Image-based modeling and scoring of Howell-Jolly Bodies in human erythrocytes.

The spleen selectively removes cells with intracellular inclusions, for example, detached nuclear fragments in circulating erythrocytes, called Howell-Jolly Bodies (HJBs). With absent or deficient splenic function HJBs appear in the peripheral blood and can be used as a simple and non-invasive risk-indicator for fulminant potentially life-threatening infection after spleenectomy. However, it is still under debate whether counting of the rare HJBs is a reliable measure of splenic function. Investigating HJBs in premature erythrocytes from patients during radioiodine therapy gives about 10 thousand times higher HJB counts than in blood smears. However, we show that there is still the risk of false-positive results by unspecific nuclear remnants in the prepared samples that do not originate from HJBs, but from cell debris residing above or below the cell. Therefore, we present a method to improve accuracy of image-based tests that can be performed even in non-specialized medical institutions. We show how to selectively label HJB-like clusters in human blood samples and how to only count those that are undoubtedly inside the cell. We found a "critical distance" dcrit referring to a relative HJB-Cell distance that true HJBs do not exceed. To rule out false-positive counts we present a simple inside-outside-rule based on dcrit -a robust threshold that can be easily assessed by combining conventional 2D imaging and straight-forward image analysis. Besides data based on fluorescence imaging, simulations of randomly distributed HJB-like objects on realistically modelled cell objects demonstrate the risk and impact of biased counting in conventional analysis. © 2017 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of ISAC.

Blood clearance of Howell-Jolly bodies in an experimental autogenic splenic implant model.

BACKGROUND: Autogenic splenic implant (ASI) is one of the few alternatives for preservation of splenic tissue when total splenectomy is inevitable. The aim of this study was to determine the morphological and functional regeneration of ASIs, as indicated by the clearance of Howell-Jolly (HJ) bodies, in an experimental model. METHODS: Ninety-nine male Wistar rats were divided into three groups: sham-operated (group 1), total splenectomy alone (group 2), and total splenectomy combined with ASI (group 3). Animals in group 3 were further allocated to nine subgroups of nine rats each, and analysed at different time points (1, 4, 8, 12, 16, 20, 24, 28 and 32 weeks after surgery). Blood smears were prepared at predetermined times for detection of HJ bodies. Morphological regeneration of tissue in the ASI was analysed by histology. RESULTS: At 1 week, the regenerated mass corresponded to about 7 per cent of the tissue implanted, reaching approximately 54 per cent at 24 weeks. The HJ body levels were increased in groups 2 and 3 until 8 weeks after surgery, following which levels in the ASI group became similar to those in the sham-operated group. HJ bodies were difficult to detect when a level of 22.5 per cent of regenerated ASI mass was reached. CONCLUSION: Functional regeneration of ASIs occurred from 8 weeks after surgery. When 22.5 per cent of regenerated ASI mass was reached almost no HJ bodies could be observed in the bloodstream, resembling a spleen in situ. SURGICAL RELEVANCE: Splenectomy has been practised routinely, both in the emergency setting and as a therapeutic elective procedure. There is a correlation between asplenia/hyposplenia and the occurrence of fulminant sepsis, underlining the importance of developing surgical methods for preserving splenic function. Both clinical and experimental studies have shown at least partial morphological and functional regeneration of autogenic splenic implants (ASIs). Experimental studies investigating the immunoprotective effect of ASIs, based mostly on exposure of animals to various bacteria, have demonstrated that ASIs can increase the rate of bacterial clearance and decrease mortality from sepsis. Clinical studies have shown their ability to remove colloidal substances and altered erythrocyte corpuscular inclusions, such as Howell-Jolly, Heinz and Pappenheimer bodies, from the bloodstream. In this experimental study the functional and morphological regeneration of ASIs was studied over time in rats.

Esquistossomose hepato-esplênica em crianças: corpúsculo de Howell-Jolly após esplenectomia e esplenose / Hepatosplenic schistosomiais mansoni in children: Howell-Jolly bodies after splenectomy and splenosis

A esquistossomose mansônica hepato-esplênica com varizes esofágicas é infrequente em crianças, entretanto, determina morbidade atingindo a produtividade desses futuros adultos. Há evidências de que a esplenose pós-esplenectomia, por trauma, mantém, de forma parcial, as funçSes imunológica e hemocaterética esplênicas. Estudos semelhantes, entretanto, nÝo foram realizados em esquistossomóticos submetidos a esplenectomia. Foram analisados, para avaliaçÝo da funçÝo de esplenose, 15 pacientes, de 7 a 18 anos, com esquistossomose hepato-esplênica submetidos a esplenectomia, ligadura de veia gástrica esquerda e auto-implante esplênico (Grupo A). A esplenose foi comprovada por cintilografia ou por Dopplerfluxometria. Também foram analisados cinco pacientes similares antes da cirurgia (grupo B) e três crianças, nÝo esquistossomóticas submetidas a esplenectomia sem auto-implante esplênico (grupo C). Os esfregaços de sangue periférico foram examinados para pesquisa de corpúsculos de Howell-Jolly, que indicam ausência ou insuficiência de funçÝo hemocaterética esplênica. Dos pacientes do grupo A, um (7por cento) apresentou corpúsculosde Howell-Jolly. Os demais nÝo apresentaram estes corpúsculos (93por cento). Nenhum paciente do grupo B os apresentou, enquanto que todos os esfregaços dos pacientes do Grupo C apresentaram estes corpúsculos. Os dados confirmam o auto-implante esplênico como método edicaz na manutençÝo da funçÝo hemocaterética esplênica