RESUMO
Human parvovirus B19 (B19V) causes myriads of clinical diseases; however, owing to lack of awareness and undetermined clinical impact, it has failed to become a virus pathogen of global concern. Cryptically, B19V causes significant morbidity and mortality. Half of the world population and 60 per cent of Indians are known to be serologically naive and are at risk of acquiring B19V infections. Cumulatively, our data showed 21.3 per cent B19V-infected patients with juvenile chronic arthropathy, recurrent abortions, multi-transfused thalassaemia and leukaemia. In addition, B19V-infected cases that ended fatally included patients with pure red cell aplasia, fulminant hepatitis and haemophagocytic syndrome. Novel clinical associations of B19V observed were amegakaryocytic thrombocytopaenia, myositis and non-occlusive ischaemic gangrene of bowel. B19V possesses multiple receptors which are distributed widely in human tissues. Vascular endothelial cell infection by B19V causes endothelialitis and vasculitic injuries besides antibody-dependent enhancement which empowered B19V to cause multiorgan diseases. Owing to lack of suitable animal model for B19V, true causal role remains to be determined, but numerous reports on B19V infections substantiate a causal role in multiorgan diseases. Hence, B19V infections need to be recognized, investigated and treated besides making efforts on vaccine developments.
RESUMO
La biopsia hepática de los aloinjertos sigue siendo considerada el estándar de oro y juega un papel importante e integral en la interpretación y explicación de los cambios que puedan ocurrir en respuesta a alteraciones en las pruebas de la función o bioquímica hepática, anomalías funcionales o alteración en las imágenes diagnósticas, las cuales pueden, o no, ir acompañadas de síntomas. También es útil en el seguimiento o biopsias por protocolo (1-3). La evaluación de biopsias, después del trasplante, puede ser difícil debido a que es muy amplio el espectro de las complicaciones que pueden presentarse en el período postrasplante; más aún, cuando muchas de ellas necesitan un diagnóstico y tratamiento inmediato. La patología más frecuente es el rechazo agudo. Sin embargo, también pueden observarse cambios de perfusión/reperfusión, alteraciones funcionales, recidiva de enfermedad de base, lesión de la vía biliar, lesiones vasculares, infecciones oportunistas, patologías de novo, como la hepatitis autoinmune, hepatitis crónica idiopática postrasplante, toxicidad farmacológica o tumores, entre otras patologías (4). En este artículo relacionado con la patología del trasplante hepático se tratarán las patologías más frecuentes, no quirúrgicas, en el período postrasplante temprano, con un enfoque histopatológico dirigido a las dificultades y controversias para una adecuada correlación clínico-patológica.
Biopsies of liver allografts are still considered to be the gold standard. They play an important and integral role in the interpretation and explanation of changes that may occur in response to alterations in function tests, in the interpretation and explanation of liver biochemistry, in the interpretation and explanation of functional abnormalities, and in the interpretation and explanation of diagnostic images (whether or not accompanied by symptoms). Biopsies are also useful for monitoring and are often part of the protocol (1-3). The evaluation of biopsy samples after transplantation can be difficult especially because of the very broad spectrum of complications that may arise in the post-transplant period. Many of them require immediate diagnosis and treatment despite this difficulty. Although the most common condition is acute rejection, many other conditions and disorders can be observed. They include perfusion/reperfusion alterations, functional impairment, recurrence of underlying diseases, injury to the bile duct, vascular lesions, opportunistic infections, de novo pathologies such as autoimmune hepatitis, post-transplant idiopathic chronic hepatitis, drug toxicity, and tumors (4). This is the second article about the pathology of liver transplantation. It discusses the most common pathologies in the early post-transplant period and provides a histopathological approach towards difficulties and controversies for adequate clinicopathological correlation.