RESUMEN
Primary immunodeficiency is seen in an estimated one in 1200 people, and secondary immunodeficiency is increasingly common, particularly with the use of immunosuppresion, cancer therapies and the newer biological therapies such as rituximab. Delays in the diagnosis of immunodeficiency predictably lead to preventable organ damage. Examples of abnormal pathology tests that suggest immunodeficiency from all laboratory specialities are given, where vigilant interpretation of abnormal results may prompt earlier diagnosis. If immunodeficiency is suspected, suggested directed testing could include measuring immunoglobulins, a lymphocyte count and T-cell and B-cell subsets.
Asunto(s)
Síndromes de Inmunodeficiencia/diagnóstico , Diagnóstico Precoz , HumanosRESUMEN
A broad overview, with examples, of the potential pitfalls encountered in the clinical immunology laboratory is presented. Illustrative examples and case scenarios are provided from autoimmunity, immunochemistry and cellular immunology, looking at both technical and interpretative pitfalls.
Asunto(s)
Errores Diagnósticos , Pruebas Inmunológicas/normas , Adolescente , Adulto , Anciano de 80 o más Años , Anafilaxia/diagnóstico , Autoanticuerpos/análisis , Enfermedades Autoinmunes/diagnóstico , Niño , Femenino , Humanos , Pruebas Inmunológicas/métodos , Lactante , Masculino , Persona de Mediana Edad , Paraproteínas/análisis , Valor Predictivo de las Pruebas , Manejo de Especímenes/normas , Factores de TiempoRESUMEN
CAMPATH-1H (C-1H) is widely used in vivo and / or in vitro for T cell depletion in hematopoietic SCT. This humanised monoclonal antibody is specific for CD52, a marker coexpressed on the majority of human lymphocytes with CD48 and other glycosylphosphatidyl-inositol (GPI) anchored proteins. We detected CD52 / CD48 dual expression on >99% of CD3(+) lymphocytes from normal individuals and all 15 post-SCT patients whose transplants did not utilise C-1H. By contrast, 23 / 26 patients with transplants involving C-1H (in vivo, in vitro or both) exhibited populations lacking CD52 expression that accounted for 49.7% (4.2-86.2%) of the CD3+ lymphocytes (median and range) in samples evaluated at a median of 2 months post-SCT. Most CD52- cells also lacked CD48 expression. These GPI- T cells were of either donor or mixed donor / recipient origin. They were predominant in the early months after SCT at times of profound lymphopenia and inversely correlated with the recovery of the absolute lymphocyte count (r= - 0.663, P<0.0001). The presence of CD52- cells has been correlated previously with clinical outcome after CAMPATH therapy for both malignant and nonmalignant diseases.
Asunto(s)
Anticuerpos Monoclonales/química , Anticuerpos Antineoplásicos/química , Antineoplásicos/farmacología , Hemoglobinuria Paroxística/metabolismo , Linfocitos T/citología , Adolescente , Adulto , Alemtuzumab , Anticuerpos Monoclonales Humanizados , Antígenos CD/biosíntesis , Antígenos CD/química , Antígenos de Neoplasias/biosíntesis , Antígenos de Neoplasias/química , Complejo CD3/biosíntesis , Antígeno CD48 , Antígeno CD52 , Separación Celular , Niño , Preescolar , Estudios de Cohortes , Femenino , Citometría de Flujo , Glicoproteínas/biosíntesis , Glicoproteínas/química , Glicosilfosfatidilinositoles/metabolismo , Humanos , Separación Inmunomagnética , Masculino , Persona de Mediana Edad , Trasplante de Células Madre , Linfocitos T/metabolismo , Factores de Tiempo , Quimera por Trasplante , Trasplante Homólogo/métodos , Resultado del TratamientoRESUMEN
The rapid diagnosis of the t(15;17)(q22;q21) promyelocytic leukaemia is important in the early introduction of targeted therapy with all-trans retinoic acid plus chemotherapy. It has been noted that these are usually myeloperoxidase (MPO)-positive and HLA-DR-negative with homogenous expression of CD33 and heterogeneous expression of CD13. We evaluated the use of immunophenotyping, morphology and cytogenetics in our own practice. Cascade testing, using cytoplasmic MPO expression in a high percentage of blast cells in bone marrow as the primary screen and PML (promyelocytic leukaemia protein) expression as the secondary confirmatory test, allowed rapid identification of the cases with t(15;17). This approach allows early instigation of appropriate therapy.
Asunto(s)
Antígenos CD/inmunología , Antígenos de Diferenciación Mielomonocítica/inmunología , Antígenos CD13/inmunología , Antígenos HLA-DR/inmunología , Leucemia Promielocítica Aguda/diagnóstico , Leucemia Promielocítica Aguda/inmunología , Proteínas de Neoplasias/inmunología , Proteínas Nucleares/inmunología , Peroxidasa/inmunología , Factores de Transcripción/inmunología , Adulto , Médula Ósea/inmunología , Niño , Cromosomas Humanos Par 15/genética , Cromosomas Humanos Par 17/genética , Femenino , Humanos , Inmunofenotipificación , Hibridación Fluorescente in Situ , Cariotipificación , Leucemia Promielocítica Aguda/genética , Linfocitos/inmunología , Masculino , Proteína de la Leucemia Promielocítica , Lectina 3 Similar a Ig de Unión al Ácido Siálico , Translocación Genética/genética , Proteínas Supresoras de TumorRESUMEN
AIM: To determine the diagnostic efficiency of assays routinely used in the investigation of hereditary angio-oedema. METHODS: Over a four year period, 1144 samples were received for analysis from 907 patients suspected of C1 inhibitor deficiency. Analyses were performed for C4 and C1 inhibitor (functional and immunochemical). Notes were reviewed retrospectively on patients with low serological indicators to determine diagnosis. RESULTS: These are the first data to indicate the sensitivity, specificity, and predictive values of the assays most frequently used to screen for C1 inhibitor deficiency. A combination of low C4 and low C1 inhibitor function has 98% specificity for C1 inhibitor deficiency in this population and a 96% negative predictive value, and is thus a very effective screen. All patients with untreated C1 inhibitor deficiency had a low C4 value. CONCLUSIONS: All patients considered for a diagnosis of C1 inhibitor deficiency should have serum examined to measure both C4 and functional C1 inhibitor. If either is normal at presentation this essentially excludes a diagnosis of C1 inhibitor deficiency. These tests can be performed sequentially. If C4 is normal it is not necessary to proceed to C1 inhibitor analysis. If C1 inhibitor function and C4 are both low then a repeat sample should be obtained to confirm the findings.
Asunto(s)
Angioedema/diagnóstico , Proteínas Inactivadoras del Complemento 1/deficiencia , Proteínas Inactivadoras del Complemento 1/análisis , Complemento C4/análisis , Reacciones Falso Positivas , Humanos , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Sensibilidad y Especificidad , Pruebas Serológicas/métodosRESUMEN
A patient with a history of recurrent cutaneous and pulmonary infections, nephrotic syndrome, and an established diagnosis of type 1 diabetes was found to have unsuspected and unrecognised primary immunodeficiency. On review of the case, previous investigations pointed to the correct diagnosis over 10 years earlier. This combination of diagnoses has not previously been reported. The patient is now well on replacement intravenous immunoglobulin therapy, urinary loss of IgG having been specifically excluded before treatment. This case highlights how antibody deficiency can easily be missed despite an obvious infection history unless results are interpreted carefully and in context.