MOG encephalomyelitis: international recommendations on diagnosis and antibody testing.

Over the past few years, new-generation cell-based assays have demonstrated a robust association of autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis and brainstem encephalitis, as well as with acute disseminated encephalomyelitis (ADEM)-like presentations. Most experts now consider MOG-IgG-associated encephalomyelitis (MOG-EM) a disease entity in its own right, immunopathogenetically distinct from both classic multiple sclerosis (MS) and aquaporin-4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorders (NMOSD). Owing to a substantial overlap in clinicoradiological presentation, MOG-EM was often unwittingly misdiagnosed as MS in the past. Accordingly, increasing numbers of patients with suspected or established MS are currently being tested for MOG-IgG. However, screening of large unselected cohorts for rare biomarkers can significantly reduce the positive predictive value of a test. To lessen the hazard of overdiagnosing MOG-EM, which may lead to inappropriate treatment, more selective criteria for MOG-IgG testing are urgently needed. In this paper, we propose indications for MOG-IgG testing based on expert consensus. In addition, we give a list of conditions atypical for MOG-EM ("red flags") that should prompt physicians to challenge a positive MOG-IgG test result. Finally, we provide recommendations regarding assay methodology, specimen sampling and data interpretation.

A study of high-, middle- and low-molecular weight adiponectin in urine as a surrogate marker for early diabetic nephropathy using ultrasensitive immune complex transfer enzyme immunoassay.

Background For the early identification of patients at risk of developing diabetic nephropathy, we have developed an ultrasensitive immune complex transfer enzyme immunoassay to measure adiponectin in urine. Methods We developed immune complex transfer enzyme immunoassay for adiponectin and measured urinary adiponectin from 70 healthy subjects, 35 obese non-diabetic subjects and 20 patients with diabetes. Results The urinary adiponectin concentrations in patients with diabetes (3.3 ± 10.7 ng/mg creatinine) were significantly higher than those in obese subjects (0.54 ± 0.44; P < 0.01) and healthy subjects (0.46 ± 0.42; P < 0.001). The gel filtration elution profile of urine from healthy subjects showed traces of four immunoreactive peaks (high-, medium-, low-molecular weight and monomer molecules), despite the majority of blood adiponectin being high-molecular weight. However, urinary adiponectin molecules were more frequent in low-molecular weight as the estimate glomerular filtration rate decreased. Furthermore, as blood glucose concentrations rose, middle-molecular weight and high-molecular weight increased in urine. Further, urinary adiponectin concentrations correlated with estimate glomerular filtration rate ( r = -0.61, P < 0.001), but not urinary albumin. In addition, our analysis showed a significantly ( P < 0.001) higher value for urinary adiponectin in the G2 stage of chronic kidney disease classification where urinary albumin is not elevated. Conclusion Adiponectin increases in urine as renal function decreases, and urinary adiponectin may be useful as a surrogate marker for diabetic nephropathy risk.

Lung Carcinoma Predictive Biomarker Testing by Immunoperoxidase Stains in Cytology and Small Biopsy Specimens: Advantages and Limitations.

CONTEXT: - In the burgeoning era of molecular genomics, immunoperoxidase (IPOX) testing grows increasingly relevant as an efficient and effective molecular screening tool. Patients with lung carcinoma may especially benefit from the use of IPOX because most lung carcinomas are inoperable at diagnosis and only diagnosed by small tissue biopsy or fine-needle sampling. When such small specimens are at times inadequate for molecular testing, positive IPOX results still provide actionable information. OBJECTIVE: - To describe the benefits and pitfalls of IPOX in the detection of biomarkers in lung carcinoma cytology specimens and small biopsies by summarizing the currently available commercial antibodies, preanalytic variables, and analytic considerations. DATA SOURCES: - PubMed. CONCLUSIONS: - Commercial antibodies exist for IPOX detection of aberrant protein expression due to EGFR L858R mutation, EGFR E746_A750 deletion, ALK rearrangement, ROS1 rearrangement, and BRAF V600E mutation, as well as PD-L1 expression in tumor cells. Automated IPOX protocols for ALK and PD-L1 detection were recently approved by the Food and Drug Administration as companion diagnostics for targeted therapies, but consistent interpretive criteria remain to be elucidated, and such protocols do not yet exist for other biomarkers. The inclusion of cytology specimens in clinical trials would expand patients' access to testing and treatment, yet there is a scarcity of clinical trial data regarding the application of IPOX to cytology, which can be attributed to trial designers' lack of familiarity with the advantages and limitations of cytology. The content of this review may be used to inform clinical trial design and advance IPOX validation studies.

Newborn screening for cystic fibrosis.

Since the late 1970s when the potential of the immunoreactive trypsinogen assay for early identification of infants with cystic fibrosis was first recognised, the performance of newborn blood spot screening (NBS) has been continually assessed and its use has gradually expanded. NBS for cystic fibrosis is a cost-effective strategy and, if standards of care are fully implemented and robust management pathways are in place, has a positive effect on clinical outcomes. In the past decade, NBS has undergone rapid expansion and an unprecedented number of infants with cystic fibrosis have access to early diagnosis and care. Cystic fibrosis NBS has now moved on from the development phase and is entering an era of consolidation. In the future, research should focus on the rationalisation and optimisation of existing programmes, with particular attention to bioethical implications such as unwanted detection of carriers and inconclusive diagnoses.

Inmunohistoquímica en dermatopatología: revisión de los anticuerpos utilizados con mayor frecuencia (parte II) / Immunohistochemistry in Dermatopathology: A Review of the Most Commonly Used Antibodies (Part II)

La dermatopatología incluye una larga lista de entidades, algunas con una histopatología muy similar. La immunohistoquímica representa una importante herramienta de ayuda en el diagnóstico, diagnóstico diferencial y pronóstico de muchas de las neoplasias cutáneas. La inmunohistoquímica es también la mejor técnica para determinar el origen de un tejido o la diferenciación de las células neoplásicas. En muchos casos, la inmunohistoquímica permite un diagnóstico más preciso de los distintos procesos infiltrando la piel. Este artículo revisa el papel de la inmunohistoquímica en el estudio de la diferenciación y el comportamiento biológico de la mayoría de las neoplasias que pueden afectar a la piel. Se revisan las técnicas de inmunoperoxidasa, se discute la utilidad de los anticuerpos utilizados con mayor frecuencia y se presentan una serie de problemas diagnósticos en los que la immunohistoquímica puede resultar muy útil. En cada caso, la finalidad es llegar a un diagnóstico concreto y definitivo. En esta segunda parte de nuestra revisión se analizan los anticuerpos más útiles y específicos en el estudio de las infecciones cutáneas, así como de las neoplasias epiteliales, musculares, vasculares, linfohematológicas, neurales, neuroendocrinas y melanocíticas afectando a la piel. Al final, se incluye una breve revisión del perfil inmunohistoquímico de las metástasis cutáneas de neoplasias malignas viscerales (AU)

Dermatopathology includes a long list of disorders, some of which have very similar histopathology. Immunohistochemistry is an important auxiliary tool for diagnosis and differential diagnosis, and for predicting the outcome of many skin tumors. It is also the main technique for determining the origin of a tissue or the differentiation of neoplastic cells. In many cases, immunohistochemistry provides a more accurate diagnosis of the different processes that infiltrate the skin. This review examines the role of immunohistochemistry in studying the differentiation and biological behavior of the majority of tumors that can involve the skin. We review immunoperoxidase techniques, discuss the utility of the most commonly used antibodies, and highlight a number of diagnostic problems in which immunohistochemistry may be very useful. In each case, the goal is to reach a specific and definitive diagnosis. In the second part of our review, we examine the most useful and specific antibodies in the study of skin infections and of epithelial, muscular, lymphatic and hematologic, neural, neuroendocrine, and melanocytic neoplasms that affect the skin. Finally, we include a brief review of the immunohistochemical profile of skin metastases of malignant visceral tumors (AU)

Determinación de procalcitonina en un Cobas e411 / Determination of procalcitonin on a Cobas e411

En los últimos años, la procalcitonina (PCT) ha demostrado ser la prueba más sensible para el manejo del proceso infeccioso, el diagnóstico y la estratificación de la sepsis. Ésta aporta valor pronóstico de complicaciones en pacientes postoperados y críticos, e incluso es útil como guía para la retirada del tratamiento antibiótico.Recientemente se está comercializando un nuevo inmunoensayo de electroquimioluminiscencia para la determinación de PCT (Elecsys BRAHMS PCT) con características similares a la prueba más eficaz descrita hasta ahora (PCT KRYPTOR). En el presente trabajo se procesaron 140 especímenes de pacientes con concentraciones de PCT de entre 0,02 y 47,13ng/ml, en un Cobas e411 y en un KRYPTOR; se observó que los resultados no son transferibles entre ambos métodos. Si bien la clasificación diagnóstica con los puntos de corte actuales no varía sensiblemente, es necesario un estudio más amplio para redefinir estos puntos de corte con el nuevo método. Por otra parte, se ha verificado que, aunque no hay efecto de arrastre significativo para una concentración de PCT cercana al límite superior del intervalo dinámico de la prueba, sí se observa arrastre para concentraciones más altas. Sin embargo, la modificación producida para una concentración cercana al límite de decisión clínica de 0,5ng/ml es clínicamente irrelevante, por lo que no parece necesario incorporar ninguna acción correctiva para evitar este arrastre(AU)

Over the last few years, Procalcitonin (PCT) has been shown to be the most sensitive test for the management of the infectious process, diagnosis and stratification of sepsis, prognosis of postoperative complications, and even useful for monitoring antibiotic therapy.A new electrochemical luminescence immunoassay (ECLIA) has recently been developed for measuring Procalcitonin (Elecsys BRAHMS PCT), with similar characteristics to the most efficient method described up to now (PCT KRYPTOR). In the present work, 140 patient specimens were analysed with PCT concentrations ranging 0.02–47.13ng/mL, in a Cobas e411 and a KRYPTOR analysers, and the results were found not to be transferable between methods. Although diagnostic classification using the current cut-off points did not vary significantly, a larger study will be required to redefine these cut-off points for the new method. On the other hand, there was no significant carryover effect at PCT concentrations close to the upper limit of the dynamic range, but it was observed at higher concentrations of PCT. However, at a concentration of PCT close to the clinical decision limit of 0.5ng/mL this effect seems to be clinically insignificant, thus no corrective action would be necessary to prevent carryover(AU)

Hipertiroidismo transitorio tras la curación de una enfermedad de Cushing / Transient hyperthyroidism after curing a Cushing disease

No disponible

Non-invasive, ultra-sensitive, high-throughput assays to quantify rare biomarkers in the blood.

Many diseases are easier to treat and control when detected at an early stage of disease progression. Often, disease-related antigens or biomarkers are shed from the primary site and present in the blood. Unfortunately, there are very few tests capable of detecting these rare biomarkers in the blood. A blood test would be very useful to diagnose the disease earlier, monitor effectiveness of treatments, predict recurrence, and monitor recurrence. There is certainly a need to develop assays that are ultra-sensitive, non-invasive, and high-throughput. Here we describe several highly sensitive immunological assays we have developed to detect rare serum antigens. Initially we created an assay named immuno-detection amplified by T7 RNA polymerase (IDAT). To enhance the effectiveness and streamline the procedure, this assay was amended to the facile amplification system termed fluorescent amplification catalyzed by T7 polymerase technique (FACTT). These assays have been used to analyze the tumor antigen HER2 and the prion protein PrPSc. They can also be applied to other tumor markers or antigens from a variety of diseases such as cardiovascular disease, rheumatoid arthritis, Alzheimer's disease, Parkinson's disease, and hepatitis. These tests are not limited to testing only serum, but may also be applicable to detecting biomarkers in tissue, saliva, urine, cerebrospinal fluid, etc. Clearly, the FACTT-based technology represents an important step in the detection of rare molecules in fluids or tissues for a variety of diseases.

Utilidad clínica de los anticuerpos antitiroideos / No disponible

La determinación de anticuerpos antitiroideos es parte importante dela evaluación del paciente con enfermedad tiroidea y su presencia seasocia con la reacción infl amatoria del tiroides. La mayor utilidad demedir anticuerpos anti-peroxidasa (TPO) es el diagnóstico de enfermedadautoinmune del tiroides, concretamente tiroiditis de Hashimoto.Los anticuerpos contra TPO también son una herramienta importanteen la evaluación de la mujer antes y después de la gestación. Los anticuerposcontra la tiroglobulina (Tg) deben determinarse a la par quelas mediciones de Tg en el seguimiento de los pacientes con cáncerdiferenciado de tiroides. Los anticuerpos contra el receptor de TSH puedenser estimuladores o bloqueadores. Los primeros son característicosde la enfermedad de Graves. Concentraciones elevadas de anticuerposcontra TSH después del tratamiento con fármacos antitiroideos indicanun alto riesgo de recidiva(AU)

Measurement of thyroid autoantibodies is an important component inevaluating patients with thyroid disease, since their presence is associatedwith infl ammatory thyroid reaction. The main utility of measuringanti-peroxidase (TPO) antibodies is to diagnose autoimmune thyroiddisease, specifi cally Hashimoto’s thyroiditis. TPO antibodies are alsoa useful tool in the evaluation and assessment of women before andafter pregnancy. Thyroglobulin (Tg) antibodies should be determinedwith every serum Tg measurement during the follow-up of patients withdifferentiated thyroid carcinoma. Antibodies against the TSH receptor(TSHR) may be stimulating or blocking. The former are characteristicof Graves’ disease. High TSHR antibody levels after antithyroid drugtreatment indicate a high risk of relapse(AU)

Measurement of CGRP in dried blood spots using a modified sandwich enzyme immunoassay.

Calcitonin gene-related peptide (CGRP) has roles as a neurotransmitter, neuromodulator and trophic factor. CGRP has been reported to be elevated in neonatal blood of children with autism or mental retardation as compared with normal subjects by recycling immuno-affinity chromatography (RIC). While CGRP detection in neonatal blood is thus important, it is not easy to detect CGRP in dried blood spots because of the limitations of sample volume and the specificity and the sensitivity of available assay systems. In the present study, we modified a "Sandwich Enzyme Immunoassay" for the purpose of detecting CGRP in blood spot eluate. We have prepared blood spots from blood collected from normal human subjects and measured CGRP level in eluates from these blood spots. Instead of a purification step, we have introduced a pre-incubation step and used washed erythrocytes as a dilution solution. The modified assay has good recovery and specificity and appropriate dilution curves. We have compared the eluate levels with levels in serum and plasma from the same individuals and find that CGRP levels in blood spot eluate were similar to those of serum and plasma. Thus, the newly modified EIA may be a useful method for the detection of CGRP in blood spot eluate.

Effects of hematocrit value on microparticle enzyme immunoassay of tacrolimus concentration in therapeutic drug monitoring.

The effects of hematocrit (Ht) value on microparticle enzyme immunoassay (MEIA) of tacrolimus concentration were examined in 1063 whole-blood samples from 42 transplant recipients (13 liver, 20 kidney, and 9 bone marrow transplantations). MEIA guarantees the test's assay quality for blood tacrolimus in samples with Ht values of 25% to 45%. However, 129 samples (29.3%) obtained from liver transplant recipients and 107 samples (61.5%) from bone marrow transplant recipients had lower Ht (<25%). Further, 81 blood samples (18.1%) with Ht > 45% were observed in kidney transplant patients. Twenty-five whole-blood samples with low Ht were tested by 3 assay methods for tacrolimus: MEIA, modified, corrected MEIA (cMEIA), and enzyme-linked immunosorbent assay (ELISA). MEIA gave higher blood concentrations of tacrolimus than ELISA (16.1 versus 11.0 ng/mL, P < 0.001). This difference was generated by overestimation in MEIA and was not observed in samples with normal Ht. This overestimation was eliminated by using cMEIA on samples with low Ht values: there was no difference in blood tacrolimus concentration between cMEIA and ELISA (12.3 versus 11.0 ng/mL). ELISA or cMEIA should be used for tacrolimus assay in samples obtained from bone marrow transplant recipients with anemia and from liver and kidney transplant recipients with unstable Ht values.

A critical evaluation of enzyme immunoassay kits for detection of antinuclear autoantibodies of defined specificities. II. Potential for quantitation of antibody content.

OBJECTIVE: To analyze the performance of different commercial enzyme immunoassay (EIA) kits for measuring antibody levels of antinuclear antibodies (ANA) specific for double stranded (ds) DNA, SSB/La, Sm, and Scl-70. METHODS: Twenty companies that were known major purveyors of EIA kits for detection of ANA were approached to determine their interest and willingness to participate in this study. The manufacturers were advised that they would be sent coded sera containing mixtures of the Arthritis Foundation/Centers for Disease Control reference reagents, and that they were to use their own test kits to analyze the antibody specificities of these sera and to report the data, in optical density (OD) units, or their equivalent. The analysts were blinded to the concentration of the antibodies and the specificities. RESULTS: Initially, 11 manufacturers out of 20 agreed to participate, but 2 subsequently withdrew. The commercial EIA kits have the potential of being able to quantitate specific autoantibody content to ds-DNA, SSB/La, Sm, and Scl-70. However, certain deficiencies in these kits were also detected, the most obvious being lack of uniformly good performance, with kits of certain manufacturers showing exceptional accuracy in 3 out of 4 of their antibody-specific kits and poor accuracy for a 4th kit. CONCLUSION: It is important for clinicians to appreciate that there is marked inter-manufacturer variation in the performance of EIA kits used as an aid in the diagnosis of systemic rheumatic diseases. Manufacturers need to exercise constant surveillance of kit performance and to provide assurance that such is being done. Improved EIA kits would lend themselves to reliable quantitation of antibody levels in human sera and help to determine whether serial measurement of antibody levels might be useful in monitoring disease activity.

Ferritina eritrocitaria: medición y aplicación diagnóstica / Red cell ferritin: measurement and diagnostic applications

El objeto de este estudio fue determinar la ferritina eritrocitaria (FER) por enzimoinmunoensayo como una medida directa de los depósitos de hierro intracelular presente en los eritroblastos de la médula ósea. Su uso está indicado en diferencias o en sobrecargas de hierro. Se estudiaron 40 pacientes divididos en tres grupos: 1) un grupo control (n = 16) donde se obtuvieron los siguientes valores de FER: (X ñ ES) = 24 ñ 2,5 ag/cel; 2) un grupo de pacientes ferropénicos (n = 13) con resultados de FER: (X ñ ES) = 5 ñ 0,31 ag/cel y 3) pacientes ß-talasémicos: (n = 11) donde la FER fue de (X ñ ES) = 118 ñ 11,6 ag/cel. Los resultados obtenidos mediante el test de análisis de la varianza de una vía (ANOVA) mostraron una diferencia estadísticamente significativa en los dos grupos estudiados, con respecto al grupo control. La medida de FER presenta la ventaja de ser una determinación cuantitativa que puede ser realizada en sangre periférica y no se modifica en aquellos casos en los cuales la presencia de procesos inflamatorios, infecciosos o neoplásicos, falsean los resultados de la ferritina sérica (Fs), que pueden mostrar valores altos no relacionados con la cantidad de hierro de depósito. Se concluye que a pesar de su especificidad y sus ventajas diagnósticas, el valor de la FER tiene una aplicación limitada, dad en parte por la preparación de la muestra y la complejidad del método usado para medirla (AU)

Ferritina eritrocitaria: medición y aplicación diagnóstica / Red cell ferritin: measurement and diagnostic applications

El objeto de este estudio fue determinar la ferritina eritrocitaria (FER) por enzimoinmunoensayo como una medida directa de los depósitos de hierro intracelular presente en los eritroblastos de la médula ósea. Su uso está indicado en diferencias o en sobrecargas de hierro. Se estudiaron 40 pacientes divididos en tres grupos: 1) un grupo control (n = 16) donde se obtuvieron los siguientes valores de FER: (X ñ ES) = 24 ñ 2,5 ag/cel; 2) un grupo de pacientes ferropénicos (n = 13) con resultados de FER: (X ñ ES) = 5 ñ 0,31 ag/cel y 3) pacientes ß-talasémicos: (n = 11) donde la FER fue de (X ñ ES) = 118 ñ 11,6 ag/cel. Los resultados obtenidos mediante el test de análisis de la varianza de una vía (ANOVA) mostraron una diferencia estadísticamente significativa en los dos grupos estudiados, con respecto al grupo control. La medida de FER presenta la ventaja de ser una determinación cuantitativa que puede ser realizada en sangre periférica y no se modifica en aquellos casos en los cuales la presencia de procesos inflamatorios, infecciosos o neoplásicos, falsean los resultados de la ferritina sérica (Fs), que pueden mostrar valores altos no relacionados con la cantidad de hierro de depósito. Se concluye que a pesar de su especificidad y sus ventajas diagnósticas, el valor de la FER tiene una aplicación limitada, dad en parte por la preparación de la muestra y la complejidad del método usado para medirla

[Past, present and future of enzyme immunoassay].

Enzyme immunoassay (EIA) is one of the most popular non-isotopic immunoassay methods, with various clinical applications. After radioimmunoassay was developed by Yalow and Berson, its competitive binding principle was combined with enzyme labeling techniques and its application has been expanded by developing various procedures. Theoretically, EIA is more sensitive than RIA, being able to measure levels as minute as some attomole levels. Automated enzyme immunoassay systems have further improved its intra-laboratory variation, but relatively large variations among different reagent kits must be improved. Highly sensitive EIA systems should allow wider clinical applications.

[Isozyme analysis by enzyme immunoassay (EIA)--clinical significance and future prospect].

Serum isozymes are widely used for estimating the origin or the degree of injury. The significance and future prospect of enzyme immunoassay (EIA) for the determination of isozymes are summarized in this paper. EIAs were developed for isozymes, e.g., unstable or labile, and indistinguishable by electrophoresis or ion-exchange column chromatography EIA can measure isozyme fragments with no catalytic activity. The catalytic activity of isoenzymes released from tissues disappears immediately but immunologically active isozymes or its fragment may remain in the blood for a longer period. The determination of isozymes by EIA provides an accurate mass, released from the injury. The combination assay of catalytic activity with isozyme mass by EIA may open a new approach for the disease.