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Archives of Pathology & Laboratory... Aug 2013Immunoassays are commonly used for clinical diagnosis, although interferences have been well documented. The streptavidin-biotin interaction provides an efficient and...
Immunoassays are commonly used for clinical diagnosis, although interferences have been well documented. The streptavidin-biotin interaction provides an efficient and convenient method to manipulate assay components and is currently used in several immunoassay platforms. To date, there has been no report in the literature of interference from endogenous anti-streptavidin antibodies; however, such antibodies would potentially affect multiple diagnostic platforms. We report results from a patient being treated for thyroid dysfunction who demonstrated a T-uptake result of less than 0.2 and a nonlinear thyroid stimulating hormone dilution that suggested an immunoassay interference. Protein-A sepharose pretreatment corrected the nonlinear dilution and revealed an interference trend of falsely decreased results, as measured by sandwich assay, and falsely elevated results, as measured by competitive assay. The results of streptavidin-agarose adsorption were comparable to adsorption with protein-A sepharose. To our knowledge, this is the first published description of an endogenous anti-streptavidin antibody interfering with clinical laboratory assays.
Topics: Antibodies, Heterophile; Biotin; Diagnostic Errors; Humans; Hyperthyroidism; Immunoassay; Immunosorbent Techniques; Male; Middle Aged; Sepharose; Streptavidin; Thyrotropin; Thyroxine
PubMed: 23899071
DOI: 10.5858/arpa.2012-0270-CR -
Clinical Chemistry May 2005
Topics: Animals; Antibodies, Heterophile; Antibody Specificity; Genetic Engineering; Humans; Immunoassay; Immunoglobulin Fab Fragments; Immunoglobulin Variable Region; Peptide Library; Recombinant Fusion Proteins
PubMed: 15855662
DOI: 10.1373/clinchem.2005.049221 -
Medizinische Klinik (Munich, Germany :... Sep 2001Heterophilic antibodies represent a great danger to clinical care by producing false-positive values for certain markers. Too large confidence in specificity of... (Review)
Review
BACKGROUND
Heterophilic antibodies represent a great danger to clinical care by producing false-positive values for certain markers. Too large confidence in specificity of laboratory markers together with lack of communication between clinicians and clinical chemists may lead to unnecessary interventional diagnostic and therapeutic procedures. The prevalence of heterophilic antibodies is probably much higher than assumed up till now and several markers can be affected.
AIM
In this review for clinicians, we explain formation of heterophilic antibodies, mechanisms of interference and present clinical data about affected markers and "side effects" from the literature. Furthermore we discuss possible alternatives and measures against this phenomenon. We consider broad awareness of this problem among clinicians the most important action to avoid further harm to patients.
Topics: Antibodies, Heterophile; Communication; False Positive Reactions; Humans; Immunoassay; Interprofessional Relations
PubMed: 11603117
DOI: 10.1007/pl00002238 -
The Journal of Clinical Endocrinology... Jul 2003Serum thyroglobulin (Tg) measurement is a major means of detecting thyroid cancer recurrence. Unlike anti-Tg autoantibody interferences, heterophile antibody (HAB)...
Serum thyroglobulin (Tg) measurement is a major means of detecting thyroid cancer recurrence. Unlike anti-Tg autoantibody interferences, heterophile antibody (HAB) immunoassay interferences are not well recognized by laboratorians or clinicians as a Tg assay problem. When HAB interferences occur, they usually result in false positive test results. With the current trend to treat some thyroid cancer patients with radioiodine on the basis of an elevated serum Tg result alone, this has the potential to result in unwarranted therapy. We evaluated the prevalence of HAB interference in a commonly used automated immunoassay in 1106 consecutive specimens with Tg values greater than 1 ng/ml. All Tg measurements were repeated after sample incubation in heterophile-blocking tubes (HBT). Results, which showed a more than 3 SD percentage difference from the original result, were considered to suffer from HAB interference. All possible interferences were confirmed by dilution testing. After HBT treatment, Tg levels dropped to less than 1 ng/ml in 32 specimens (P < 0.0000001), 20 of which fell to less than 0.1 ng/ml (P < 0.00002). Of these 20, 17 were anti-Tg autoantibody negative, and all 32 showed a fall of greater than 3 SD percentage (>56.91%) compared with the original result. There were also two samples that showed a significant increase of greater than 56.91% after HBT treatment. HAB interference is relatively prevalent (1.5-3%) in a commonly used automated Tg assay and can lead to clinically significant artifacts. It is currently unknown, but possible, that other immunometric Tg assays suffer from similar problems. Unless a Tg assay is confirmed to be free of HAB interference or uses additional blocking steps, as ours now does, HAB interference should be suspected if Tg results do not fit the clinical picture.
Topics: Antibodies, Blocking; Antibodies, Heterophile; Cohort Studies; Humans; Immunoassay; Neoplasm Recurrence, Local; Reproducibility of Results; Seroepidemiologic Studies; Thyroglobulin; Thyroid Neoplasms
PubMed: 12843145
DOI: 10.1210/jc.2003-030122 -
Clinica Chimica Acta; International... Apr 2007
Topics: Antibodies, Heterophile; Artifacts; Chromogranin A; Cross Reactions; False Positive Reactions; Humans; Immunoassay; Neuroendocrine Tumors
PubMed: 17240364
DOI: 10.1016/j.cca.2006.12.001 -
Current Opinion in Organ Transplantation Feb 2019The use of genetically modified donor pigs has been integral to recent major advances in xenograft survival in preclinical nonhuman primate models. CRISPR-Cas9 gene... (Review)
Review
PURPOSE OF REVIEW
The use of genetically modified donor pigs has been integral to recent major advances in xenograft survival in preclinical nonhuman primate models. CRISPR-Cas9 gene editing technology has dramatically accelerated the development of multimodified pigs. This review examines the current and projected impact of CRISPR-Cas9-mediated donor modification on preventing rejection and potentially promoting tolerance of porcine xenografts.
RECENT FINDINGS
CRISPR-Cas9 has been used to engineer several genetic modifications relevant to xenotransplantation into pigs, including glycosyltransferase knockouts (GGTA1, CMAH, β4GALNT2, A3GALT2 and combinations thereof), other knockouts (SLA-I, ULBP1, PERV and GHR), and one knock-in (anti-CD2 monoclonal antibody transgene knocked into GGTA1). Although the use of these pigs as donors in preclinical nonhuman primate models has been limited to a single study to date, in-vitro analysis of their cells has provided invaluable information. For example, deletion of three of the glycosyltransferases progressively decreased the binding and cytotoxicity of preexisting immunoglobulin G and immunoglobulin M in human sera, suggesting that this 'triple-KO' pig could be a platform for clinical xenotransplantation.
SUMMARY
CRISPR-Cas9 enables the rapid generation of gene-edited pigs containing multiple tailored genetic modifications that are anticipated to have a positive impact on the efficacy and safety of pig-to-human xenotransplantation.
Topics: Animals; Animals, Genetically Modified; Antibodies, Heterophile; CRISPR-Cas Systems; Humans; Swine; Transplantation, Heterologous
PubMed: 30480643
DOI: 10.1097/MOT.0000000000000589 -
Pediatric Emergency Care Mar 2004Mild splenomegaly is common in patients with Epstein-Barr virus-associated infectious mononucleosis. Massive splenomegaly, however, is rare and requires further...
Mild splenomegaly is common in patients with Epstein-Barr virus-associated infectious mononucleosis. Massive splenomegaly, however, is rare and requires further evaluation to exclude other causes. We report an adolescent girl with previously undiagnosed type 1 Gaucher disease who presented with massive splenomegaly. The diagnosis of her underlying condition was hampered by the presence of a positive heterophile antibody test for infectious mononucleosis.
Topics: Adolescent; Antibodies, Heterophile; Antibodies, Viral; Antibody Specificity; Bone Marrow Examination; Diagnostic Errors; False Positive Reactions; Fatigue; Female; Fever; Gaucher Disease; Glucosylceramidase; Hepatomegaly; Herpesvirus 4, Human; Humans; Infectious Mononucleosis; Pharyngitis; Splenectomy; Splenomegaly
PubMed: 15094578
DOI: 10.1097/01.pec.0000117929.65522.d7 -
Transplantation Jan 2004The recent availability of pigs homozygous for alpha1,3-galactosyltransferase gene knockout, and improved immunosuppressive regimens that prevent an elicited antibody... (Review)
Review
The recent availability of pigs homozygous for alpha1,3-galactosyltransferase gene knockout, and improved immunosuppressive regimens that prevent an elicited antibody response, are expected to contribute to significantly increased survival of pig organs transplanted into primates, bringing clinical trials of xenotransplantation closer. Patients highly sensitized to human leukocyte antigens, who may be precluded from obtaining a human donor organ, would be one group that might benefit from xenotransplantation. However, there have been few studies on whether there is cross-reactivity of anti-human leukocyte antigen antibodies with pig antigens. What data there are suggest that such cross-reactivity exists and that this may be detrimental to the outcome after transplantation of a pig organ. Neither is it known whether sensitization after a pig xenograft would preclude subsequent allotransplantation, although the data available suggest that this will not be the case. Further investigation on allo- and xenoantibody cross-reactivity is required.
Topics: Animals; Antibodies, Heterophile; Cross Reactions; HLA Antigens; Humans; Immunization; Isoantibodies; Transplantation Immunology
PubMed: 14724427
DOI: 10.1097/01.TP.0000105116.74032.63 -
Critical Reviews in Oncology/hematology Apr 2001Overexpression of epidermal growth factor receptor (EGFr) has been demonstrated on many human tumors, and the increase in receptor expression levels has been linked with... (Review)
Review
Overexpression of epidermal growth factor receptor (EGFr) has been demonstrated on many human tumors, and the increase in receptor expression levels has been linked with a poor clinical prognosis. Blocking the interaction of EGFr and the growth factors could lead to the arrest of tumor growth and possibly result in tumor cell death. To this end, using XenoMouse technology, ABX-EGF, a human IgG2 monoclonal antibody (mAb) specific to human EGFr, has been generated. ABX-EGF binds EGFr with high affinity (5x10(-11) M), blocks the binding of both EGF and transforming growth factor-alpha (TGF-alpha) to various EGFr-expressing human carcinoma cell lines, and inhibits EGF-dependent tumor cell activation, including EGFr tyrosine phosphorylation, increased extracellular acidification rate, and cell proliferation. In vivo ABX-EGF prevents completely the formation of human epidermoid carcinoma A431 xenografts in athymic mice. More importantly, administration of ABX-EGF without concomitant chemotherapy results in complete eradication of established tumors. No tumor recurrence was observed for more than 8 months following the last antibody injection, further indicating complete tumor cell elimination by the antibody. Inhibition of human pancreatic, renal, breast and prostate tumor xenografts which express different levels of EGFr by ABX-EGF was also achieved. Tumor expressing more than 17000 EGFr molecules per cell showed significant growth inhibition when treated with ABX-EGF. ABX-EGF had no effect on EGFr-negative tumors. The potency of ABX-EGF in eradicating well-established tumors without concomitant chemotherapy indicates its potential as a monotherapeutic agent for treatment of multiple EGFr-expressing human solid tumors, including those where no effective chemotherapy is available. Utilization of mAbs directed to growth factor receptors as cancer therapeutics has been validated recently by the tumor responses obtained from clinical trials with Herceptin, the humanized anti-HER2 antibody, in patients with HER2 overexpressing metastatic breast cancer. Being a fully human antibody, ABX-EGF is anticipated to exhibit a long serum half-life and minimal immunogenicity with repeated administration, even in immunocompetent patients. These results demonstrate the potent anti-tumor activity of ABX-EGF and its therapeutic potential for the treatment of multiple human solid tumors that overexpress EGFr.
Topics: Animals; Antibodies, Heterophile; Antibodies, Monoclonal; Antineoplastic Agents; Epidermal Growth Factor; Humans; Mice; Neoplasms; Panitumumab
PubMed: 11255078
DOI: 10.1016/s1040-8428(00)00134-7 -
Journal of Immunological Methods Jan 1984A small proportion of sera submitted for routine immunofluorescent antibody screening contains heterophile antibodies. The reaction patterns produced by the heterophile...
A small proportion of sera submitted for routine immunofluorescent antibody screening contains heterophile antibodies. The reaction patterns produced by the heterophile antibody may be confused with or mask specific autoantibody patterns, leading to false positive or false negative autoantibody results. In this study we report the development of a method in which fresh sheep red cells are used to absorb heterophile antibody from sera without affecting specific autoantibody which may be present. This technique was used on a panel of 142 sera known to contain heterophile antibody but not initially reported as containing specific autoantibodies by immunofluorescence. After absorption with sheep red cells the heterophile antibody was completely removed from the sera under test and 27 (19%) specimens were shown to contain previously undetected autoantibodies. Only 6 (4%) of the sera, however, contained autoantibodies at a titre which would be reported as a positive result on routine screening. These results suggest that there may be a significant number of sera submitted for routine autoantibody screening which contain autoantibodies that are masked by the presence of heterophile antibody. Selective use of the absorption technique offers a simple solution to this problem.
Topics: Absorption; Animals; Antibodies, Heterophile; Autoantibodies; Autoimmune Diseases; Blood Group Antigens; Cattle; Fluorescent Antibody Technique; Guinea Pigs; Haplorhini; Hemagglutination Tests; Horses; Humans; Mice; Rabbits; Rats; Sheep; Swine
PubMed: 6420473
DOI: 10.1016/0022-1759(84)90248-5