Interferencia positiva de las paraproteínas en la determinación de bilirrubina total y su rol en el diagnóstico de gammapatías monoclonales / Positive interference of paraproteins in the determination of total bilirubin and its role in the diagnosis of monoclonal gammopathies / Interferência positiva de paraproteínas na determinação da bilirrubina total e seu papel no diagnóstico de gamopatias monoclonais

Resumen La interferencia por paraproteínas en los análisis clínicos ha sido extensamente informada a nivel mundial. Si bien se han propuesto estrategias metodológicas para evitar el informe de datos erróneos asociados a interferencias (p. ej. confirmación manual, sistema de alerta), en pocos casos se ha propuesto su detección como herramienta diagnóstica de patologías no sospechadas desde la clínica. A partir del trabajo conjunto de dos hospitales de la provincia de Buenos Aires se describió: i) la presencia de interferencia positiva de paraproteínas en la determinación de bilirrubina total con reactivos y autoanalizadores Wiener, y ii) su contribución, en un período inferior a los seis meses, a la detección de cuatro gammapatías no sospechadas (tres monoclonales). Se recomienda dar difusión de esta inferencia a nivel nacional y se propone un esquema de trabajo en laboratorio para identificar la interferencia así como un perfil mínimo de determinaciones para evaluar la existencia de gammapatías desconocidas.

Abstract Paraprotein interference in clinical biochemistry has been widely reported around the world. Methodological strategies have been proposed to avoid reporting erroneous data due to interferences (i.e. manual check, alert system); however, few cases have suggested its use as a diagnostic tool for unsuspected pathologies. Based on the joint work of two hospitals from Buenos Aires Province, the following has been described: i) the presence of positive interference of paraproteins in the assessment of total bilirubin with Wiener chemistry and autoanalizers, and ii) its contribution, in less than six months, to the diagnosis of four gammophaties previously unsuspected (three monoclonal ones). Sharing the occurrence of this interference in our country is recommended. An interference identification workflow is also propose, as well as a set of biochemical assays to evaluate the occurrence of unsuspected gammophaties.

Resumo A interferência da paraproteína na bioquímica clínica tem sido amplamente relatada em todo o mundo. Embora estratégias metodológicas para evitar a comunicação de dados errôneos associados a interferências tenham sido propostas (p. ex., verificação manual, sistema de alerta), em poucos casos sugerem seu uso como ferramenta diagnóstica para patologias não suspeitas a partir da clínica. Com base no trabalho conjunto de dois hospitais da Província de Buenos Aires, foi descrita: i) a presença de interferência positiva de paraproteínas na determinação da bilirrubina total com reagentes e autoanalisadores Wiener e ii) sua contribuição, em um período inferior aos seis meses, para o diagnóstico de quatro gamopatias não suspeitas (três monoclonais). Recomenda-se difundir essa interferência em nível nacional e se propõe um esquema de trabalho em laboratório para identificar a interferência bem como um perfil mínimo de determinações para avaliar a ocorrência de gamopatias desconhecidas.

Treatment of idiopathic light chain deposition disease: complete remission with bortezomib and dexamethasone / Tratamento da doença de depósito de cadeia leve idiopática: remissão completa com bortezomib e dexametasona

Abstract Light chain deposition disease (LCDD) is a rare clinical entity characterized by the deposition of light chain immunoglobulins in different tissues and primarily affects the kidneys, followed by the liver and heart. This disease often manifests as nephrotic syndrome with marked proteinuria and rapid deterioration of renal function. More than 50% of cases are secondary to multiple myeloma or other lymphoproliferative diseases, with a well-established treatment aimed at controlling the underlying disease. In rare cases, there is no detection of an associated hematological disease, referred to as idiopathic LCDD. In these cases, there is no evidence-based consensus on the therapeutic approach, and management is based on the clinical experience of reported cases. Here we report a case of idiopathic LCDD treated with bortezomib and dexamethasone with complete hematologic responses, significant reduction of proteinuria, and improved renal function.

Resumo A doença de deposição de cadeia leve (DDCL) é uma entidade clínica rara caracterizada pela deposição de cadeias leves das imunoglobulinas em diferentes tecidos e afeta principalmente os rins, seguido pelo fígado e coração. Manifesta-se frequentemente como síndrome nefrótica com proteinúria marcante e rápida deterioração da função renal. Mais de 50% dos casos são secundários ao mieloma múltiplo ou outras doenças linfoproliferativas, tendo seu tratamento bem estabelecido, voltado para o controle da doença de base. Em casos raros, não há detecção de uma doença hematológica associada, sendo referida como DDCL idiopática. Nestes casos, não há um consenso baseado em evidências sobre a abordagem terapêutica, tendo sua conduta baseada na experiência clínica dos casos relatados. Aqui, nós relatamos um caso de DDCL idiopática tratado com bortezomib e dexametasona atingindo resposta hematológica completa, redução significativa da proteinúria e recuperação da função renal.

Sospecha diagnóstica de mieloma múltiple en atención primaria: reporte de un caso / Multiple myeloma suspected in primary care: case report

Introducción: El mieloma múltiple (MM) es una neoplasia hematológica caracterizada por una proliferación clonal de células plasmáticas que genera una disfunción multiorgánica, con daño a nivel óseo, siendo una importante causa de morbimortalidad en estos pacientes. Presentación del caso: Mujer de 69 años, hipertensa tratándose con enalapril hace 10 años, operada de un prolapso genital en el año 2015, con antecedentes de fallecimiento de un hijo a los 30 años por un cáncer no especificado, refirió cuadro de un año de evolución caracterizado por oligoartralgias en extremidades inferiores, con predominio derecho, además de baja de peso de aproximadamente 5 kg en 4 meses. En atención primaria se solicitó exámenes que revelaron anemia moderada normocítica-normocrómica y velocidad de eritrosedimentación de 125 mm/hora, por lo cual, se derivó a Hospital de Puerto Montt. Durante hospitalización, se realizó biopsia de médula ósea que informó células plasmáticas que representaban más del 90% de los elementos medulares evaluables. Electroforesis de proteínas en sangre destacó banda de aspecto monoclonal en zona gamma de 7.9 g/dl. Frotis de eritrocitos con rouleaux positivo, proteínas totales de 13.1 g/dl y calcio corregido de 10.6 mg/dl. Se confirmó MM, iniciándose tratamiento con talidomida, melfalán y prednisona, además de bifosfonato y analgesia, con controles mensuales en policlínico de Hematología. Discusión: El MM es una enfermedad incurable, por ello el diagnóstico precoz en atención primaria es fundamental para dirigir los esfuerzos terapéuticos hacia la remisión de la enfermedad y mejoría de la calidad de vida.

ntroduction: Multiple myeloma (MM) is a hematological neoplasm characterized by clonal proliferation of plasma cells that generates multiple organ dysfunction, with bone damage, which it's an important cause of mortality in these patients. Case report: F69 year old woman with hypertension treated with enalapril from 10 years ago, with history of a genital prolapse surgery in 2015, and refers the death of a 30 years old son for an unspecified cancer. She had a 1 year evolution of symptoms characterized by oligoartralgias in lower extremities, predominantly right, in addition to 5 kg weight loss in 4 months. In Primary Care tests were requested, showing: moderate anemia normocytic- normocromic, erythrocyte sedimentation rate 125 mm/hour. Then, she was referred to Hospital of Puerto Montt to complete the study. Hospitalized, bone marrow biopsy was performed and showed more tan 90% of plasma cells. Blood protein electrophoresis, showed monoclonal band in gamma zone of 7.9 g/dl. Smears erythrocyte rouleaux positive, measurement of total proteins of 13.1 g/dl, corrected calcium of 10.6 mg/dl. MM suspicion was confirmed, starting treatment with thali-domide, melphalan and prednisone plus bisphosphonate and analgesia, with monthly checks of hematology polyclinic. Discussion: The MM is an incurable disease, so early diagnosis in Primary Care is essential to direct therapeutic efforts toward disease remission and improved quality of life.

Biclonal gammopathies: Retrospective study of 47 patients. / Gammapatías biclonales: estudio retrospectivo de 47 pacientes.

OBJECTIVES: Biclonal gammopathies are characterized by the clonal proliferation of plasma cells or their B-lymphoid progenitors and are associated with the production of abnormal immunoglobulins (M proteins or paraproteins). There are no known studies that have analyzed this disease in Spain. We studied the underlying diseases, characteristics of paraproteins and the evolution of a series of patients with biclonal gammopathy. MATERIAL AND METHODS: We reviewed clonal gammopathies at the Department of Immunology of Hospital Puerta de Hierro in Madrid, between 1970 and 2011, selecting those patients with biclonal gammopathy in one reading. We collected data on the patient's epidemiology, underlying disease, associated diseases, therapies and paraprotein and immunoglobulin levels. RESULTS: Of the 1626 cases of clonal gammapathies, 47 were biclonal gammopathy (2.89%). The median follow-up was 2 years. The main associated condition was biclonal gammopathies of undetermined significance (BGUS). The most common paraprotein combination was IgG-IgG. Upon conducting a second paraprotein reading, 81% of the patients had lost at least 1 monoclonal component. A third of the patients had not undergone treatment. CONCLUSIONS: Biclonal gammopathy are fundamentally associated with biclonal gammopathies of undetermined significance. No biclonal gammopathies of undetermined significance evolved to a malignant disease. In a high percentage of patients, at least 1 of the 2 clonal components disappeared, sometimes spontaneously.