Complement Fixation Techniques Research Articles

Fatores de risco na transmissão e soroprevalência da infecção de Chlamydophila abortus a ovinos e caprinos

Resumo: O objetivo deste trabalho foi avaliar os fatores de risco envolvidos na transmissão de Chlamydophila abortus a ovinos e caprinos, bem como verificar a soroprevalência da infecção. Foram selecionadas 110 propriedades, com um total de 500 amostras de ovinos - 350 da Microrregião do Alto Médio Gurgueia (MRAMG) e 150 da Microrregião Homogênea de Teresina (MRHT), ambas do Estado do Piauí - e 600 amostras de caprinos - 300 da MRAMG e 300 da MRHT. Um questionário epidemiológico foi empregado para identificar os principais fatores de risco. Os anticorpos anti-C. abortus foram detectados pela técnica de fixação de complemento. A prevalência geral da infecção por C. abortus foi de 7,2% (79/1.100). A prevalência em caprinos e ovinos na MRAMG foi de 7,9% (51/650) e, na MRHT, foi de 6,2% (28/450). Nas microrregiões estudadas, a prevalência em ovinos foi de 8,2% (41/500) e, em caprinos, de 6,3% (38/600). O sistema de criação, as práticas reprodutivas e o tipo racial foram fatores de risco relevantes para a infecção em ovinos. Também foram relevantes em caprinos as práticas reprodutivas e a origem das matrizes e dos reprodutores. A raça Dorper apresenta maior suscetibilidade à infecção por C. abortus.

VIRUS ANTIBODY LEVELS IN SERUM SPECIMENS FROM PATIENTS WITH OPTIC NEURITIS AND FROM MATCHED CONTROLS

Virus antibody levels in serum specimens taken in acute and convalescent phases from 77 patients with optic neuritits were tested by measles hamagglutination inhibition (HI), measles hemolysis inhibition (HLI), rubella HI, parainfluenza-1 HI, Epstein-Barr immunofluorescence (IF), and against 11 other viruses and mycoplasma pneumoniae with the complement fixation (CF) technique. The virus antibody levels were indicated to be usually very stable, and a fourfold change in virus antibody levels was demonstrated in only eight patients. The virus antibody levels were compared with specimens from two carefully selected control groups. The first control group consisted of 71 healthy persons matched in age, sex and place of residence with the patients with optic neuritis. The other control group consisted of 58 patients with various neurological diseases other than multiple sclerosis (MS) or infectious diseases of the central nervous system. The patients with optic neuritis had significantly higher measles antibody titres than the two control groups in both measles HI and measles HLI tests. Also in 33 patients with optic neuritis of unknown cause, the measles antibody levels were higher than in the control groups. On the other hand, various other antibody tests showed no statistically significant differences between patients with optic neuritis and the control group.

A flow cytometry-based method for detecting antibody responses to murine cytomegalovirus infection

An assay based on target cells infected with green fluorescent protein labeled murine cytomegalovirus (GFP-MCMV) and dual color flow cytometry for detecting antibody to MCMV is described. After optimizing conditions for this technique, kinetics of anti-MCMV IgG antibody response was tested in susceptible (BALB/c) and resistant (C57BL/6) mouse strains following primary MCMV infection. Previously published antibody kinssetics were confirmed in susceptible mice, with peak IgG response seen ∼8 weeks after primary infection, decreasing by 20 weeks after infection. In contrast, MCMV resistant C57BL/6 mice showed significantly lower IgG antibody responses than susceptible mice. Although several techniques have been previously described to detect murine antibody responses to MCMV, including nuclear anti-complement immunofluorescence, viral immunoblotting, complement fixation, indirect immunofluorescence, indirect hemagglutination, and enzyme-liked immunosorbent assay techniques, these techniques are all time consuming and laborious. The technique presented is a simple time efficient alternative to detect previous MCMV antibody responses in experimentally infected mice.

Brucellosis—A Persistent Occupational Hazard in Ireland

A cross-sectional seroprevalence study using the complement fixation technique (CFT) was carried out among technical and support staff of the Department of Agriculture in Ireland (n=375). A result CFT of < 1:8 was accepted as normal, i.e., no evidence of exposure to Brucella abortus. Results were compared with available medical records to differentiate new from old or established cases. The participation rate was 75% (n= 281). Of the 281 participants, ten [3.6% (95% CI 1.7-6.5%)] tested positive (titers > or = 1:8). Veterinarians, laboratory staff, and workers based in meat plants were at increased risk of exposure. 106 previous results were available. Eight of those who tested positive had previously been tested, and of these, four (3.8%, 1-9.4%) had converted from negative to positive in the intervening five years, a conversion rate of 8 (CI 2-20) per 1,000 employees per annum. Thus, exposure to B. abortus remains common among at-risk occupational groups in Ireland.

Q fever in Ireland. A seroprevalence study of exposure to Coxiella burnettii among Department of Agriculture workers.

To estimate the risk of exposure to Coxiella burnettii among 'at risk' workers in Ireland. A cross-sectional seroprevalence study, using the complement fixation technique (CFT), was carried out among technical and support staff of the Department of Agriculture in Ireland (n = 375). Participants were divided into low- (n = 34), moderate- (n = 158) and high-risk (n = 83) groups according to the likelihood of occupational exposure. A result of <1:8 on CFT was accepted as normal, i.e. no evidence of past exposure to the causative organism, C. burnettii. Participants with titres of 1:16 were clinically assessed for evidence of past or present infection and interviewed regarding the possibility of non-occupational exposure. The participation rate was 75% (n = 281). Overall, 24 of the 281 participants (8.5%, 95% confidence interval = 5.6-12.4%) tested positive (titres = 1:8). No statistically significant difference existed between the three groups (low, 8.8%; moderate, 9.5%; high, 7.2%). Of those reviewed (n = 10), no evidence of either past or present clinically significant illness was detected. Possible non-occupational exposure was identified in two cases. Laboratory evidence of past exposure to Q fever is common amongst readily identifiable 'at risk' occupational groups in Ireland, and appropriate preventative steps are warranted. Employees who do not have direct exposure to animals or animal products, but who work in a high risk environment appear to have a similar risk of exposure C. burnettii. Although clinical illness appears to be rare, health care workers should consider the possibility of Q fever in cases of unexplained illness arising in those working in 'high risk' environments.

Autonomic nervous dysfunction in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA): possible pathogenic role of autoantibodies to autonomic nervous structures.

Autonomic nervous dysfunction has been previously reported in SLE, RA and systemic sclerosis, but the pathogenesis of such a complication is poorly understood. In the present study, four standard cardiovascular autonomic function tests were performed in 34 female patients with connective tissue diseases and in 25 healthy control subjects, and results expressed as cardiovascular (CV) test scores. Moreover, in each subject the presence of circulating complement-fixing autoantibodies directed against sympathetic and parasympathetic nervous structures, represented by superior cervical ganglia and vagus nerve, respectively, was simultaneously assessed by an indirect immunofluorescent complement-fixation technique, using rabbit tissue as substrate. None of the patients reported autonomic symptoms. However, an abnormal CV test score (> or = 5) was detected in 15% of the patients and in none of the healthy control subjects, approaching statistical significance (P = 0.07). No correlation was found between CV test results and disease duration, type of therapy or presence of conventional autoantibodies. One or two autoantibodies to autonomic nervous structures were detected in six patients (18%) and not in the control subjects (P < 0.05). Values of deep breathing test were significantly lower in autoantibody-positive patients compared with those amongst the control subjects (P < 0.05), and an abnormal CV test score was significantly associated with the presence of autoantibodies to autonomic nervous structures (P < 0.05). In conclusion, we confirm that autonomic nervous function can be impaired in patients with connective tissue diseases, and suggest that autoantibodies directed against autonomic nervous system structures may play a role in the pathogenesis of the autonomic dysfunction.

Autonomic function and autoantibodies to autonomic nervous structures, glutamic acid decarboxylase and islet tyrosine phosphatase in adolescent patients with IDDM

Recent studies have linked autoimmunity to nervous tissue structures and diabetic autonomic neuropathy, but data on the early stage of IDDM and on the natural history of this association are not available. For this reason, we investigated autonomic nervous function, and the presence of autoantibodies to sympathetic and parasympathetic nervous structures, to glutamic acid decarboxylase (GAD) and tyrosine phosphatase (IA-2/ICA512) in 85 adolescents with insulin-dependent diabetes mellitus (IDDM) (mean age 14.7±1.6 yr, mean duration of diabetes 6.8±3.5 yr), and 45 age and sex-matched healthy subjects. Nervous tissues autoantibodies were detected using an indirect immunofluorescent complement-fixation technique, with monkey adrenal gland, rabbit cervical ganglia and vagus nerve as substrates. GAD and IA-2/ICA512 autoantibodies were detected by radioimmunoprecipitation assay. Seven patients (8%) had anti-vagus nerve autoantibodies, 7 other patients (8%) had anti-cervical ganglia autoantibodies, while all controls were negative ( P<0.05). Anti-adrenal medulla antibodies were detected in 16 patients (19%) and in 2 control subjects ( P<0.02). None of the patients had autonomic symptoms. When patients were divided according to the presence or absence of autoantibodies, values of the cardiovascular tests (deep breathing, 30:15 ratio, Valsalva ratio) were similar in the two groups and similar to those in healthy subjects. However, when considered together, patients positive for one or more autoantibody showed a trend for lower values of deep breathing test and 30:15 ratio test, compared with healthy control subjects, which failed to reach conventional significance values ( P=0.17 and P=0.07, respectively). No correlation was found between cardiovascular parameters and metabolic control or diabetes duration. There was no association between autoimmunity to nervous tissue structures and presence of GAD and IA-2/ICA512 Ab, and no correlation between these two autoantibodies and values of cardiovascular tests. Our data indicate that autonomic dysfunction is not a characteristic of young diabetic patients, but that autoantibodies against autonomic nervous structures are present during the first 1 to 15 yr of diabetes. GAD and tyrosine phosphatase appear to be excluded as target autoantigens within autonomic structures. Follow-up studies are required to evaluate future autonomic dysfunction and symptoms in these patients, and to establish whether the subtle autonomic dysfunction detected and/or the nervous tissue autoantibodies, are predictive of the development of this complication.

Microbial inciters of acute asthma in urban Nigerian children.

In tropical Africa the role of microbial agents of acute respiratory infections in acute exacerbations of bronchial asthma remains largely unexplored. However, empirical antibacterial therapy is frequently initiated in moderate to severe cases of acute asthma with symptoms of acute respiratory infection. A study was set up to determine how often acute respiratory infection is associated with acute asthma, to identify the associated pathogens, and to proffer appropriate therapeutic suggestions. Over a 16 month period, 86 episodes of acute asthma were studied for clinical and laboratory features of acute respiratory infection at the University College Hospital (UCH), Ibadan. Virological diagnosis was based on immunofluorescence studies of nasopharyngeal aspirates and/or serological tests using the microtitre complement fixation technique. Throat swabs and blood were cultured for bacterial agents. Of the 64 cases who presented with rhinorrhoea, 51 (79.7%) were pyrexial (T > or = 37.6 degrees C). Inflammatory changes (frequently interstitial streakiness) were identified in 10 (19.6%) of the 51 chest radiographs; only two of these had lobar shadowing. Significant bacterial isolates were made in only three (3.5%) of the throat swabs and two (2.4%) of the blood cultures from the 86 cases; none had clinical septicaemia. On the other hand, 55 viral agents were identified from 39 (53%) of the 74 subjects studied; 16 (41.0%) had dual viral identifications. Respiratory syncytial virus (RSV) accounted for 20 (36.4%) identifications, parainfluenza virus (PIV) type 3 for 15 (27.3%), and influenza type A (Flu A) for 12 (21.8%). Viral identifications were significantly higher in infants and preschool subjects (< 5 years) and in those presenting with either rhinorrhoea or pyrexia. The results of this study underscore the importance of viral upper respiratory infections in asthma exacerbations in a tropical setting. The paucity of clinical and investigative features of bacterial acute respiratory infection suggests that there is little rationale for routine antibiotic cover in children with acute exacerbations of asthma in the tropics.

Mycoplasma pneumoniae and Chlamydia pneumoniae Strain TWAR Infections in U.S. Marine Corps Recruits

Paired sera from 208 healthy Marine Corps recruits undergoing 11 weeks of basic training in San Diego during 1989 were studied by complement fixation and microimmunofluorescence techniques for antibody to Mycoplasma pneumoniae and Chlamydia pneumoniae strain TWAR infections. Upon entering training, 52.7% and 64.4% of the recruits had evidence of prior infection with M. pneumoniae and C. pneumoniae, respectively. At the end of training, 5.9% of recruits had evidence of new infections with M. pneumoniae (4-fold antibody rise) and 3.8% had evidence for new infections with C. pneumoniae (4-fold antibody rise). Recruits with evidence of previous infection with C. pneumoniae had a lower relative odds of new infection during training with this agent (odds ratio = 0.07, 95% confidence interval 0.00-0.61). These data demonstrate that, like their counterparts in Scandinavia, U.S. military recruits also suffer from C. pneumoniae infections. Both M. pneumoniae and C. pneumoniae should be considered as potential causes of respiratory disease among U.S. military trainees.

Réaction de fixation du complément en plaques de microtitration : application à la sérologie de la myxomatose. Etude comparative des résultats avec la réaction d'immunofluorescence indirecte

The authors describe a complement fixation technique on microtitration plates, using an antigen prepared from myxomas induced in rabbits. Compared with indirect immunofluorescence this technique was less cumbersome, more economical, easier to read and (as a conventional procedure) applicable in all laboratories. Results obtained with 165 serum samples tested by both methods showed good correlation and a specificity at least equal to that of indirect immunofluorescence. Taking into account its lower sensitivity, the positive threshold value for complement fixation under the described experimental conditions was a dilution of 1:4 (H50).

Antibodies Specific for Human Albumin Function as Blocking Antibodies When Attached to Erythrocyte-Bound Albumin

Albumin is shown to be firmly bound to human red blood cells using the techniques of flow cytometry, immunoblotting, and complement fixation. The interactions between antibodies attached to the cell bound albumin and the complement system are examined. Antibodies specific for human serum albumin bind to albumin on erythrocytes and activate both homologous and heterologous complement in the absence of hemolysis. Moreover, treatment of erythrocytes with anti-albumin antibodies renders the cells resistant to classical pathway mediated lysis initiated by a passive lysis system. Thus, erythrocyte-bound anti-albumin antibodies appear to function in a manner similar to "blocking" antibodies described in some bactericidal systems.

Autoantibodies to nervous tissue structures are associated with autonomic neuropathy in type 1 (insulin-dependent) diabetes mellitus.

There is evidence that the immune system may play a role in the pathogenesis of autonomic neuropathy in Type 1 (insulin-dependent) diabetes mellitus. In the present study, we investigated the presence of autoantibodies to sympathetic and parasympathetic nervous structures and their correlation with other conventional autoantibodies in well-characterised diabetic populations, with or without diabetic neuropathy, and normal subjects. An indirect immunofluorescent complement-fixation technique was used, with monkey adrenal gland, rabbit cervical ganglia and vagus nerve as substrates. Of the patients with symptomatic autonomic neuropathy 33% were positive for at least one autoantibody (20% anti-sympathetic ganglia, 10% anti-vagus nerve and 13% anti-adrenal medulla). The frequency of having one or more antibodies to nervous tissues and the prevalence of anti-cervical ganglia antibodies were significantly higher in the neuropathic patients than in the diabetic control subjects with disease of similar duration and in the normal subjects (p < 0.05). Of the patients without complications with diabetes of shorter duration 33% were also positive for at least one autoantibody (13% anti-ganglia, 13% anti-vagus nerve and 13% anti-adrenal medulla). No correlation was found with other tissue autoantibodies, including islet cell antibodies. Our data indicate that nervous tissue autoantibodies are associated with symptomatic autonomic neuropathy. Anti-sympathetic ganglia and anti-vagus nerve antibodies seem to be more disease-specific. Patients with diabetes of shorter duration who were positive for these autoantibodies may represent pre-neuropathic patients.

A western blot assay detects autoantibodies to cryptic endothelial antigens in thrombotic microangiopathies

Autoantibodies detected by immunofluorescence, ELISA, and complement-fixation techniques have provided discriminatory markers for many human diseases. However, these commonly applied assays may fail to detect antibodies against antigenic sites which are either inaccessible or not displayed in recognizable cellular structures. Moreover, molecular identities of recognized antigen(s) are not determined with such methods. We have used Western blot analysis of cellular proteins derived from human renal microvascular endothelial cells (HRMEC) to identify autoantibodies in patients with pathological endothelial injury. Exploring the possibility that endothelial injury may expose cryptic endothelial antigens to immune recognition, we detected antibodies binding a number of distinct HRMEC proteins. Among these, antibodies recognizing specific HRMEC proteins of 43 kDa were commonly detected in plasmas from patients with thrombotic thrombocytopenic purpura (TTP) (13 of 14) and hemolytic uremic syndrome (HUS) (4 of 5) but were absent in 9 of 10 healthy subjects and 11 patients with a range of diseases not associated with endothelial injury or insult. Antibodies binding 43-kDa HRMEC antigens were detected in individual patients with systemic lupus erythematosus, anti-glomerular basement membrane nephropathy, and heparin-associated thrombocytopenia, as well as in one of three patients with immune thrombocytopenic purpura. Similar antibodies were detected in one hypercholesterolemic subject. Antibodies from four TTP patients were affinity purified and shown by two-dimensional analysis to recognize 43-kDa proteins having identical pl's (5.9, 6.0, and 6.1). Subcellular fractionation localized these antigens to cytosolic and nuclear compartments, sites presumably protected from immune recognition in the absence of endothelial injury.(ABSTRACT TRUNCATED AT 250 WORDS)

M4 and M9 Antibodies in the Overlap Syndrome of Primary Biliary Cirrhosis and Chronic Active Hepatitis: Epitopes or Epiphenomena?

Before the identification of the major mitochondrial antigens of primary biliary cirrhosis as components of the 2-oxo-acid dehydrogenase enzyme family, mitochondrial autoantigens were believed to be extremely heterogeneous and were divided into nine subtypes termed M1 to M9. This classification was based on the data derived from the relatively nonspecific biochemical and immunological techniques that were available. After the cloning and definition of the major autoantigens, more than 95% of the sera of patients with primary biliary cirrhosis were found to react with components of the 2-oxo-dehydrogenase enzymes; these enzymes correspond to the old M2 classification. Two other "M" species, dubbed M4 and M9, have attracted significant attention because they have been postulated to be prognostic indicators and more recently have been tentatively identified respectively as sulfite oxidase (EC 1.8.3.1) and glycogen phosphorylase (EC 2.4.1.1). Indeed, patients with the "overlap syndrome" are reported to have antibodies to M4 and a poor prognosis, whereas patients with antibodies to M9 have a favorable prognosis. To address the significance and definition of M4 and M9, we performed in-depth studies of sera from 11 patients with the overlap syndrome, 75 patients with primary biliary cirrhosis, 19 chronic active hepatitis patients, 13 patients with primary sclerosing cholangitis, 10 patients with cholangiocarcinoma, 20 patients with systemic lupus erythematosus, 20 patients with alcoholic cirrhosis, 17 patients with scleroderma and 30 normal individuals, using techniques of ELISA, complement fixation, immunoblotting and enzyme inhibition. We report herein that we were unable to show any disease-specific reactivity toward the proposed M4 and M9 antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

M4 and M9 antibodies in the overlap syndrome of primary biliary cirrhosis and chronic active hepatitis: Epitopes or epiphenomena?

Before the identification of the major mitochondrial antigens of primary biliary cirrhosis as components of the 2-oxo-acid dehydrogenase enzyme family, mitochondrial autoantigens were believed to be extremely heterogeneous and were divided into nine subtypes termed M1 to M9. This classification was based on the data derived from the relatively nonspecific biochemical and immunological techniques that were available. After the cloning and definition of the major autoantigens, more than 95% of the sera of patients with primary biliary cirrhosis were found to react with components of the 2-oxo-dehydrogenase enzymes; these enzymes correspond to the old M2 classification. Two other “M” species, dubbed M4 and M9, have attracted significant attention because they have been postulated to be prognostic indicators and more recently have been tentatively identified respectively as sulfite oxidase (EC 1.8.3.1) and glycogen phosphorylase (EC 2.4.1.1). Indeed, patients with the “overlap syndrome” are reported to have antibodies to M4 and a poor prognosis, whereas patients with antibodies to M9 have a favorable prognosis. To address the significance and definition of M4 and M9, we performed in-depth studies of sera from 11 patients with the overlap syndrome, 75 patients with primary biliary cirrhosis, 19 chronic active hepatitis patients, 13 patients with primary sclerosing cholangitis, 10 patients with cholangiocarcinoma, 20 patients with systemic lupus erythematosus, 20 patients with alcoholic cirrhosis, 17 patients with scleroderma and 30 normal individuals, using techniques of ELISA, complement fixation, immunoblotting and enzyme inhibition. We report herein that we were unable to show any disease-specific reactivity toward the proposed M4 and M9 antigens. We offer potential explanations for false-positive readings and, most importantly, propose that the “M” nomenclature be discontinued and that autoantigens be designated by their proven and reproducible biochemical identity. (HEPATOLOGY 1992;16:1128–1136.)

The sensitivity, specificity and efficiency values of some serological tests used in the diagnosis of paracoccidioidomycosis

This work reports on the results of double immunodiffusion (ID), counterimmunoelectrophoresis (CIE), complement fixation (CF) and indirect immunofluorescence (IIF) techniques in the serodiagnosis of paracoccidioidomycosis. The study was undertaken on four groups of individuals: 46 patients with untreated paracoccidioidomycosis, 22 patients with other deep mycoses, 30 with other infectious diseases (tuberculosis and cutaneous leishmaniasis) and 47 blood donors as negative controls. Data were obtained using Paracoccidioides brasiliensis antigens, i.e., a yeast culture filtrate for ID, CIE and CF, and a yeast cell suspension for IIF. The sensitivity, specificity and efficiency values were measured according to GALEN & GAMBINO. The gel precipitation tests (ID and CIE) showed the greatest sensitivity (91.3 and 95.6%, respectively), maximum specificity (100%) and the highest efficiency values when compared to the CF and IIF tests.

膠原病における帯状疱疹: I. 全身性エリテマトーデスおよびその免疫異常と帯状疱疹

We determined the incidence of herpes zoster (HZ) in 119 patients with systemic lupus erythematosus (SLE). HZ occurred in 56 patients (47%), and 9 patients had had HZ even before SLE developed. After diagnosis of SLE, an incidence of zoster was high, 5.45 cases per 100 person-years. It was found that the susceptibility to HZ was not related to the presence of renal disorder or maximum dose of corticosteroids. The patients with SLE who had had HZ showed significantly higher antibody titers than those without a history of HZ and normal subjects as assayed by both complement fixation technique and neutralization test. On the other had, only 17 of 55 patients (31%) with SLE showed positive skin reactions to varicella zoster virus (VZV) antigen, whereas all 15 normal subjects had positive reactions. In the patients who were receiving less than 10 mg/day of prednisolone, 11 of 17 (65%) had positive skin reactions to VZV antigen, whereas only 4 of 31 (13%) patients who were receiving 10 mg/day or more prednisolone showed positive reactions. It was of interest that in 7 patients with SLE who had not received corticosteroids, only 2 (29%) patients showed positive skin reactions to VZV antigen. These results suggest that high incidence of HZ in patients with SLE is probably due to an impaired cellular immunity because of both underlying disease and corticosteroid treatment.

膠原病における帯状疱疹

We investigated the incidence of herpes zoster (HZ) and the immunological state to HZ in patients with rheumatoid arthritis (RA) and mixed connective tissue disease (MCTD) in comparison with systemic lupus erythematosus (SLE). HZ occurred in 6 (25%) out of 24 patients with RA and 4 (22%) out of 18 patients with MCTD. One patient had had HZ before the diagnosis of RA. On the other hand, all 4 patients with MCTD had had HZ before the diagnosis of MCTD. The patients with RA and MCTD showed normal or higher antibody titers to varicella zoster virus (VZV) than normal subjects as assayed by both complement fixation technique and neutralization test. However, the antibody levels were not very high compared to those in patients with SLE. On the other hand, only 7 (50%) of 14 patients with RA and 4 (40%) of 10 patients with MCTD showed positive skin reactions to VZV antigen, whereas all 15 normal subjects had positive reactions. Thus, cellular immunity to VZV was thought to be impaired in these diseases. In the patients who were receiving less than 10 mg/day of prednisolone, 7 (64%) of 11 had positive skin reactions in RA patients and 3 (60%) out of 5 patients with MCTD, whereas none (0%) out of 3 patients with RA and 1 (20%) out of 5 patients with MCTD who were receiving 10 mg/day or more prednisolone showed positive skin reactions. These results suggest that the high incidence of HZ in patients with RA and MCTD is probably due to an impaired cellular immunity as in the case of SLE.

Rapid Diagnosis of Mycoplasma pneumoniae Infection: Clinical Evaluation of a Commercial Probe Test

A hybridization test for the diagnosis of Mycoplasma pneumoniae infection (Gen-Probe Rapid Diagnostic System) was evaluated using throat swabs and sputum samples from 160 army conscripts with acute infection of the lower respiratory tract. M. pneumoniae were cultivated from sputa, and Mycoplasma serology was done with paired sera by both complement fixation and enzyme immunoassay techniques. Comparison of the probe test results with the Mycoplasma culture and serologic results showed that the Gen-Probe test was sensitive and specific for the rapid diagnosis of acute M. pneumoniae infection of the lower respiratory tract when sputum was used: It had good sensitivity (0.95) and specificity (0.85) among patients whose serologic results were consistent with their culture results. In contrast, the probe test performed with throat swabs seemed to have only limited value.

Typage HLA classe II des leucémies myéloïdes chroniques par la réaction de fixation du complément sur lymphocytes stimulés par la phytohémagglutinine en présence d'Interleukine-2 et d'Interféron gamma

In 23 cases of chronic myelogenous leukemia (CML) in remission, HLA class II typing was performed by complement fixation technique on phytohemagglutin (PHA) activated lymphocytes. In 10 cases satisfactory results were obtained, whereas in 13 cases the cells were weakly or non reactive, making impossible a correct determination of HLA-DR,DQ specificities. In the 13 cases a conditioned medium containing Interleukin-2 (Il-2) and gamma interferon (IFN) was added to PHA, inducing a good HLA class II reactivity and making possible a satisfactory definition of HLA-DR,DQ specificities. The complement fixation technique on lymphocytes cultured with PHA, Il-2 and gamma IFN made possible a correct HLA-DR,DQ typing in 23 consecutive cases of CML, while such a typing is often difficult or impossible when using the microlymphocytotoxicity technique on B lymphocyte targets.