Obesity reduces the bioavailability of nitric oxide in juveniles.

OBJECTIVE: There is growing evidence that nitric oxide (NO) is critically involved in obesity and its clinical consequences like cardiovascular disease, hypertension and diabetes. We hypothesize that NO is already involved in the pathophysiology of juvenile obesity. We here determined the role of NO, its metabolites arginine and citrulline in obese and normal weight children. DESIGN: We investigated 57 obese and 57 normal weight age- and gender-matched juveniles. Various clinical parameters as well as body measurements and intima media thickness were determined. RESULTS: Obese juveniles revealed highly significant alterations in the NO pathway. NOX and citrulline were decreased in obese compared to normal weight juveniles and negatively correlated with body weight. Arginine was increased in obese juveniles and positively correlated with body weight. We found a significant negative correlation between NOX and oxidized low-density lipoprotein. Analysis of gamma-aminobutyric acid (GABA) revealed correlations with the NO pathway as NOX and citrulline were negatively correlated with GABA and arginine showed a positive correlation. CONCLUSION: We show here that NO and its metabolites arginine and citrulline are already involved in juvenile obesity that may contribute to atherogenesis via reduced bioavailability of NO. Moreover, we identify GABA as a new parameter in the mechanism of obesity-related NO reduction.

IgG antibodies against food antigens are correlated with inflammation and intima media thickness in obese juveniles.

OBJECTIVE: Systemic low grade inflammation may contribute to the development of obesity, insulin resistance, diabetes mellitus and atherosclerotic vascular disease. Food intolerance reflected by immunoglobulin G (IgG) antibodies may predispose to low grade inflammation and atherogenesis. We examined the relationship between IgG antibodies specific for food components, low grade inflammation and early atherosclerotic lesions in obese and normal weight juveniles. RESEARCH METHODS AND PROCEDURES: We determined IgG antibodies directed against food antigens, C-reactive protein (CRP) and the thickness of the intima media layer (IMT) of the carotid arteries in 30 obese children and in 30 normal weight children. RESULTS: Obese juveniles showed a highly significant increase in IMT (p=0.0001), elevated CRP values (p=0.0001) and anti-food IgG antibody concentrations (p=0.0001) compared to normal weight juveniles. Anti-food IgG showed tight correlations with CRP (p=0.001/r=0.546) and IMT (p=0.0001/r=0.513) and sustained highly significant in a multiple regression model. DISCUSSION: We show here, that obese children have significantly higher IgG antibody values directed against food antigens than normal weight children. Anti- food IgG antibodies are tightly associated with low grade systemic inflammation and with the IMT of the common carotid arteries. These findings raise the possibility, that anti-food IgG is pathogenetically involved in the development of obesity and atherosclerosis.

Increased neopterin in patients with chronic and acute coronary syndromes.

OBJECTIVES: The aim of our study was to determine neopterin levels in patients with chronic and acute coronary syndromes. BACKGROUND: In chronic and acute coronary syndromes the release of different cytokines activates cellular defense. Infiltration of neutrophils and monocytes/macrophages is detected in the vessel wall as well as in the myocardium. Neopterin, which is a by-product of the guanosine triphosphate-biopterin pathway, is a marker for those activated macrophages. METHODS: We studied 123 subjects: 1) 21 consecutive patients (17 men, 4 women; mean age +/- SD 66 +/- 15 years, range 31 to 87) with acute myocardial infarction (AMI); 2) 62 consecutive patients (50 men, 12 women; mean age 61 +/- 8 years, range 43 to 81) with signs and symptoms of clinically stable coronary artery disease (CAD); and 3) 40 healthy blood donors (28 men, 12 women; mean age 35 +/- 13 years). Neopterin levels were determined with a commercially available enzyme-linked immunosorbent assay method. RESULTS: In patients with AMI before thrombolytic therapy, neopterin levels were significantly higher than levels in patients with CAD and control subjects (13.7 vs. 8.6 and vs. 6.8 nmol/liter, p < 0.0001). Values also differed significantly between patients with CAD and control subjects (p < 0.0001). Neopterin levels in patients with AMI were measured seven times during a 72-h period. Within-group comparison showed significant differences over this period (p < 0.00001). The lowest value (11.4 nmol/liter) was observed after 4 h and differed significantly from the initial value and values after 24 and 72 h (p < 0.05). After 72 h, neopterin increased to 14.9 nmol/liter, a value significantly different from all values other than the initial one. There was no correlation between neopterin and creatine kinase (CK); CK, MB isoenzyme; or lactate dehydrogenase as markers for the extent of the myocardial infarction during the observation period. CONCLUSIONS: Our data support the hypothesis of an activation of monocytes and macrophages in patients with an acute or chronic coronary syndrome. Neopterin as a marker for macrophage activation is significantly increased in patients with chronic CAD and more pronounced in patients with AMI shortly after the onset of symptoms.

Iodine deficiency induces thyroid autoimmune reactivity in Wistar rats.

The last 2 decades it has become clear that iodine deficiency has a modulating effect on the thyroid autoimmune response in humans. Also, in animals that spontaneously develop autoimmune thyroid disease, evidence is accumulating that a low iodine intake can modulate thyroid autoimmune reactivity. However, it is still not clear what the effect of a low iodine intake on thyroid autoimmune reactivity is in normal nonautoimmune animals. To study the relationship of a dietary low iodine intake on the thyroid autoimmune reactivity in nonautoimmune animals, normal Wistar rats (female) were kept on an enriched iodine diet (daily iodine intake of 100 micrograms iodine), a "for our area normal" (conventional) diet (COD; daily iodine intake of 7 micrograms iodine), a low iodine diet (LID; 2 days of 1% KCLO4, followed by iodine-deficient drinking water/pellets), or an extremely low iodine diet (LID+; 1% KCLO4 continuously in the drinking water and iodine-deficient pellets). The enriched iodine diet rats were euthyroid (T3, approximately 8 nM/liter: T4, approximately 50 nM/liter; TSH, approximately 2 ng/ml), had a normal thyroid weight (approximately 12.5 mg), and showed only minimal signs of local thyroid immune reactivity; low numbers of intrathyroidal dendritic cells (DC; approximately 35 DC/mm2), CD4+ cells (approximately 2 cells/mm2), and CD8+ cells (approximately 2.5 cells/mm2) were found in combination with low anticolloid antibody production (incidence of positive animals, 12.5%). The COD resulted in a normal thyroid function. The rats were euthyroid (range of T3, 1.6-1.2 nM/liter; T4, approximately 50 nM/liter; TSH, approximately 2 ng/ml) and had a normal thyroid weight (approximately 12.5 mg). However, some signs of thyroid autoimmune reactivity were found [number of intrathyroidal DC, approximately 40/mm2; approximately 3 CD4-positive (CD+) cells/mm2; approximately 3 CD8+ cells/mm2; together with a 30% incidence of anticolloid antibodies]. The LID and LID+ not only induced goiter formation [thyroid weight, 27.3 +/- 4.2 mg (mean +/- SD) after 12 weeks of LID and 38.4 +/- 5.3 mg after 4 weeks of LID+] and low production of T4 by the thyroid [28 +/- 3 nM/liter (mean +/- SD)] after 12 weeks of LID and 14 +/- 3 nM/liter after 2 weeks of LID+], but also induced various signs of thyroid autoimmune reactivity.(ABSTRACT TRUNCATED AT 400 WORDS)

Chromatographically purified immunoglobulin G of endemic and sporadic goiter patients stimulates FRTL5 cell growth in a mitotic arrest assay.

A strain of differentiated rat thyroid cells (FRTL5) in continuous culture was used to study the presence of thyroid growth-promoting immunoglobulins (TGI) in the serum of patients with endemic and sporadic euthyroid goiters. To identify true in vitro cell proliferation a microscopic mitotic arrest assay was used. Immunoglobulins G (IgGs) were prepared with QAE-Sephadex A-50 or protein-A-Sepharose. A positive growth stimulation index was found in IgG preparations of 65 of 71 patients with endemic goiter and in 9 of 14 IgG preparations of patients with sporadic goiter. IgG preparations of 15 control subjects from an area where endemic goiter due to iodine deficiency does not occur and of 18 subjects without iodine deficiency and without thyroid enlargement living in the endemic area did not stimulate FRTL5 cell growth. FRTL5 cell growth stimulation with IgGs of these euthyroid goiter patients could only be detected when IgG was tested in combination with a small dose of TSH. Immunoprecipitation with polyclonal and monoclonal antihuman IgG was able to abolish the growth-promoting effects. In 32 blinded samples the Feulgen cytobiochemical assay, formerly used to detect TGI, was compared with the FRTL5 mitotic arrest assay. The two methods showed similar results. Our observations of chromatographically purified IgG promoting thyroid cell proliferation in vitro provide good evidence that IgG was responsible for thyroid cell growth in vitro and suggest that autoimmune growth mechanisms may be involved in the pathogenesis of both endemic and sporadic goiters.

Daily oral magnesium supplementation suppresses bone turnover in young adult males.

This study examined the effects of daily oral magnesium (Mg) supplementation on bone turnover in 12 young (27-36 yr old) healthy men. Twelve healthy men of matching age, height, and weight were recruited as the control group. The study group received orally 15 mmol Mg (Magnosolv powder, Asta Medica) daily in the early afternoon with 2-h fasting before and after Mg intake. Fasting blood and second void urine samples were collected in the early morning on days 0, 1, 5, 10, 20, and 30, respectively. Total and ionized Mg2+ and calcium (Ca2+), and intact PTH (iPTH) levels were determined in blood samples. Serum biochemical markers of bone formation (i.e. C-terminus of type I procollagen peptide and osteocalcin) and resorption (i.e. type I collagen telopeptide) and urinary Mg level adjusted for creatinine were measured. In these young males, 30 consecutive days of oral Mg supplementation had no significant effect on total circulating Mg level, but caused a significant reduction in the serum ionized Mg+ level after 5 days of intake. The Mg supplementation also significantly reduced the serum iPTH level, which did not appear to be related to changes in serum Ca2+ because the Mg intake had no significant effect on serum levels of either total or ionized Ca2+. There was a strong positive correlation between serum iPTH and ionized Mg2+ (r = 0.699; P < 0.001), supporting the contention that decreased serum iPTH may be associated with the reduction in serum ionized Mg2+. Mg supplementation also reduced levels of both serum bone formation and resorption biochemical markers after 1-5 days, consistent with the premise that Mg supplementation may have a suppressive effect on bone turnover rate. Covariance analyses revealed that serum bone formation markers correlated negatively with ionized Mg2+ (r = -0.274 for type I procollagen peptide and -0.315 for osteocalcin), but not with iPTH or ionized Ca2+. Thus, the suppressive effect on bone formation may be mediated by the reduction in serum ionized Mg2+ level (and not iPTH or ionized Ca2+). In summary, this study has demonstrated for the first time that oral Mg supplementation in normal young adults caused reductions in serum levels of iPTH, ionized Mg2+, and biochemical markers of bone turnover. In conclusion, oral Mg supplementation may suppress bone turnover in young adults. Because increased bone turnover has been implicated as a significant etiological factor for bone loss, these findings raise the interesting possibility that oral Mg supplementation may have beneficial effects in reducing bone loss associated with high bone turnover, such as age-related osteoporosis.

Cytomegalovirus diagnosis in renal and bone marrow transplant recipients: the impact of molecular assays.

BACKGROUND: Cytomegalovirus (CMV) infections are a major threat in transplant recipients. In recent years, new assays for routine CMV diagnosis, based on molecular techniques, have become available. OBJECTIVE: The impact of molecular assays for CMV diagnosis in transplant recipient was evaluated. STUDY DESIGN: A total of 51 transplant recipients were screened for CMV infection. Serological (AxSYM CMV IgG and recombinant CMV IgM assays), antigenemia, CMV DNA (qualitative in house PCR and the quantitative COBAS AMPLICOR CMV MONITOR Test), and CMV mRNA (NucliSens CMV pp67 Test) tests were compared. RESULTS: In 11/20 bone marrow transplant (BMT) recipients and 10/31 renal transplant (RTX) recipients there was no evidence of active CMV infection. Ten RTX recipients and one BMT recipient were antigenemia positive, 21 RTX and seven BMT recipients were PCR positive (qualitative CMV PCR). There were more BMT recipients CMV DNA positive in serum (7/21) than antigenemia positive (1/21). CMV mRNA was found positive in two BMT recipients (one case with no other evidence of CMV infection, the other one CMV DNA positive and antigenemia negative). The only antigenemia positive BMT recipient was found negative for CMV mRNA, but positive in all other tests. Eight RTX recipients were found positive for CMV mRNA. Six of them were also antigenemia positive and five of those were also found positive for CMV IgM. One CMV mRNA positive RTX recipient was CMV IgM positive but antigenemia negative and the other one CMV mRNA positive RTX recipient was found negative in all other tests. Two antigenemia positive RTX recipients were found negative for mRNA and CMV IgM. CONCLUSION: Antigenemia was found to be a good screening test for CMV infection in RTX recipients. In BMT recipients, tests based on molecular techniques appeared to be superior compared to antigenemia.

Monitoring of cytomegalovirus disease after heart transplantation: persistence of anti-cytomegalovirus IgM antibodies.

During the first year after orthotopic heart transplantation 39 recipients (given prophylactic immunosuppression with antithymocyte globulin for 7 days after orthotopic heart transplantation and triple drug maintenance therapy) were screened for cytomegalovirus antigenemia and anti-cytomegalovirus immunoglobulin M (index) and immunoglobulin G levels (antibody units) by MEIA-method. Until day 14, all recipients received cytomegalovirus hyperimmunoglobulin at a dosage of 2 ml/kg/day. Four patient groups were defined: group 1 (n = 15) seropositive recipient/seropositive donor, group 2 (n = 9) seronegative recipient/seropositive donor, group 3 (n = 8) seropositive recipient/seronegative donor and group 4 (n = 7) seronegative recipient/seronegative donor. Twenty-four donors and 23 recipients were seropositive for anti-cytomegalovirus immunoglobulin G. After transplantation, 31 recipients tested positive for cytomegalovirus antigenemia before immunoglobulin M elevation and at least 7 days before the onset of clinical symptoms of cytomegalovirus. In group 2, episodes of cytomegalovirus antigenemia appeared earlier, were more frequent, and lasted longer than in groups 1 and 3. Without previous evidence of positive cytomegalovirus antigenemia testing, no sign of cytomegalovirus disease was seen. When cytomegalovirus antigenemia was positive, cytomegalovirus hyperimmunoglobulin was readministered at the same dosage and gancyclovir (1000 mg/day) was given until cytomegalovirus antigenemia disappeared. However, episodes of recurrent cytomegalovirus were observed (2.6 +/- 1.9, 4.3 +/- 1.0, and 2.3 +/- 1.2 in groups 1, 2 and 3, respectively). In groups 1 and 3, the anti-cytomegalovirus immunoglobulin G antibody level remained high during the observation period. In groups 2 and 4 anti-cytomegalovirus immunoglobulin G antibodies were positive because of hyperimmunoglobulin prophylaxis but immunoglobulin G decreased again after discontinuation of the prophylaxis.(ABSTRACT TRUNCATED AT 250 WORDS)

Troponin T as a marker for posttransplantation adaptational problems of the donor heart.

BACKGROUND: Troponin T is used as a marker for myocardial cell damage (e.g., in aiding diagnosis and follow-up of myocardial infarction). Elevated troponin T levels are also observed after heart transplantation, although until now no explanation could be found for this phenomenon. METHODS AND RESULTS: Serum samples of 15 patients who underwent orthotopic heart transplantation were tested for troponin T with a one-step enzyme immunoassay. The highest concentrations of troponin T were seen between day 3 and 14 after transplantation (3.05 +/- 1.30 micrograms/L) and remained elevated up to 3 months. A correlation (r = 0.61, p < 0.02) was found between pretransplantation systolic pulmonary artery pressure and the cumulative troponin T release after transplantation. No association was found with rejection, and no correlation was found with ischemic time of the donor heart. CONDITIONS: These findings support the hypothesis that the acute exposure of the donor heart to the preexisting elevated right ventricular afterload in the recipient represents a strong mechanical stress for the transplanted heart. Measurement of troponin T may therefore be helpful in the posttransplantation monitoring and management of ventricular function after orthotopic heart transplantation.

A phase I/II study of 4'-O-tetrahydropyranyl-doxorubicin, 5-fluorouracil, and high-dose leucovorin as first-line therapy in advanced breast cancer patients.

A total of 50 patients were treated weekly with 5-fluorouracil (FU), leucovorin (LV), and 4'-O-tetrahydropyranyl-doxorubicin (THP) as first-line chemotherapy for advanced breast cancer (ABC). In phase I the doses of LV (500 mg/m2, day 1) and FU (350 mg/m2, day 1) were held constant, while the dose of THP (day 1) was escalated, from the initial dose of 10 mg/m2 up to the maximum tolerated dose (MTD). Twenty-eight patients entered phase I, and MTD for THP was defined as 35 mg/m2 in this combination. Dose-limiting toxicities were myelosuppression and hepatotoxicity. In phase II, another 22 patients were treated with THP at a dose level of 30 mg/m2. Including 4 patients already treated at this dose in the first part, 25 patients were evaluable for response: 1 patient obtained a complete response (CR) and 13 showed a partial response (PR), giving an objective response rate of 56%. The median duration of response was 9.1+ months and median survival, 15.5+ months. Side effects were generally mild, with ECOG grade I and II leukopenia in 51% of all cycles and grade III in 3% of the courses. Other toxicity included nausea and vomiting (54% and 8%, respectively) and alopecia (24%), all restricted to ECOG grade I and II. Our results suggest that weekly THP/LV-FU represents an active regimen for first-line treatment of ABC with relative low toxicity.

Weekly 5-fluorouracil and high-dose folinic acid in combination with epidoxorubicin as first-line therapy in advanced breast cancer: a phase II study.

A total of 25 patients with advanced breast cancer were treated weekly with i.v. 5-fluorouracil at 350 mg/m2, folinic acid at 500 mg/m2, and epidoxorubicin at 35 mg/m2 as first-line chemotherapy for a maximum of 18 cycles. In all, 24 patients were evaluable for response. Overall, 1 patient achieved a complete response and 11 patients showed a partial response, for an objective response rate of 50%; the median duration of response was 18.3+ months and median survival amounted to 18.8+ months. Side effects were generally mild, with grade II leukopenia occurring in 10 patients and grade III leukopenia, in 1 patient. Other toxicity included nausea and vomiting (82%), diarrhea (48%), stomatitis (48%), and alopecia (92%), all of which were mainly restricted to WHO grades I and II. Our results suggest that leucovorin modulation of 5-fluorouracil can safely be incorporated into combination chemotherapy with epidoxorubicin on the investigated schedule. The observed response rate appears comparable with that obtained with other first-line regimens.

[Breast cancer in the man: a report of 30 patients]. / Das Mammakarzinom des Mannes: Ein Bericht über 30 Patienten.

A retrospective review of male patients suffering from breast cancer seen over an 18-year period was carried out at the Department of Clinical Oncology of the University Hospital of Graz. Thirty evaluable cases were analysed. Eight patients had Stage I, 11 had Stage II, 8 had Stage III, and 3 had Stage IV disease. Local control was achieved in the majority, 29/30 (97%), by either surgery alone or combined surgery and radiation therapy. Local recurrence developed in 2 (7%) patients. Further 7 (23%) patients developed distant metastases and were treated in accordance with policies developed for the appropriate stage of the disease in females, with hormonal manipulation for hormone receptor-positive and -unknown patients and chemotherapy for hormone receptor-negative patients. The corrected five-year survival (Kaplan-Meier) is 83% for the entire group, 100% for patients with Stage I disease, 86% in Stage II, and 67% in Stage III and IV disease, respectively. This corresponds well with the results in recently published series. Stage of disease at initial presentation was a significant factor determining survival in our investigation. Our own data as well as recent data from literature suggest that with respect to TNM Stages in mammary carcinoma, there is no prognostic difference between men and women. To what extent improved local control by adequate local therapy or systemic adjuvant treatment modalities may improve overall survival remains to be discussed.

[Allergic bronchial asthma caused by bromelin]. / Allergisches Asthma bronchiale durch Bromelin.

The proteolytic enzymes of Bromeliaceae (bromelin) are commonly used in pharmaceutical industries, food production and diagnostic laboratories. We report two cases of occupational allergy to bromelin with predominantly respiratory manifestation (allergic bronchial asthma). Obviously sensitisation to bromelin usually takes place due to inhalation and not due to ingestion.

Asthma caused by bromelain: an occupational allergy.

Bromelains consist of a group of proteolytic enzymes of Bromeliaceae. They are commonly used in pharmaceutical industries, food production and in diagnostic laboratories. Bromelains are known to cause IgE-mediated reactions of both the immediate type and the 'late phase reaction of immediate type reaction' with predominantly respiratory symptoms. We report four cases of occupational allergy to bromelain in workers of a blood grouping laboratory. These observations prompted us to investigate the sensitization rate to bromelain in all workers of the particular diagnostic laboratory who had contact with bromelain. These results were compared with those obtained from healthy, randomly selected individuals without evident bromelain exposure. Our findings indicate that (i) bromelain is a strong sensitizer, (ii) sensitization usually occurs due to inhalation and not to ingestion, (iii) bromelain allergy is occupationally acquired, and adequate precautions are necessary. We can further state that (iv) skin testing with relatively pure allergens such as isolated proteases like bromelain may induce systemic reactions, even at very high dilutions.

Thyroid growth stimulating immunoglobulins in sporadic and endemic colloid goitre.

Several methods have been described to measure immunoglobulins stimulating the growth of thyroid cells in vitro, the so called Thyroid Growth stimulating Immunoglobulins (TGI). The methods make use of either Ig-stimulated guinea pig thyroid (organ) cultures (the cytochemical bioassays; growth is measured via Feulgen-densitometry or pentose shunt analysis), the culture of Ig-stimulated rat or porcine thyroid follicles (growth is measured via 3H-thymidine incorporation), or of Ig-stimulated rat FRTL-5 cells (growth is measured via 3H-thymidine incorporation, or counting the number of mitoses in arrest). The various methods have now been validated: (a) the data obtained with TGI preparations in the Feulgen Cytochemical Bioassay (CBA's) correlate well with those obtained in the FRTL-5 mitosis arrest assay with the same TGI preparations, (b) the growth stimulation can not be ascribed to hormonal contaminations of the used Ig preparations, since protein A-sepharose purified IgG is active in the assays and since anti human IgG's neutralize the growth stimulating effects of the preparations. Using the assays TGI has been found positive in goitrous Graves patients, in sporadic goitre patients and in endemic goitre patients. Particularly, patients complaning of recurrent goitre after thyroidectomy or with recent goitre growth are TGI positive. TGI occurs in sporadic goitre in the absence of TSH-receptor antibodies. The autoimmune-prone animal model of the BB rat also proved to be TGI-positive; the animal shows an increased thyroid glandular weight. Both the histomorphology of human goitres as well as the goitre of the BB rat indicate that the dendritic cell plays a prominent role in initiating the thyroid autoimmune reaction.

[Suppression of lymphocyte function 2 years following surgical treatment of paranasal sinus mycosis]. / Suppression der Lymphozytenfunktion zwei Jahre nach operativer Behandlung einer Nebenhöhlenmykose.

Prior investigations showed that acutely diseased patients with an aspergillus sinusitis manifested immune dysfunctions in respect of both T and B lymphocytes. In contrast to patients with nonmycotic sinusitis reduced in vitro and in vivo responsiveness was observed. The aim of this study, carried out after removal of the fungus ball and endoscopic surgery in clinically healthy patients, was to ascertain whether this reduced responsiveness was to be regarded as the effect or cause of an Aspergillus fumigatus infection. Two years later, the in vivo response to recall antigens was normal in both groups of patients, whereas the response to mitogens (ConA, PHA and PWM) was still decreased in the aspergillus sinusitis groups. The data suggest that the reduced immune response is a consequence of the Aspergillus fumigatus infection. Depressed skin reactivity is only present during acute infection, while proliferative capacity, as measured in the "whole blood stimulation" assay is depressed for a long time after healing the acute infection.

Testing for human immunodeficiency virus (HIV-1) antigens in haemophiliacs positive for HIV antibody.

Sera collected from 28 haemophiliacs during the 2 years from 1985 to 1987 were examined for the presence of human immunodeficiency virus (HIV-1) antigen by two different methods using commercially available test kits. Of 28 patients, 18 had been positive for HIV antibody since at least 1985 and their HIV infection by blood products went back 3-6 years. Of these 18 antibody-positive patients, 8 were positive for HIV antigen according to one or both antigen tests on one or more occasions. The longest period of antigen expression was 21 months in two patients, one being in perfect health, the other showing AIDS-related complex (ARC) for the last 9 months. The detection of antigen expression was highly variable between the two tests used. Both positive and negative antigen-test results must therefore be used with great caution in clinical practice.

Immunoquantification of lipoprotein(a): comparison of nephelometry with electroimmunodiffusion.

A new fully automated nephelometric immunoassay for lipoprotein(a) quantification in human serum was evaluated using the Behring Nephelometer Analyzer. The assay exhibited a good linearity in the concentration range of 110-1,770 mg/l; at higher concentrations, samples were automatically diluted by a factor of 4. The method is simple, robust, and shows an excellent stability of the calibration curve over several weeks. Intra-assay and day-to-day coefficients of variation were 2% and 4.5%, respectively. The method correlated well with electroimmunodiffusion (r = 0.977; n = 123; P = 0.0001). Unspecific turbidity as expressed by an elevated blank value occurred in 3% of all freshly measured samples (n = 392). Storage of the samples for 1 week at 4 degrees C had no significant influence on the results. Frozen sera, on the other hand, cannot be assayed by this method. We believe that this assay is well suited for use in clinical routine work.

In vivo and in vitro suppression of lymphocyte function in Aspergillus sinusitis.

In about 10% of patients who are operated on for chronic sinusitis, an aspergilloma is found in the affected paranasal sinus. In order to detect possible underlying immune defects, 25 patients with aspergillomas were subjected to an immunological screening program. The data obtained were compared with those of patients with non-mycotic chronic sinusitis and healthy controls. Total lymphocyte counts and immunoglobulin levels were normal in both groups with sinusitis. However, leukocyte subset analyses using membrane fluorescence revealed a significant decrease of CD11+ cells (macrophages, monocytes and natural killer-cells) in both types of sinusitis. Furthermore, a markedly enhanced frequency of CD25+ cells (interleukin 2-receptor-bearing cells), was observed in patients with the aspergillomas. Additionally, peripheral blood lymphocytes in both groups of patients showed a significant reduction in the proliferative response to both T- and B-cell mitogens, with the values for the mitogens ConA and PHA being significantly lower in the aspergilloma patients as compared to those with non-mycotic sinusitis. This lack of lymphocyte stimulation in the aspergilloma group was also manifest in skin tests to recall antigens. These first data suggest that there is an immune deficiency in patients with chronic sinusitis caused by Aspergillus fumigatus. Further studies are needed to clarify if this defect is the cause or the result of the mycotic infection.