the patients allergic to birch pollen with asthma induced a shift from the production of primarily eosinophil priming agents to primarily neutrophil priming agents, which may be caused by a shift from Th2 to Th1 lymphocytes.

Oxygen radical production by blood eosinophils is reduced during birch pollen season in allergic patients.

BACKGROUND: The eosinophil granulocyte takes part in allergic inflammatory diseases, like asthma and rhinitis. The aim of this study was to investigate the oxidative metabolism of the blood eosinophils and neutrophils from birch pollen allergic patients, during and after exposure to their allergen. METHODS: Thirteen birch pollen allergic patients, with seasonal symptoms of rhinitis, with or without asthma, were followed. The cells were purified using a percoll gradient and the MACS system. The eosinophil purity in all samples was > 95%. The oxidative metabolism of both the PMN and the eosinophils was measured by means of a chemiluminescence (CL) assay, with luminol or lucigenin as the amplifier, and using PMA (16 nM) as the activator. RESULTS: In relative terms, the lucigenin CL by the eosinophils was 5-10-fold higher than that of the PMN, P = 0.002. The eosinophils of the birch pollen allergic patients produced less oxygen radicals during the season, compared to the reference group, measured both with luminol CL and lucigenin CL, P = 0.01 and P = 0.02 respectively. Out of season, there was no difference. There was also no difference, during either period, between patients and references in PMN CL. Separating the eosinophils into hypodense and normodense fractions, showed a decreased oxidative metabolism by the hydrodense eosinophils. CONCLUSION: We conclude that the eosinophils of birch pollen allergic patients have reduced production of oxygen radicals when the patients are exposed to their allergen, which could depend on higher amounts of hypodense eosinophils in the blood during season.

Influence of allergen avoidance at high altitude on serum markers of eosinophil activation in children with allergic asthma.

A cohort of 12 asthmatic children was followed over several months, during which they moved back and forth from an allergen-free to an allergen-rich environment at high and low altitude, respectively. The children were treated with non-steroidal anti-asthmatic drugs as clinically needed. Histamine PC20-FEV1 was unaltered during the study period, whereas serum levels of eosinophil cationic protein (ECP) and eosinophil protein X (EPX) showed significant changes when the children were exposed to the offending allergens. The total IgE significantly increased during exposure. The serum levels of myeloperoxidase (MPO) as well as of chemotactic factors for both neutrophils and eosinophils were unaltered during allergen exposure. We conclude that the serum markers of eosinophil activity ECP and EPX are sensitive indices of allergen exposure in asthmatic atopic children.

Degranulation of eosinophils from pollen-atopic patients with asthma is increased during pollen season.

The secretion of granule proteins from eosinophils and neutrophils was studied in isolated cells, obtained from 11 pollen-atopic patients with asthma, twice during and twice outside pollen season. Granulocytes were stimulated with serum-opsonized Sephadex particles, and the released amount of eosinophil cationic protein (ECP), eosinophil protein X (EPX), and myeloperoxidase (MPO) were measured by means of specific radioimmunoassay (RIA). Eosinophils from the pollen-atopic patients obtained during pollen season released significantly more (p less than 0.02) ECP and EPX than cells from the same patients obtained before pollen season. The released amount of ECP and EPX was correlated (r = 0.54; p less than 0.003) to the total pollen count. The release of MPO from neutrophils was only raised (p less than 0.01) at the end of the pollen season. Serum concentrations of ECP and EPX and blood eosinophil counts were significantly raised (p less than 0.002, p less than 0.001, and p less than 0.009, respectively) before pollen season and increased further at the end of the pollen season. There were no changes in lung function during pollen season and consequently no discernible relationships to eosinophil and neutrophil degranulation. We conclude that eosinophils and, to some extent, neutrophils from birch pollen-atopic subjects have an increased propensity to secrete their granule proteins during a pollen season. We suggest that these cells have been primed as a consequence of allergen exposure.

The effect of immunotherapy on eosinophil accumulation and production of eosinophil chemotactic activity in the lung of subjects with asthma during natural pollen exposure.

Two groups of birch pollen--allergic patients with seasonal rhinoconjunctivitis and asthma were followed during two consecutive birch-pollen seasons, one group, N = 10, during a season with high pollen load, and one group, N = 15, during a season of low pollen load. Half the patients were treated with immunotherapy (IT) for 3 and 4 years, respectively. The other half of the patients served as control group (non-IT). Bronchoalveolar lavage (BAL) was performed once before each season and once during the pollen season. Eosinophil (EOS) numbers in BAL were increased (p less than 0.01) during the season with high pollen load but not in the season with a low pollen load, and this increment was absent in the IT-treated group. Also, the EOS cationic protein levels were raised in the non-IT-treated group during the season with a high pollen load. The levels of EOS and neutrophil chemotactic activity were raised in BAL in both seasons in the non-IT-treated group compared with the IT-treated group (p less than 0.02, p less than 0.003, p less than 0.04, and p less than 0.005 in high- and low-load pollen season, respectively). Serum and BAL eosinophil chemotactic activity (ECA) were positively correlated (p less than 0.001). We conclude that there is an influx of active EOSs into the lung of pollen-allergic patients with asthma during a pollen season, which may be abrogated by IT. Furthermore, the generation of ECA appears to be an extremely sensitive marker of antigenic exposure, and the potent inhibition of the generation of ECA by IT may provide a clue as to the mechanism of this treatment.

Eosinophils, secretory responsiveness and glucocorticoid-induced effects on the nasal mucosa during a weak pollen season.

This study examined the seasonal effects on eosinophils and secretory responsiveness of the nasal mucosa in 22 patients with allergic rhinitis due to birch pollen (11 patients received placebo and 11 budesonide, 200 micrograms once daily in each nostril). The pollen counts during the study season were too low to produce a significant symptomatology. Hence, our findings demonstrate threshold alterations of the airway mucosa in allergic rhinitis and their inhibition by anti-inflammatory drug intervention. The patients were monitored for 8 weeks with daily recordings of pollen counts and symptom scores. Once every week a series of laboratory tests was carried out: the local eosinophil influx was determined using a Rhinobrush technique; the levels of eosinophil cationic protein (ECP) were analysed in nasal lavage fluids; and the secretory response to intranasal methacholine was measured. Treatments started after a 2-week run-in period. The proportion of eosinophils increased markedly in the placebo group and was elevated also during the last two study weeks when the pollen counts were practically nil. The secretory responsiveness to methacholine increased during the pollen season and returned to baseline towards the end of the study period. The topical glucocorticoid treatment reduced the proportion of eosinophils, the ECP levels, and the secretory response to methacholine compared to placebo. We conclude that the increased traffic and activity of eosinophils and less conspicuously the increased secretory responsiveness are expressions of the mucosal inflammation that precede the development of symptoms in seasonal allergic rhinitis.

Immunotherapy abrogates the generation of eosinophil and neutrophil chemotactic activity during pollen season.

In a group of 40 birch pollen-allergic patients with a history of rhinoconjunctivitis and wheezing during the pollen season, 20 were immunotherapy (IT) treated preseasonally with birch-pollen extract (Pharmacia, Uppsala, Sweden). Blood samples for determination of the levels of heat-labile eosinophil chemotactic activity (HL-ECA), heat-labile neutrophil chemotactic activity (HL-NCA), and heat-stable neutrophil chemotactic activity were collected before the season, at the beginning of the study, at the start of the season, at the peak, at the end, and after the birch-pollen season. The symptoms from rhinoconjunctivitis and airways, peak expiratory flow, and use of medication were recorded throughout the season. Significant increases of HL-ECA and HL-NCA were observed in untreated compared with IT-treated patients at the start of the season (p less than 0.0001 for both activities) and at the peak of the birch-pollen season (p less than 0.0005 and p less than 0.01, respectively). At the end of the season, HL-ECA levels were not significantly different between the patient groups, whereas HL-NCA levels were still higher in untreated patients (p less than 0.005). We conclude that IT completely abrogates the generation of HL-ECA and HL-NCA during a pollen season.

Changes in non-specific nasal reactivity and eosinophil influx and activation after allergen challenge.

It has been suggested that the eosinophilic granulocyte plays a crucial role in the genesis of increased reactivity of the airways. In order to characterize changes in non-specific reactivity in the upper airways following a nasal allergen challenge further 16 subjects with strictly seasonal allergic rhinitis were studied. They were challenged with allergen outside the relevant pollen season and monitored at intervals for a period of 24 hr for nasal symptoms, changes in nasal reactivity, eosinophil influx and activation, and markers of inflammation. The same challenge sequence without an initial allergen challenge was used as a control. A symptom score technique was used to record nasal symptoms and methacholine challenges were used to monitor changes in non-specific reactivity. A nasal lavage was made prior to each methacholine challenge to monitor the influx of cells, specifically eosinophils, and to determine changes in the levels of eosinophil cationic protein (ECP) and TAME-esterase activity. Cells from the mucosal surface were also collected with a Rhinobrush prior to the allergen challenge as well as at the 24-hr follow up. The allergen challenge induced a five-fold increase in non-specific nasal reactivity, as measured by the methacholine challenges, at the 2-hr follow up from 0.051 ml +/- 0.012 (mean +/- s.e.m.) to 0.255 +/- 0.062 (P less than 0.01) and a significant increase was also noted at all observation points, whereas no increases could be observed in the control setting.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumin, bradykinins, and eosinophil cationic protein on the nasal mucosal surface in patients with hay fever during natural allergen exposure.

This study examined plasma- and eosinophil-derived products in nasal lavage fluids obtained from patients with hay fever during natural allergen exposure. Nine patients with strictly seasonal allergic rhinitis and five normal, nonallergic subjects (control group) were studied. Nasal lavages were performed twice weekly, starting 1 week before the expected birch-pollen season and continuing for 6 weeks, thereby covering the entire birch-pollen season. Nasal symptoms and pollen counts were recorded daily. The lavage fluid was analyzed for it content of albumin, bradykinins, and eosinophil cationic protein (ECP). During the pollen season, each of these solutes was significantly increased in the nasal lavage fluid from the allergic patients (p less than 0.05) but not from the control subjects. Albumin, bradykinins, and ECP generally correlated better between themselves than with symptoms and pollen counts. We conclude that natural exposure to allergens induces plasma exudation and increased levels of ECP on the human nasal mucosa.

Metal content of neutrophil granules is altered in chronic inflammation.

The mass fraction of certain elements was measured in isolated granulocytes and isolated granulocyte granule fractions from patients with active inflammatory arthritides (N = 6) and healthy controls (N = 6). The patients had significantly increased amounts of Ca in the granulocytes, in the specific and light azurophil granules, but normal Ca amounts in the dense azurophil granules. Sr was below the detection limit in the granulocytes and granule fraction from controls, but it appeared in high concentrations in the granulocytes and all granule fractions from the patients. The patients had considerably increased granulocyte amounts of Mn but only slightly increased Mn concentrations in the specific granules. Mn was not detectable in azurophil granules from patients and controls. A prominent accumulation of Fe was seen in the granulocytes from the patients, together with an Fe accumulation in the specific granules. Fe was below the detection limit in azurophil granules from patients and controls. The patients had reduced granulocyte Zn and reduced amounts of Zn in the dense and light azurophil granules but normal Zn amounts in the specific granules. The results obtained indicate that the granulocyte accumulation of Ca, Sr, and Fe observed during chronic inflammation is associated with corresponding granule accumulation of these metals; the considerable Mn accumulation in granulocytes during inflammation is not localized in their granules; and the granule subpopulations differ in their capacity to store certain metals.

The formation of eosinophil and neutrophil chemotactic activity during a pollen season and after allergen challenge.

Heat-stable (HS) and heat-labile (HL) neutrophil chemotactic activities (NCAs) have been demonstrated in serum after allergen challenge of subjects with asthma. In this investigation, we have studied the possible occurrence of similar activities in 20 atopic individuals on natural exposure to allergen, that is, during the birch-pollen season. Since eosinophil accumulation is a hallmark of an ongoing allergic inflammation in the respiratory tract also, the possible production of eosinophil chemotactic activity (ECA) was examined in serum after allergen challenge and at natural exposure to pollen. Both HL-NCA and HL-ECA were produced to a significant extent (p less than 0.001) during the season, with the peak of activities occurring simultaneously with the peak pollen count. HL-ECA was produced after allergen challenge of subjects with asthma in the laboratory, as has been demonstrated for NCA previously. The activity of the HS-NCA was unaltered during season. Gel-filtration studies of the major HL-NCA and HL-ECA indicated a molecular weight for both activities of 100 to 150,000, and the activities produced during season cochromatographed with the HL-NCA and HL-ECA produced after allergen challenge in the laboratory, suggesting that all these activities are due to one and the same molecule. The results suggest that the heat-labile chemotactic activity found in serum of atopic subjects and subjects with asthma after allergen exposure may be involved in the attraction of eosinophils and neutrophils to the site of allergic inflammation.

The effect of immunotherapy on bronchial hyperresponsiveness and eosinophil cationic protein in pollen-allergic patients.

The effect of immunotherapy (IT) on bronchial response to histamine and on eosinophil cationic protein (ECP) in 40 birch pollen-allergic patients with a history of rhinoconjunctivitis and wheezing during the birch season was examined. Twenty patients started IT with birch extract (Pharmacia, Uppsala, Sweden) before the season. The other 20 patients were not treated with IT. Histamine-challenge tests were performed before, at the start, at pollen peak, at the end, and after the birch-pollen season. Blood samples for determination of ECP were collected at the same time. Skin prick tests and nasal provocation tests were also performed before and after the season. A significant increase in bronchial hyperresponsiveness was noted in the group treated with IT and in the untreated group during the season. The increase was greatest in the untreated group with the maximal difference between the two groups at the end of the pollen season (p less than 0.07). IT treatment was followed by significantly less medication and higher peak expiratory flow values. The levels of ECP increased during the season in untreated patients (p less than 0.05) but not in patients treated with IT. The ECP levels of patients from both groups correlated significantly with histamine sensitivity (p less than 0.001).

Active participation of eosinophils in patch test reactions to inhalant allergens in patients with atopic dermatitis.

Intracutaneous testing and patch tests with house dust mite and grass pollen allergens were performed in patients with atopic dermatitis. Only patients with an immediate type skin reaction to house dust mite or grass pollen allergens showed a positive patch test reaction to these allergens 24-48 h after testing. Occasionally positive patch test reactions at 20 min, 2 h and 6 h were also observed. Patch test reactions were not found in normal controls or atopic patients without atopic dermatitis. Analysis of the cellular infiltrate demonstrated an influx of eosinophils into the dermis, starting from 2-6 h after patch testing. Immunostaining with antibodies against granular constituents of the eosinophils revealed that the infiltrating eosinophils were in an activated state and had lost part of their granular contents. At 24 h eosinophils also appeared in the epidermis. Electron microscopy showed that in the epidermis, some eosinophils were in close contact with Langerhans cells, suggesting a cell-cell interaction. Taken together, these results strongly suggest an active role for eosinophils in patch test reactions to inhalant allergens in atopic dermatitis patients.

Eosinophil chemotactic activity in allergic patients during the birch pollen season: the effect of immunotherapy.

Recently, heat-labile eosinophil chemotactic activity (ECA) has been found in serum after challenge of allergic asthmatic patients. In this study, we investigated changes in ECA in 40 birch-allergic patients during the birch pollen season; 20 of them had been treated with immunotherapy of birch pollen extract before the season. ECA raised significantly (p less than 0.001) in the untreated birch pollen-allergic patients during the season. Immunotherapy completely abolished this activity.

Eosinophil cationic protein in inflammatory synovial effusions as evidence of eosinophil involvement.

Eosinophils are seldom noted in inflammatory synovial fluids but are reported to infiltrate the synovial tissue in inflammatory arthritides. To elucidate a possible role for eosinophils in inflammatory joint reactions the concentrations of eosinophil cationic protein (ECP)--a specific granule protein from eosinophils--were measured by radioimmunoassay in 90 synovial fluids from patients with various inflammatory arthritides (rheumatoid arthritis, reactive and crystal arthritides, Reiter's disease and psoriatic arthropathy). In the same specimens lactoferrin was measured as an indicator of neutrophil-involved inflammation. In comparison with the normal circulating levels of ECP and lactoferrin the measured synovial fluid concentrations of both proteins were considerably raised in all patient groups with inflammatory joint diseases in contrast to patients with non-inflammatory arthritides. There was a striking positive correlation between the ECP and lactoferrin synovial fluid concentrations. These data indicate that eosinophil activation is prominent in inflammatory joint reactions and is linked to the activation of neutrophils. The regulation of degranulation or secretion by eosinophils is unknown. Our in-vitro studies showed that peripheral blood isolated neutrophils as well as eosinophils degranulated when exposed to IgG complexes. However, eosinophil degranulation was modest compared with neutrophil degranulation. These data suggest that neutrophil phagocytosis of, for example, immune complexes may be one major mechanism in neutrophil degranulation but that other factors determine the appearance of eosinophil products in inflammatory synovial effusions. The possible modulatory or harmful role of eosinophils in inflammatory joint disease can at present only be speculated on.