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PubMed1993

Report on the Fifth International Society of Blood Transfusion Platelet Serology Workshop.

The Fifth International Society of Blood Transfusion (ISBT) Platelet Serology Workshop took place in 1990. A total of 21 laboratories participated in the wet workshop. Results were discussed at a meeting of the International Committee on Standardization in Haematology (ICSH) Expert Panel on Platelet Serology at the Joint Congress of the ISBT and the American Association of Blood Banks in Los Angeles in November 1990. Each of the participants analyzed 37 serum samples for platelet-reactive alloantibodies and isoantibodies. In addition, two drug-dependent (quinine) platelet-specific antibodies had to be identified among a subset of seven sera. For the first time in a platelet serology workshop, five platelet suspensions had to be typed for the alloantigens of the HPA-1, -3, -4, and -5 systems.

Antibodies↗

PubMed1993

Absence of hepatitis B virus DNA detected by polymerase chain reaction in blood donors who are hepatitis B surface antigen negative and antibody to hepatitis B core antigen positive from a United States population with a low prevalence of hepatitis B serologic markers.

A recent study in hepatitis B surface antigen (HBsAg)-negative, antibody to hepatitis B core antigen (anti-HBc)-positive blood donors from a population with a high prevalence of hepatitis B serologic markers showed the presence of hepatitis B virus DNA (HBV DNA) as detected by polymerase chain reaction (PCR) in 4 percent of these donors. A sensitive, nested PCR assay was used to assess the prevalence of HBV DNA in a population of HBsAg-negative, anti-HBc-positive blood donors from a United States population with a low prevalence of hepatitis B serologic markers. The lower limit for detection by the PCR assay was 10(-5) pg per mL of HBV DNA. There was a review of 26,492 consecutive blood donations in a 12-month period. During this time, only 1 unit (0.004%) was HBsAg positive. An additional 158 units (0.6%) were repeatably reactive for anti-HBc. These 158 HBsAg-negative, anti-HBc-positive units were given by 119 donors of blood for allogeneic and autologous use. HBV DNA was not detected by PCR in blood from 83 allogeneic blood donors (93 samples) or 36 autologous blood donors (65 samples). Anti-HBc testing is an inefficient means of screening for potential hepatitis B infectivity and is associated with low test specificity in populations with a low prevalence of hepatitis B serologic markers.

Adolescent↗

PubMed1994

Detection of human immunodeficiency virus type 1 p24 antigen and plasma RNA: relevance to indeterminate serologic tests.

BACKGROUND: Most enzyme immunoassay-reactive specimens producing indeterminate Western blot results belong to individuals who are not infected with human immunodeficiency virus type 1 (HIV-1). However, a small percentage may correspond to early seroconversion or advanced disease, at which stage partial reactivity on Western blot may be observed. STUDY DESIGN AND METHODS: To determine the utility of HIV-1 p24 antigen and cell-free RNA detection for the resolution of Western blot-indeterminate serologic results, several types of enzyme immunoassay-positive, sero-indeterminate specimens were analyzed. Samples were obtained from infected individuals at the time of seroconversion (n = 20), from patients with AIDS (n = 2), as specimens from clinical samples obtained for diagnostic testing (n = 57), from blood donors producing persistent indeterminate results (n = 47), and from random blood donors (n = 72). RESULTS: HIV-1 p24 antigen was detected in 10 of 20 specimens collected from 9 of 12 individuals who seroconverted and in 2 of 2 AIDS patients. HIV-1 plasma RNA was positive in 22 of 22 samples from those 14 individuals. All of 57 diagnostic specimens and 47 samples obtained from persistently indeterminate donors were negative for HIV-1 p24 antigen and plasma HIV-1 RNA. One of 72 blood donor specimens was positive for HIV-1 plasma RNA and had borderline reactivity for p24 antigen. CONCLUSION: The detection of plasma RNA appears to be sensitive and specific; negative test results may be used to identify false-positive serologic reactions. The detection of p24 antigen and plasma RNA can also be used to confirm HIV-1 infection in persons with indeterminate serologic results associated with early seroconversion or late-stage disease.

Blotting, Western↗

PubMed1997

Viral RNA in the resolution of human immunodeficiency virus type 1 diagnostic serology.

BACKGROUND: Assays for human immunodeficiency virus (HIV) antibody testing are characterized by very high levels of sensitivity and specificity. Nonetheless, serologic testing of HIV-infected individuals before they produce multispecific HIV antibodies will not detect and confirm those individuals as positive for HIV. This study was carried out to determine whether viral RNA in such specimens is detectable in a quantitative RNA polymerase chain reaction assay. STUDY DESIGN AND METHODS: Study specimens were identified through the United States military HIV testing program. Thirty-five individuals were studied whose HIV type 1 (HIV-1) infection status was serologically inconclusive at initial testing (i.e., reactive on enzyme immunoassay, nondiagnostic or nonreactive on Western blot), but who were documented to be infected (n = 15) or uninfected (n = 20) through the testing of subsequently collected (follow-up) sera. HIV-1 RNA was detected in sera by the use of a commercially available, quantitative, reverse transcriptase-polymerase chain reaction assay. RESULTS: Specimens from 15 individuals subsequently confirmed to be positive for HIV antibody were all positive for HIV-1 RNA. Specimens from 19 of 20 individuals subsequently confirmed to be negative for HIV antibody were negative for HIV-1 RNA. In the one HIV-1 RNA-positive serum from this group, the RNA copy number was low; specimen contamination during prior laboratory testing was suspected. CONCLUSION: Viral RNA was detected in specimens collected for serologic diagnosis of HIV infection in which no special precautions had been taken to preserve the nucleic acid. Such molecular methods potentially add a much needed tool to current HIV testing algorithms.

AIDS Serodiagnosis↗

PubMed1998

An Israeli family with six cisAB members: serologic and enzymatic studies.

BACKGROUND: The cisAB blood type is a rare phenomenon in which both the A and B blood types are inherited from a single parent. Several forms of this phenotype have been characterized that differ with respect to serologic reactions and the activities of the gene-encoded blood group A and B transferases. STUDY DESIGN AND METHODS: The cisAB blood type was suspected when a baby typed as blood group O was born to a mother whose blood group was AB. Family studies revealed four generations in whom the pattern of inheritance could be explained only by the inheritance of the cisAB genotype. Blood and saliva samples from the family were tested serologically and assayed for the relevant glycosyltransferases. Samples suitable for DNA analysis were not available. RESULTS: Six family members were shown serologically to be of the cisAB type. The A and B transferases in the sera of these individuals were 20 to 35 and 25 to 50 percent of those obtained for A and B individuals, respectively. The enzymic characteristics of the A and B transferases were determined. The A transferase in the sera of the cisAB persons did not bind to agarose beads. CONCLUSION: The family described carries the cisAB gene, which encodes production of A and B transferases that differ from those of "normal" A, AB, and B controls. This variant has properties that are distinctly different from those described in other reports.

ABO Blood-Group System↗

PubMedDate not supplied

Influence of age and purpose for testing on the cut-off selection of serological methods in bovine neosporosis.

The aim of this study was to investigate the need for different cut-off points, according to animal age and the purpose of testing, for two of the most widely used serological techniques in bovine neosporosis, IFAT and a crude antigen ELISA (Civtest, HIPRA). Therefore, the population reference sera used were defined using a combination of multiple criteria such as epidemiological/clinical and histopathological parameters and an immunoblot test. Firstly, foetuses and breeding cattle (heifers and cows) were considered as separate subpopulations for serological evaluation. Secondly, cut-off points for each serological technique (IFAT and ELISA) according to age group (foetuses and breeding cattle) and the different practical applications (detection of infection and abortion) were calculated following the receiver operating characteristics (ROC) analysis. Cut-off points were defined, for IFAT and ELISA for aborted breeding cattle and for IFAT alone in the case of the foetuses, assuming an equivalent cost of false positive and negative results. In infected breeding cattle, for IFAT and ELISA and in foetuses for ELISA, two possible cut-off values were obtained, one for a maximum sensitivity and one for a maximum specificity and the intervals of unclear results were defined. In this case, a cut-off value for equal sensitivity and specificity was also estimated. When cut-off points for infected breeding cattle, 1:100-1:250 for IFAT and 0.306-0.451 for ELISA were applied to a target population, optimal and similar negative and positive predictive values together with similar apparent and true prevalence results were observed suggesting the possibility of using both tests interchangeably.

Abortion, Veterinary↗

PubMed1999

Does quantitative serologic testing for Helicobacter pylori predict peptic ulcer disease in cirrhosis?

BACKGROUND: Helicobacter Pylori is strongly associated with peptic ulcer disease. A correlation between high IgG serum antibody concentrations and a clinical diagnosis has been reported. It has been recognized that peptic ulcer disease occurs with increased frequency in cirrhosis. In this study, we attempted to establish a relation between the magnitude of serum IgG antibody to H pylori and the endoscopic diagnoses in H pylori-infected cirrhotic patients. METHODS: All cirrhotic patients who had undergone esophagogastroduodenoscopy with a positive H pylori IgG serology and who did not receive anti-H pylori treatment or take medications noxious to the gastroduodenal mucosa were included in the study. H pylori IgG serology was determined by an enzyme-linked immunosorbent assay with values of greater than 50 units/mL being seropositive. The functional reserve of cirrhosis was classified by modified Pugh-Child criteria. RESULTS: One hundred four seropositive cirrhotic patients were recruited. The serum IgG titers ranged from 51 to 1200 units/mL with a peak frequency at 50 to 99 units/mL (35. 6%). Statistical analysis did not reveal any relation between the quantitative H pylori IgG values and the endoscopic diagnoses, which included gastric ulcers, duodenal ulcers, gastroduodenal erosions, and normal findings. CONCLUSIONS: In cirrhosis, the magnitude of H pylori IgG serology cannot be used to predict the presence or absence of peptic ulcer disease.

Adult↗

PubMed2000

A novel serological test for the diagnosis of central venous catheter-associated sepsis.

OBJECTIVES: To determine the sensitivity and specificity of a novel antibody test for the diagnosis of intravascular catheter-related infections due to coagulase-negative staphylococci. METHODS: Sixty-seven patients diagnosed as having central venous catheter (CVC)-associated sepsis based on strict clinical criteria, including positive blood cultures, were compared to 67 patients with a CVC in situ who exhibited no evidence of sepsis. An ELISA serological test based on a novel short-chain lipoteichoic acid antigen isolated from coagulase-negative staphylococci (CNS) was used to determine the patient's serological response (IgG and IgM) to CVC sepsis caused by CNS. The specificity and sensitivity of the test was determined. RESULTS: There was a significant increase in the antibody levels (IgG and IgM) to the short-chain lipoteichoic acid in patients with CVC-associated staphylococcal sepsis as compared to the control patients. CONCLUSIONS: This new serological method may offer a useful diagnostic test for intravascular catheter infections caused by staphylococci.

Adolescent↗

PubMed2001

Systemic sclerosis in 3 US ethnic groups: a comparison of clinical, sociodemographic, serologic, and immunogenetic determinants.

OBJECTIVE: To determine whether ethnic factors influence the presentation, serologic expression and immunogenetics of systemic sclerosis (SSc), patients from 3 ethnic groups were compared for clinical features, SSc-associated autoantibodies, and human leukocyte antigen (HLA) class II alleles. METHODS: Fifty-four Hispanics, 28 African Americans, and 79 whites from Texas with recent-onset (less than 5 years) SSc enrolled in a prospective longitudinal study were assessed for sociodemographic, clinical, immunologic, immunogenetic, behavioral, and psychologic parameters using validated instruments and standard laboratory techniques. Serologic and immunogenetic characteristics from these patients and larger retrospective SSc cohorts of the same ethnic groups also were examined. RESULTS: Hispanics and African Americans in the prospective cohort were more likely to have diffuse skin involvement, skin pigmentary changes, digital ulcers, pulmonary hypertension (African Americans), and an overall lower sociodemographic status than whites, who had more facial telangiectasia and hypothyroidism. In the larger combined prospective and retrospective groups of SSc patients, whites were likely to have more anticentromere antibodies (ACA) and African Americans more anti-U1-ribonucleoprotein (RNP) and anti-U3-RNP (fibrillarin) autoantibodies. HLA-DQB1*0301 was significantly associated with SSc per se in all 3 ethnic groups; HLA-DRB1*11 correlated with the anti-topoisomerase I antibody response, and HLA-DRB1*01, DRB1*04, and DQB1*0501 with ACA. CONCLUSIONS: Important sociodemographic, clinical, and serologic differences exist between whites, African Americans, and Hispanics, despite shared genetic (HLA class II) predisposing factors. The impact of these differences on prognosis remain to be determined.

Adult↗

PubMed2006

[Serologic early diagnosis of pneumonia caused by Mycoplasma pneumoniae].

BACKGROUND AND OBJECTIVE: The definitive diagnosis of M. pneumoniae is encumbered by the lack of a rapid and cost-effective test of detection. The study aimed to determine if a single serological test within the first days of hospital admission may be relevant for the diagnosis of community-acquired pneumonia (CAP) caused by M. pneumoniae. PATIENTS AND METHODS: Patients with suspected of CAP were investigated for microbiological diagnosis based on respiratory samples (bronchoalveolar lavage, bronchial aspirate, sputum, throat rinse), blood culture and serology for detection of atypical organisms and viruses. Patients with M. pneumoniae antibody titers > or = 1:160 were further investigated by polymerase chain reaction (PCR) for detection of M. pneumoniae in respiratory samples. The group of CAP by M. pneumoniae (MP-CAP) included patients with serum titers > 1:160 of M. pneumoniae antibodies (based on a single antibody determination at admission). The control group (non-MP-CAP group) included patients with CAP by pathogens other than M. pneumoniae or with no definitive bacteriological diagnostic. RESULTS: Twenty adults with MP-CAP and 20 controls with non-MP-CAP were included. PCR was positive in 18/20 (90 %) of the MP-CAP group and negative in the 9/9 (100 %) investigated patients of the non-MP-CAP group. The duration of symptoms prior to hospital admission was rather long in both groups (mean 13.2 days in the MP-CAP group and 12,7 days in the non-MP-CAP group). The MP-CAP group was significantly younger (p = 0.002), had subsequently less associated comorbidities (p < 0.001) and less purulent sputum (p = 0.003) than the non-MP-CAP group. CONCLUSION: Single serology at admission with M. pneumoniae antibody titers > 1:160 may be useful for the diagnosis of CAP caused by M. pneumoniae in hospitalized patients with a long duration of symptoms (> 12 days).

Adult↗

PubMedDate not supplied

[How often can the clinical diagnosis of exanthema subitum be confirmed with the HHV-6 serology test].

Three years ago a newly recognized human herpes virus (HHV-6) was identified to be the causative agent for exanthem subitum (roseola infantum). So far this diagnosis was suggested chiefly by excluding other infections and the presence of a typical course of the disease. To find out how often the clinical diagnosis can be confirmed serologically, we asked five pediatricians in private practice as well as residents of the out-patient and infant departments of our hospital to obtain paired heparinized blood samples of any child suspicious for exanthem subitum. 36 children with clinically suspected exanthem subitum and a mean age of 14.2 (5-71) months were included in this prospective study. Indirect immunofluorescence was used to detect IgG and IgM antibodies to HHV-6. In 22 children (61%) the clinical diagnosis was confirmed serologically. IgM antibody was found in only 16 of these 22 children. In 8 patients the results were ambiguous. Three had in the same time a doubtful seroconversion to other viruses of the herpes group (HSV twice; EBV once), in four children there was an insufficient rise in IgG antibodies without presence of an IgM response, and once we found a very high HHV-6 specific antibody titre (greater than 1:80) in both serum samples. In 6 children neither a seroconversion nor a rise in HHV-6 antibody titre were found. Retrospectively, only three of these children had a clinical course really typical for exanthem subitum. We conclude that in most cases the clinical diagnosis of exanthem subitum will be confirmed by serological examination.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Viral↗

PubMed1990

[Value and status of neurologic, serologic, internal medicine and orthopedic studies in routine diagnosis of sudden deafness].

One hundred and eighteen patients with acute unilateral sensorineural hearing loss were examined. Diagnosis included a neurological, orthopedic, and internal medical examination. Serological tests were performed including influenza-, parainfluenza-, adenovirus-, RS-virus, enterovirus-, morbilli-, varicella- and cytomegalie-virus-KBR, also the serological tests for toxoplasmosis, rheuma, lues, mycosis, and Borrelia. The examinations allowed conclusions to be drawn about a possible etiology in five of the patients only: in one patient it was possible to detect an acute infection with morbilli virus; in two other patients, an acute lues infection was detected. In two other patients, neurological examinations showed symptoms of a brainstem disease. The authors' experience shows that the following examinations are useful in the diagnosis of acute unilateral sensorineural hearing loss: the recording of acoustically evoked brainstem potentials, an otoneurological examination, a neurological examination to detect a possible centrally located reason for the hearing loss, serological examinations for lues, toxoplasmosis, Borrelia, and the virus KBR if there is any suspicion of a previous virus infection. An orthopedic examination should be performed, if functional aspects, especially of the craniocervical segment are under consideration.

Adult↗

PubMed2001

Confirmatory serologic testing for acute toxoplasmosis and rate of induced abortions among women reported to have positive Toxoplasma immunoglobulin M antibody titers.

OBJECTIVE: Results obtained with commercial testing kits for immunoglobulin M Toxoplasma antibodies may be inaccurate or may be inaccurately interpreted, which may influence whether a woman decides to terminate the pregnancy. This study was undertaken to determine whether confirmatory testing at a reference laboratory and communication of the results and an expert interpretation to the patient's physician would affect the rate of induced abortions among pregnant women with positive results of testing for immunoglobulin M Toxoplasma antibodies in outside laboratories. STUDY DESIGN: This was a retrospective cohort study of 811 consecutive pregnant women for whom the toxoplasma serologic profile was performed at a reference laboratory. Almost all the patients had been informed by their physicians that a result of a test for immunoglobulin M Toxoplasma antibodies performed in an outside laboratory was positive. Women were separated into those with a toxoplasma serologic profile result suggestive of a recently acquired infection (group 1) and those with a result suggestive of an infection acquired in the more distant past (group 2). Physician reports of induced abortions were used to determine rates of induced abortion in groups 1 and 2. RESULTS: Of the 811 women 321 (39.6%) were considered likely to have a recent infection (group 1) and 490 (60.4%) were considered likely to have a past infection (group 2). Physicians reported pregnancy outcomes for 433 (53.4%) of 811 women (65.1% and 45.7% in groups 1 and 2, respectively). Whereas 36 of 209 women in group 1 (17.2%) terminated the pregnancy, only 1 of 224 women in group 2 (0.4%) chose abortion (P <.001). CONCLUSION: Confirmatory serologic testing in a reference laboratory and communication of the results and their correct interpretation by an expert to the patient's physician decreased the rate of unnecessary abortions by approximately 50% among women for whom positive immunoglobulin M Toxoplasma test results had been reported by outside laboratories.

Abortion, Induced↗

PubMed1971

Serological and structural properties of Mason-Pfizer monkey virus isolated from the mammary tumor of a Rhesus monkey.

We describe here serological and structural properties of a virus, Mason-Pfizer Monkey Virus (M-PMV), isolated from a simian mammary tumor. This virus is morphologically similar to the known oncogenic RNA viruses (oncornaviruses). It has a 60-70S RNA, and its replication is inhibited by actinomycin. Antisera prepared against the virus isolated by density-gradient centrifugation identify at least two viral structural antigens. Immunodiffusion studies show that this virus is serologically unrelated to three types of simian foamy viruses, visna virus, and the known oncornaviruses. Immunofluorescence reveals that the structural proteins of the virus are synthesized cytoplasmically. Although M-PMV productively infects human cells in vitro, serological analysis does not show the presence of M-PMV antigens in human neoplasia.

Adult↗

PubMed1981

Serologically distinguishable alterations in the molecular specificity of cell cohesion during morphogenesis in Dictyostelium discoideum.

Cells of the mutant strain JC-5 of the slime mold Dictyostelium discoideum exhibit at a specific, late developmental stage a temperature-sensitive morphogenetic defect associated with the loss of cell cohension. We show that at the restrictive temperature, the loss of cohesion and attendant dispersal of multicellular aggregates is associated with the disappearance or sequestration of a plasma membrane-bound moiety capable of reacting with and, hence, absorbing cohesion-blocking Fab. At the permissive temperature, the maintenance of cohesiveness past the critical stage or the recovery of lost cohesiveness is correlated with the presence or reappearance of the Fab-reactive moiety.This moiety is absent or sterically incapable of reaction with Fab preparations at an earlier developmental stage in either mutant or wild-type cells-i.e., at a time when they have just entered into multicellular aggregates. Conversely, a serologically distinguishable membrane-bound moiety present in the early mutant or wild-type cells, whose reaction with homologous Fab also precludes their cohesion, is absent or serologically unreactive in either mutant or wild-type cells that are at comparable late developmental stages. We conclude that the cohesive moiety responsible for initiation of cell aggregates is supplanted by or transformed into a serologically distinct, cohesive complex responsible for the maintenance of the aggregate's integrity through the later stages of development.

Journal Article↗

PubMed1988

Evaluation of serology as a tool for malaria surveillance in East Champaran District of Bihar, India.

The indirect immunofluorescence test was evaluated as a tool for malaria surveillance. The population of 12 villages in the East Champaran District of Bihar with a low annual parasitic index and a low annual blood examination rate was surveyed in order to confirm the low endemicity of malaria in these villages. Two specimens of blood, one taken during the pre-transmission season and one taken during the post-transmission season, were collected for parasitological and serological studies. The paired samples showed no parasite positivity in the study population in both surveys. All the villages had very low serological titres. However, the presence of malaria antibodies in the zero to five years age group (the sentinel group) indicated that malaria transmission occurred in the study area at a very low level. The seropositivity and the geometric mean titre were lower in the pre-transmission season than in the post-transmission season, but the overall reduction in geometric mean titre, which was very low throughout the study, was not statistically significant. The study emphasizes the importance of serological tests in malaria surveillance.

Adolescent↗

PubMed1988

Serological evaluation of ultrasound examination for chronic schistosomiasis japonica in a previously endemic area--the Chikugo River Basin, Japan.

Ultrasound diagnosis of chronic schistosomiasis japonica was assessed by comparison with the results of serological tests using enzyme-linked immunosorbent assay (ELISA) with egg and adult worm antigen, and the circumoval precipitation test. The subjects were persons resident in the Chikugo River Basin in Kyushu, southwest Japan, where schistosomiasis used to be highly prevalent. Of 93 individuals with a past history of infection, 37 (39.8%) presented the characteristic echo pattern of the disease (network, sieve, mottled or mixed pattern). In the serological tests, the ultrasound (US)-positive subjects showed a significantly higher IgG antibody-positive rate in ELISA (81.1% for egg-ELISA), than the US-negative subjects (37.5% for egg-ELISA). Individuals bearing dead Schistosoma japonicum eggs proven by tissue biopsy showed a similar antibody-positive rate (76.5% for egg-ELISA) to that of the US-positive subjects. Sera of a group which had no schistosomiasis characteristic echo pattern, but had liver fibrosis, hepatomegaly or liver cirrhosis as shown by US, were also highly positive (71.4% for egg-ELISA). The present serological studies thus confirmed the usefulness of ultrasound diagnosis for chronic schistosomiasis japonica. Furthermore, we were able to determine certain indications of liver abnormality currently undefined in the normally utilized US classifications.

Adult↗

PubMed2000

Prevalence of Coeliac disease in the general population of northern Spain. Strategies of serologic screening.

BACKGROUND: Coeliac disease (CD) is common in Western countries. In Spain, however, no studies exist on its prevalence. The best method for serologic screening is also unknown. METHODS: We determined the IgA and IgG antigliadin antibodies (AGA) and IgA antiendomysium antibodies (AEA) in a sample of 1170 randomly selected subjects from a health area in northern Spain. The prevalence of CD was calculated with a two-step serologic screening method (first IgA and IgG AGA and then AEA in those positive for AGA) or with only one step with AEA determination. Diagnosis was confirmed by small-intestinal biopsy. RESULTS: When using a two-step strategy, we found 174 (15%) subjects with AGA. Only one of these was confirmed by means of AEA (prevalence of CD = 0.9/1000). Two subjects were found to be positive when a one-step strategy was used (prevalence of CD = 1.7/1000). This yielded an economic saving of 19% with regard to the use of a two-step strategy. One new case of CD in a seronegative subject was diagnosed during the study (real prevalence of CD = 2.6/1000; 95% confidence interval = 0.7-8.2). CONCLUSIONS: The prevalence of CD in Northern Spain is 2.6/1000 (1:389). One-step serologic screening (AEA) is both more economical and more sensitive than the two-step procedure (first AGA and then AEA if AGA is positive).

Adolescent↗