Splenic function: normal, too much and too little

Splenic filtration of red blood cells in physiology, malaria and sickle cell disease

PURPOSE OF REVIEW

The human spleen clears the blood from circulating microorganisms and red blood cells (RBCs) displaying alterations. This review analyzes how generic mechanisms by which the spleen senses RBC, such pitting, trapping and erythrophagocytosis, impact the pathogenesis of two major spleen-related diseases, malaria and sickle cell disease (SCD).

RECENT FINDINGS

Scintigraphy, functional histology, comparison of circulating and splenic RBC, ex-vivo perfusion of human spleens and in-silico modeling enable relevant exploration of how the spleen retains and processes RBC in health and disease. Iterative cross-validations between medical observations, in-vitro experiments and in-silico modeling point to mechanical sensing of RBC as a central event in both conditions. Spleen congestion is a common pathogenic process explaining anemia and splenomegaly, the latter carrying a risk of severe complications such as acute splenic sequestration crisis and hypersplenism in SCD. Sickling of hemoglobin S-containing RBC may contribute to these complications without necessarily being the trigger.

SUMMARY

Ongoing progress in the exploration and understanding of spleen-related complications in malaria and SCD open the way to optimized prognosis evaluation and therapeutic applications.

Enhancing in vivo cell and tissue targeting by modulation of polymer nanoparticles and macrophage decoys

The in vivo efficacy of polymeric nanoparticles (NPs) is dependent on their pharmacokinetics, including time in circulation and tissue tropism. Here we explore the structure-function relationships guiding physiological fate of a library of poly(amine-co-ester) (PACE) NPs with different compositions and surface properties. We find that circulation half-life as well as tissue and cell-type tropism is dependent on polymer chemistry, vehicle characteristics, dosing, and strategic co-administration of distribution modifiers, suggesting that physiological fate can be optimized by adjusting these parameters. Our high-throughput quantitative microscopy-based platform to measure the concentration of nanomedicines in the blood combined with detailed biodistribution assessments and pharmacokinetic modeling provides valuable insight into the dynamic in vivo behavior of these polymer NPs. Our results suggest that PACE NPs-and perhaps other NPs-can be designed with tunable properties to achieve desired tissue tropism for the in vivo delivery of nucleic acid therapeutics. These findings can guide the rational design of more effective nucleic acid delivery vehicles for in vivo applications.

The protective effect of the spleen in sickle cell patients. A comparative study between patients with asplenia/hyposplenism and hypersplenism

Sickle cell disease (SCD) is caused by a point mutation in the beta-globin gene. SCD is characterized by chronic hemolytic anemia, vaso-occlusive events leading to tissue ischemia, and progressive organ failure. Chronic inflammatory state is part of the pathophysiology of SCD. Patients with SCD have extremely variable phenotypes, from mild disease to severe complications including early age death. The spleen is commonly injured in SCD. Early splenic dysfunction and progressive spleen atrophy are common. Splenomegaly and hypersplenism can also occur with the loss of the crucial splenic function. Acute, life-threatening spleen-related complications in SCD are well studied. The association of laboratory parameters with the spleen status including hyposplenism, asplenia, and splenomegaly/hypersplenism, and their implication in vaso-occlusive crisis and long-term complications in SCD remain to be determined. We evaluated the association between the spleen status with clinical and laboratory parameters in 31 SCD patients: Group a) Patients with asplenia/hyposplenism (N = 22) (including auto-splenectomy and splenectomized patients) vs. Group b) patients with splenomegaly and or hypersplenism (N = 9). Laboratory studies included: Complete Blood Count, reticulocyte count, iron metabolism parameters, C Reactive Protein (CRP), Hb variant distribution, and D-dimer. Metabolic and morphological red blood cell (RBC) studies included: density gradient (by Percoll), glucose consumption, lactate release, and K⁺ leakage, fetal RBC (F-Cells) and F-Reticulocytes, annexinV+, CD71⁺, oxidative stress measured by GSH presence in RBC and finally Howell Jolly Bodies count were all analyzed by Flow Cytometry. Scanning electron microscopy analysis of RBC was also performed. Patients with asplenia/hyposplenism showed significantly higher WBC, platelet, Hematocrit, hemoglobin S, CRP, D-dimer, Gamma Glutamyl Transferase (GGT), cholesterol, transferrin, annexin V+ RBCs, CD71⁺ RBCs, together with a markedly lower F Reticulocyte levels in comparison with splenomegaly/hypersplenism patients. In summary, important differences were also found between the groups in the studied RBCs parameters. Further studies are required to elucidate the effect of the spleen including hyper and hypo-splenia on laboratory parameters and in clinical manifestations, vascular pathology, and long-term complications of SCD. The benefits and risks of splenectomy compared to chronic transfusion need to be evaluated in clinical trials and the standard approach managing hypersplenism in SCD patients should be re-evaluated.

Insights from the use of erythropoietin in experimental Chagas disease

In addition to the long-established role in erythropoiesis, erythropoietin (Epo) has protective functions in a variety of tissues, including the heart. This is the most affected organ in chronic Chagas disease, caused by the protozoan Trypanosoma cruzi. Despite seven million people being infected with T. cruzi worldwide, there is no effective treatment preventing the disease progression to the chronic phase when the pathological involvement of the heart is often observed. Chronic chagasic cardiomyopathy has a wide variety of manifestations, like left ventricular systolic dysfunction, dilated cardiomyopathy, and heart failure. Since Epo may help maintain cardiac function by reducing myocardial necrosis, inflammation, and fibrosis, this study aimed to evaluate whether the Epo has positive effects on experimental Chagas disease. For that, we assessed the earlier (acute phase) and also the later (chronic phase) use of Epo in infected C57BL/6 mice. Blood cell count, biochemical parameters, parasitic load, and echocardiography data were evaluated. In addition, histopathological analysis was carried out. Our data showed that Epo had no trypanocide effect nor did it modify the production of anti-T. cruzi antibodies. Epo-treated groups exhibited parasitic burden much lower in the heart compared to blood. No pattern of hematological changes was observed combining infection with treatment with Epo. Chronic Epo administration reduced CK-MB serum activity from d0 to d180, irrespectively of T. cruzi infection. Likewise, echocardiography and histological results indicate that Epo treatment is more effective in the chronic phase of experimental Chagas disease. Since treatment is one of the greatest challenges of Chagas disease, alternative therapies should be investigated, including Epo combined with benznidazole.

High-fat diet activates splenic NOD1 and enhances neutrophil recruitment and neutrophil extracellular traps release in the spleen of ApoE-deficient mice

In the course of atherogenesis, the spleen plays an important role in the regulation of extramedullary hematopoiesis, and in the control of circulating immune cells, which contributes to plaque progression. Here, we have investigated the role of splenic nucleotide-binding oligomerization domain 1 (NOD1) in the recruitment of circulating immune cells, as well as the involvement of this immune organ in extramedullary hematopoiesis in mice fed on a high-fat high-cholesterol diet (HFD). Under HFD conditions, the absence of NOD1 enhances the mobilization of immune cells, mainly neutrophils, from the bone marrow to the blood. To determine the effect of NOD1-dependent mobilization of immune cells under pro-atherogenic conditions, Apoe^−/− and Apoe^−/−Nod1^−/− mice fed on HFD for 4 weeks were used. Splenic NOD1 from Apoe^−/− mice was activated after feeding HFD as inferred by the phosphorylation of the NOD1 downstream targets RIPK2 and TAK1. Moreover, this activation was accompanied by the release of neutrophil extracellular traps (NETs), as determined by the increase in the expression of peptidyl arginine deiminase 4, and the identification of citrullinated histone H3 in this organ. This formation of NETs was significantly reduced in Apoe^−/−Nod1^−/− mice. Indeed, the presence of Ly6G⁺ cells and the lipidic content in the spleen of mice deficient in Apoe and Nod1 was reduced when compared to the Apoe^−/− counterparts, which suggests that the mobilization and activation of circulating immune cells are altered in the absence of NOD1. Furthermore, confirming previous studies, Apoe^−/−Nod1^−/− mice showed a reduced atherogenic disease, and diminished recruitment of neutrophils in the spleen, compared to Apoe^−/− mice. However, splenic artery ligation reduced the atherogenic burden in Apoe^−/− mice an effect that, unexpectedly was lost in Apoe^−/−Nod1^−/− mice. Together, these results suggest that neutrophil accumulation and activity in the spleen are driven in part by NOD1 activation in mice fed on HFD, contributing in this way to regulating atherogenic progression.

Corrected cerebral blood flow and reduced cerebral inflammation in berk sickle mice with higher fetal hemoglobin

Fetal hemoglobin (HbF) is known to lessen the severity of sickle cell disease (SCD), through reductions in peripheral vaso-occlusive disease and reduced risk for cerebrovascular events. However, the influence of HbF on oxygen delivery to high metabolism tissues like the brain, or its influence on cerebral perfusion, metabolism, inflammation or function have not been widely studied. We employed a Berkley mouse model (BERK) of SCD with gamma transgenes q3 expressing exclusively human α- and β^S-globins with varying levels of γ globin expression to investigate the effect of HbF expression on the brain using magnetic resonance imaging (MRI), MRI diffusion tensor imaging (DTI) and spectroscopy (MRS) and hematological parameters. Hematological parameters improved with increasing γ level expression, as did markers for brain metabolism, perfusion and inflammation. Brain microstructure assessed by DTI fractional anisotropy improved, while myo-inositol levels increased, suggesting improved microstructural integrity and reduced cell loss. Our results suggest that increasing γ levels not only improves sickle peripheral disease, but also improves brain perfusion and oxygen delivery while reducing brain inflammation while protecting brain microstructural integrity.

To evaluate the effect of small-group demonstration-based training module in improving clinical skills in undergraduate medical students

BACKGROUND

In today's modern era, the two most important aspects of medical education are evaluation- and outcome-based learning. Directly Observed Procedural Skills (DOPSs ) is a well-known method of evaluation which constitutes a direct observation of the practical skills being performed by the student and simultaneous written feedback by the teacher.

METHOD

A total of 40 undergraduate students were taught by a module based on DOPS. A pre-test and post-test was conducted on DOPS examination pattern and was compared by the Cochran's Q test.

RESULTS

In this study, a total of 40 medical undergraduate students and 10 teachers participated. Each student was given one pre-test and five post-test with ultrasound proven mild to moderate splenomegaly. Each student was individually assessed on a module based on DOPS and was given direct feedback by the teachers. A total of 34 (85%) students strongly agreed that they felt comfortable and confident with this methodology.

CONCLUSION

The results of this study revealed that DOPS tests can be used as an effective evaluation method to assess medical students because of its appropriate validity and reliability, positive impact on learning, and high satisfaction level amongst students. However, special attention needs to be given to the quality of these tests.

Contribution of Extramedullary Hematopoiesis to Atherosclerosis. The Spleen as a Neglected Hub of Inflammatory Cells

Cardiovascular diseases (CVDs) incidence is becoming higher. This fact is promoted by metabolic disorders such as obesity, and aging. Atherosclerosis is the underlying cause of most of these pathologies. It is a chronic inflammatory disease that begins with the progressive accumulation of lipids and fibrotic materials in the blood-vessel wall, which leads to massive leukocyte recruitment. Rupture of the fibrous cap of the atherogenic cusps is responsible for tissue ischemic events, among them myocardial infarction. Extramedullary hematopoiesis (EMH), or blood cell production outside the bone marrow (BM), occurs when the normal production of these cells is impaired (chronic hematological and genetic disorders, leukemia, etc.) or is altered by metabolic disorders, such as hypercholesterolemia, or after myocardial infarction. Recent studies indicate that the main EMH tissues (spleen, liver, adipose and lymph nodes) complement the hematopoietic function of the BM, producing circulating inflammatory cells that infiltrate into the atheroma. Indeed, the spleen, which is a secondary lymphopoietic organ with high metabolic activity, contains a reservoir of myeloid progenitors and monocytes, constituting an important source of inflammatory cells to the atherosclerotic lesion. Furthermore, the spleen also plays an important role in lipid homeostasis and immune-cell selection. Interestingly, clinical evidence from splenectomized subjects shows that they are more susceptible to developing pathologies, such as dyslipidemia and atherosclerosis due to the loss of immune selection. Although CVDs represent the leading cause of death worldwide, the mechanisms involving the spleen-atherosclerosis-heart axis cross-talk remain poorly characterized.

Complications in the adult asplenic patient: A review for the emergency clinician

BACKGROUND

The spleen performs several important physiologic functions. However, patients can have functional asplenia or have their spleen removed for a number of reasons, which can put them at risk for several dangerous complications.

OBJECTIVE

This narrative review provides a focused evaluation of adult asplenic patients and complications in the emergency departing setting.

DISCUSSION

The spleen plays integral roles in the immune and reticuloendothelial systems and also modulates the inflammatory and coagulation cascades. Asplenia refers to the anatomic or physiologic loss of splenic function, which may be due to trauma, immunological, hematological, or oncological etiologies. Asplenic patients are at risk for several complications including infection, arterial and venous thrombosis, and pulmonary hypertension. Fever in an asplenic patient and overwhelming post-splenectomy infection (OPSI) are medical emergencies with a high mortality and require rapid evaluation and management with broad-spectrum antibiotics. Asplenic patients are at increased risk of arterial thrombosis, such as coronary artery disease, and venous thrombosis including deep venous thrombosis, pulmonary embolism, and splenic and portal vein thrombosis. Management of venous thrombosis includes anticoagulation. Pulmonary hypertension with associated right ventricular dysfunction may also occur in asplenia. These patients require hemodynamic stabilization with an emphasis on inciting causes and treatment of the pulmonary hypertension.

CONCLUSIONS

The spleen is an integral organ involved in several physiologic functions. Asplenia, or absence of spleen function, is associated with severe complications. Knowledge of these complications can improve the care of these patients.

Outcomes after splenectomy in children: a 48-year population-based study

PURPOSE

In children who have undergone splenectomy, there may be impaired immunologic function and an increased risk of infection. We aimed to define the long-term rate of and risk factors for post-splenectomy infection using a population-based cohort study.

METHODS

All children (< 18 years) who underwent splenectomy from 1966 to 2011 in Olmsted County, MN were identified using the Rochester Epidemiology Project (REP). Descriptive statistics, Kaplan-Meier estimates, and Cox Proportional hazard ratios were performed to evaluate for risk factors associated with developing infection.

RESULTS

Ninety patients underwent splenectomy and 46% were female. Indications included trauma (42%), benign hematologic disease (33%), malignancy (13%), and other (11%). Most were performed open. Vaccination was completed in (72%) for pneumococcal, H. influenza, and meningococcal vectors. Nineteen patients developed infection, and associated factors included non-traumatic, non-malignant disease [HR 4.83 (1.18-19.85)], and performance of multiple surgical procedures [HR 2.80 (1.09-7.21)]. Estimated survival free of infection rates at 15 and 20 years following surgery was both 97%.

CONCLUSIONS

After splenectomy in children, most patients do not develop infection. Nearly three-quarters of patients were vaccinated with the lowest rates in patients that underwent a splenectomy for trauma. In patients who received multiple procedures during a splenectomy, the infection risk was higher.

Correlation between the values of circulating blood elements with the size of spleen in the presence of schistosomal splenomegaly

PURPOSE

To evaluate a possible relationship between the size of the spleen and values of circulating blood elements in patients with schistosomatic splenomegaly.

METHODS

ixty one patients with hepatosplenic schistosomiasis mansoni underwent a clinical exam and peripheral venous blood was collected for a hemogram. The erythrocyte, hemoglobin, hematocrit, leukocyte, and platelet values were determined. All patients underwent abdominal ultrasound to measure the spleen. The hematological test results were compared to the size of the spleen.

RESULTS

The size of the spleen varied from 14.0 to 28.4 (19.9 ± 3.7) cm according to the ultrasound image. Thrombocytopenia was observed 58 (95%) patients, leukopenia in 55 (90%) patients, and anemia in 32 (52.4%) patients. Leukopenia was proportional to splenomegaly.

CONCLUSION

Schistosomal splenomegaly leads to leukopenia in direct proportion to the size of the spleen.

Robust Multicontrast MRI Spleen Segmentation for Splenomegaly Using Multi-Atlas Segmentation

OBJECTIVE

Magnetic resonance imaging (MRI) is an essential imaging modality in noninvasive splenomegaly diagnosis. However, it is challenging to achieve spleen volume measurement from three-dimensional MRI given the diverse structural variations of human abdomens as well as the wide variety of clinical MRI acquisition schemes. Multi-atlas segmentation (MAS) approaches have been widely used and validated to handle heterogeneous anatomical scenarios. In this paper, we propose to use MAS for clinical MRI spleen segmentation for splenomegaly.

METHODS

First, an automated segmentation method using the selective and iterative method for performance level estimation (SIMPLE) atlas selection is used to address the concerns of inhomogeneity for clinical splenomegaly MRI. Then, to further control outliers, semiautomated craniocaudal spleen length-based SIMPLE atlas selection (L-SIMPLE) is proposed to integrate a spatial prior in a Bayesian fashion and guide iterative atlas selection. Last, a graph cuts refinement is employed to achieve the final segmentation from the probability maps from MAS.

RESULTS

A clinical cohort of 55 MRI volumes (28 T1 weighted and 27 T2 weighted) was used to evaluate both automated and semiautomated methods.

CONCLUSION

The results demonstrated that both methods achieved median Dice , and outliers were alleviated by the L-SIMPLE (≍1 min manual efforts per scan), which achieved 0.97 Pearson correlation of volume measurements with the manual segmentation.

SIGNIFICANCE

In this paper, spleen segmentation on MRI splenomegaly using MAS has been performed.

Relationship between response to lusutrombopag and splenic volume

AIM

To assess the correlation between the efficacy of lusutrombopag and clinical characteristics in patients with chronic liver disease.

METHODS

In this retrospective, multicenter study, which conducted at four locations in Japan, 50 thrombocytopenic patients with chronic liver disease were enrolled. All patients received oral lusutrombopag (3.0 mg/d for 7 d) for chronic liver disease. We assessed the increase in platelet count after the trial drug administration. A treatment response was defined as a platelet count ≥ 5 × 104/μL and an increased platelet count ≥ 2 × 104/μL from baseline after drug administration. We evaluated the response to lusutrombopag compared to baseline clinical characteristics in patients with chronic liver disease.

RESULTS

The numbers of responders and non-responders were 40 (80.0%) and 10 (20.0%), respectively. The patients were divided into a responder and non-responder group, and we added factors that may correspond to successful treatment with lusutrombopag. Splenic volume and body weight were lower in the responder group than in the non-responder group. White blood cell count and hemoglobin level were higher in responders compared with non-responders. Using a logistic regression model to assess the relationship between response to lusutrombopag and clinical characteristics, multivariate analysis confirmed that splenic volume was an independent factor that predicted the response of platelet counts (P = 0.025; odds ratio = 11.2; 95% confidence interval: 1.354-103.0). Splenic volume negatively correlated to changes in platelet count (r = -0.524, P = 0.001).

CONCLUSION

Splenic volume influences the change in platelet counts after administration of lusutrombopag in patients with chronic liver disease.

Splenomegaly Segmentation using Global Convolutional Kernels and Conditional Generative Adversarial Networks

Spleen volume estimation using automated image segmentation technique may be used to detect splenomegaly (abnormally enlarged spleen) on Magnetic Resonance Imaging (MRI) scans. In recent years, Deep Convolutional Neural Networks (DCNN) segmentation methods have demonstrated advantages for abdominal organ segmentation. However, variations in both size and shape of the spleen on MRI images may result in large false positive and false negative labeling when deploying DCNN based methods. In this paper, we propose the Splenomegaly Segmentation Network (SSNet) to address spatial variations when segmenting extraordinarily large spleens. SSNet was designed based on the framework of image-to-image conditional generative adversarial networks (cGAN). Specifically, the Global Convolutional Network (GCN) was used as the generator to reduce false negatives, while the Markovian discriminator (PatchGAN) was used to alleviate false positives. A cohort of clinically acquired 3D MRI scans (both T1 weighted and T2 weighted) from patients with splenomegaly were used to train and test the networks. The experimental results demonstrated that a mean Dice coefficient of 0.9260 and a median Dice coefficient of 0.9262 using SSNet on independently tested MRI volumes of patients with splenomegaly.

Physiological, but not fitness, effects of two interacting haemoparasitic infections in a wild rodent

In contrast to the conditions in most laboratory studies, wild animals are routinely challenged by multiple infections simultaneously, and these infections can interact in complex ways. This means that the impact of a parasite on its host's physiology and fitness cannot be fully assessed in isolation, and requires consideration of the interactions with other co-infections. Here we examine the impact of two common blood parasites in the field vole (Microtus agrestis): Babesia microti and Bartonella spp., both of which have zoonotic potential. We collected longitudinal and cross-sectional data from four populations of individually tagged wild field voles. This included data on biometrics, life history, ectoparasite counts, presence/absence of microparasites, immune markers and, for a subset of voles, more detailed physiological and immunological measurements. This allowed us to monitor infections over time and to estimate components of survival and fecundity. We confirm, as reported previously, that B. microti has a preventative effect on infection with Bartonella spp., but that the reverse is not true. We observed gross splenomegaly following B. microti infection, and an increase in IL-10 production together with some weight loss following Bartonella spp. infection. However, these animals appeared otherwise healthy and we detected no impact of infection on survival or fecundity due to the two haemoparasite taxa. This is particularly remarkable in the case of B. microti which induces apparently drastic long-term changes to spleen sizes, but without major adverse effects. Our work sheds light on the ecologies of these important zoonotic agents, and more generally on the influence that interactions among multiple parasites have on their hosts in the wild.

Multi-atlas Segmentation Enables Robust Multi-contrast MRI Spleen Segmentation for Splenomegaly

Non-invasive spleen volume estimation is essential in detecting splenomegaly. Magnetic resonance imaging (MRI) has been used to facilitate splenomegaly diagnosis in vivo. However, achieving accurate spleen volume estimation from MR images is challenging given the great inter-subject variance of human abdomens and wide variety of clinical images/modalities. Multi-atlas segmentation has been shown to be a promising approach to handle heterogeneous data and difficult anatomical scenarios. In this paper, we propose to use multi-atlas segmentation frameworks for MRI spleen segmentation for splenomegaly. To the best of our knowledge, this is the first work that integrates multi-atlas segmentation for splenomegaly as seen on MRI. To address the particular concerns of spleen MRI, automated and novel semi-automated atlas selection approaches are introduced. The automated approach interactively selects a subset of atlases using selective and iterative method for performance level estimation (SIMPLE) approach. To further control the outliers, semi-automated craniocaudal length based SIMPLE atlas selection (L-SIMPLE) is proposed to introduce a spatial prior in a fashion to guide the iterative atlas selection. A dataset from a clinical trial containing 55 MRI volumes (28 T1 weighted and 27 T2 weighted) was used to evaluate different methods. Both automated and semi-automated methods achieved median DSC > 0.9. The outliers were alleviated by the L-SIMPLE (≈1 min manual efforts per scan), which achieved 0.9713 Pearson correlation compared with the manual segmentation. The results demonstrated that the multi-atlas segmentation is able to achieve accurate spleen segmentation from the multi-contrast splenomegaly MRI scans.

MDP: A Deinococcus Mn2+-Decapeptide Complex Protects Mice from Ionizing Radiation

The radioprotective capacity of a rationally-designed Mn²⁺-decapeptide complex (MDP), based on Mn antioxidants in the bacterium Deinococcus radiodurans, was investigated in a mouse model of radiation injury. MDP was previously reported to be extraordinarily radioprotective of proteins in the setting of vaccine development. The peptide-component (DEHGTAVMLK) of MDP applied here was selected from a group of synthetic peptides screened in vitro for their ability to protect cultured human cells and purified enzymes from extreme damage caused by ionizing radiation (IR). We show that the peptides accumulated in Jurkat T-cells and protected them from 100 Gy. MDP preserved the activity of T4 DNA ligase exposed to 60,000 Gy. In vivo, MDP was nontoxic and protected B6D2F1/J (female) mice from acute radiation syndrome. All irradiated mice treated with MDP survived exposure to 9.5 Gy (LD_70/30) in comparison to the untreated mice, which displayed 63% lethality after 30 days. Our results show that MDP provides early protection of white blood cells, and attenuates IR-induced damage to bone marrow and hematopoietic stem cells via G-CSF and GM-CSF modulation. Moreover, MDP mediated the immunomodulation of several cytokine concentrations in serum including G-CSF, GM-CSF, IL-3 and IL-10 during early recovery. Our results present the necessary prelude for future efforts towards clinical application of MDP as a promising IR countermeasure. Further investigation of MDP as a pre-exposure prophylactic and post-exposure therapeutic in radiotherapy and radiation emergencies is warranted.

In vivo biodistribution and toxicity of Gd2O3:Eu3+ nanotubes in mice after intraperitoneal injection

To better understand the potential impact of Gd₂O₃:Eu³⁺ nanotubes on human health, we investigated their biodistribution, subacute toxicity, and hepatic injury in mice under different dosages (4.0, 40.0, and 400.0 mg kg⁻¹).

Functional hyposplenism is an important and underdiagnosed immunodeficiency condition in children

AIM

Few studies have focused on paediatric hyposplenism/asplenism, in which splenic phagocytic activity is diminished or absent in an anatomically present spleen. This study aimed to evaluate clinical findings, laboratory tests and prognosis of children with functional hyposplenism/asplenism.

METHODS

The study group comprised 74 children who had liver/spleen technetium-99m sulphur colloid scintigraphy from 2002 to 2008. Information collected included demographic features, background diseases, blood smear findings, indications for scintigraphy and outcome. Children with functional hyposplenism were followed until 2012.

RESULTS

We found that 34 patients had functional hyposplenism/asplenism. The main indications for scintigraphy in the hyposplenic patients were persistent thrombocytosis and recurrent infections. Associated conditions included immunodeficiencies, autoimmune diseases, malignancies and genetic disorders. Main infections were sinopulmonary infections, bacteraemia and sepsis. The major pathogens were Streptococcus pneumoniae and Haemophilus influenza group A. There was no correlation between the presence of Howell-Jolly bodies in blood smear with clinical disease severity or scintigraphic findings. Repeated scintigraphy showed spontaneous normalisation in 40% of patients.

CONCLUSION

Functional hyposplenism is an important and underdiagnosed immunodeficiency condition in children, associated with various clinical conditions including prolonged unexplained thrombocytosis, immune deficiency and autoimmunity. Technetium-99m sulphur colloid scintigraphy is the method of choice for evaluating splenic function.

Postsplenectomy left lower lobe bronchiectasis

BACKGROUND

Bronchiectasis has decreased significantly. I describe a new underestimated clinicopathological entity of postsplenectomy left lower lobe bronchiectasis.

METHODS

This is a retrospective study on 24 patients who had a left lower lobectomy for left lower lobe bronchiectasis after splenectomy. The mean age was 34.6 years (range 18 to 63 years); there were 19 men and 5 women. The available data included history, radiological investigations (ultrasonography and computed tomography of the chest and abdomen), operative data, postoperative complications, and follow-up data.

RESULTS

All patients had a history of splenectomy and 10 had undergone subphrenic collection drainage either percutaneously or through open drainage a few years prior to the left lower lobectomy. Fourteen patients were lost to follow-up. The mean follow-up in 10 patients was 5.8 years (range 2 to 13 years).

CONCLUSIONS

Postsplenectomy left lower lobe bronchiectasis is an underestimated clinicopathological entity of bronchiectasis. It can be managed by a left lower lobectomy, with acceptable results.

Role of macrophage sialoadhesin in host defense against the sialylated pathogen group B Streptococcus

Abstract

Several bacterial pathogens decorate their surfaces with sialic acid (Sia) residues within cell wall components or capsular exopolysaccharides. Sialic acid expression can promote bacterial virulence by blocking complement activation or by engagement of inhibitory sialic acid-binding immunoglobulin-like lectins (Siglecs) on host leukocytes. Expressed at high levels on splenic and lymph node macrophages, sialoadhesin (Sn) is a unique Siglec with an elongated structure that lacks intracellular signaling motifs. Sialoadhesin allows macrophage to engage certain sialylated pathogens and stimulate inflammatory responses, but the in vivo significance of sialoadhesin in infection has not been shown. We demonstrate that macrophages phagocytose the sialylated pathogen group B Streptococcus (GBS) and increase bactericidal activity via sialoadhesin-sialic-acid-mediated recognition. Sialoadhesin expression on marginal zone metallophillic macrophages in the spleen trapped circulating GBS and restricted the spread of the GBS to distant organs, reducing mortality. Specific IgM antibody responses to GBS challenge were also impaired in sialoadhesin-deficient mice. Thus, sialoadhesin represents a key bridge to orchestrate innate and adaptive immune defenses against invasive sialylated bacterial pathogens.

Key message

Sialoadhesin is critical for macrophages to phagocytose and clear GBS.

Increased GBS organ dissemination in the sialoadhesin-deficient mice.

Reduced anti-GBS IgM production in the sialoadhesin-deficient mice.

Electronic supplementary material

The online version of this article (doi:10.1007/s00109-014-1157-y) contains supplementary material, which is available to authorized users.

Vaccination considerations in the asplenic patient

Overwhelming postsplenectomy sepsis is a rare but devastating and often lethal disease. Although vaccines are available, their proper use may be questioned. Standardization of protocols for the immunization of asplenic patients should be universal, thus, likely improving on their use. This article reviews the vaccines to be administered to the asplenic patient.

Effects of racing on reticulocyte concentrations in Greyhounds

BACKGROUND

Greyhounds have several hematologic variables that are outside of the respective reference intervals of other dog breeds. In addition, increases in HCT, total protein and HGB concentration, and RBC and WBC counts occur immediately after exercise; these values return to resting values within a few hour after racing.

OBJECTIVE

This study evaluated the effects of exercise on the concentration of reticulocytes in circulating blood in racing Greyhounds. We hypothesized that reticulocyte numbers are significantly increased immediately after a race, and return to baseline within one to 2 h postrace.

METHODS

Fifty actively racing Greyhounds at the Wheeling Island Racetrack and Casino were included in the study. Samples were collected by jugular venipuncture one day prior to racing at the kennel (resting), immediately after racing, and one to 2 h after the race (recovery). Reticulocyte counts were determined with an IDEXX ProCyte Dx Hematology Analyzer (IDEXX Laboratories, Inc., Westbrook, ME, USA). Due to a nonparametric distribution, the results were statistically compared using the Friedman test.

RESULTS

Reticulocyte concentrations were significantly different among the 3 sample collection times (P < .0001). There was a significant increase in reticulocyte concentration immediately after racing (P < .001); one to 2 h after racing, the reticulocyte numbers decreased significantly (P < .001) to counts comparable to resting samples.

CONCLUSION

The increase in reticulocyte concentration is probably related to splenic contraction secondary to the release of catecholamines, although premature bone marrow release could also account for these changes. Thus, it is important to consider a Greyhound's activity and degree of excitement when interpreting selected hematologic data in a clinical setting.

Hyposplenism: A comprehensive review. Part II: Clinical manifestations, diagnosis, and management

In the first part of this review, we described the physiological basis of splenic function and hypofunction. We also described the wide spectrum of diseases that can result in functional hyposplenism. In the second part of this review, we will be discussing the clinical picture, including complications, diagnostic methods, and management of hyposplenism.

Hyposplenism: A comprehensive review. Part I: Basic concepts and causes

Hyposplenism is not a rare condition and can complicate a remarkable number of illnesses. The two most time-honored diseases associated with the development of hyposplenism are sickle cell anemia and celiac disease. Hyposplenism is relatively easy to recognize by typical changes observed on the peripheral blood smear; including Howell-Jolly bodies, monocytosis, lymphocytosis, and increased platelet counts. Diagnosis can be confirmed by pitted RBC counts or 99Tc-labelled radiocolloid scan of the spleen; wherever available. Diagnosis needs to be made promptly to institute pneumococcal vaccination in a timely fashion and to recognize and treat bacterial infections promptly and aggressively because of the tendency of hyposplenic subject to develop fatal invasive disease. Overwhelming pneumococcal sepsis accounts for the major mortality cases in hyposplenic subjects; however severe infections with other encapsulated bacteria and protozoa have been reported. Hyposplenic individuals may also be at a higher risk for vascular, autoimmune and thrombotic diseases and they may have a higher risk of developing solid tumors. The commonly used pneumococcal polysaccharide vaccine is ineffective in asplenic subjects, because it requires the presence of IgM memory B cells, and should be given before splenectomy. In splenectomized, and functionally hyposplenic subjects, the pneumococcal conjugate vaccine is more effective, because it utilizes a T cell dependent mechanism, and should be the preferred vaccine in these circumstances.

Hematological manifestations of celiac disease

Celiac disease, an autoimmune disease once thought to be uncommon, is now being increasingly identified. Our improved diagnostic modalities have allowed us to diagnose more and more patients with atypical symptoms who improve on gluten-free diet (GFD). We discuss here the latest findings regarding the various hematological manifestations of celiac disease and their management. Anemia remains the most common hematological manifestation of celiac disease due to many mechanisms, and can be the sole presenting symptom. Other manifestations include thrombocytosis and thrombocythemia, leukopenia, thromboembolism, increased bleeding tendency, IgA deficiency, splenic dysfunction, and lymphoma. The diagnosis of celiac disease should always be kept in mind when a patient presents with unexplained and isolated hematological finding. Once diagnosed, patients should adhere to GFD and be educated about the potential complications of this disease. We herein present an algorithm for adequate management and follow-up.

Prospective randomized comparison of open versus laparoscopic management of splenic artery aneurysms: a 10-year study

BACKGROUND: The literature does not support the choice between open and laparoscopic management of splenic artery aneurysms (SAA). METHODS: We designed a prospective, randomized comparison between open and laparoscopic surgery for SAA. Primary end points were types of surgical procedures performed and clinical outcomes. Analysis was developed on an intention-to-treat basis. RESULTS: Fourteen patients were allocated to laparotomy (group A) and 15 to laparoscopy (group B). Groups displayed similar patient- and aneurysm-related characteristics. The conversion rate to open surgery was 13.3 %. The type of surgical procedure performed on the splenic artery was similar in the two groups: aneurysmectomy with splenic artery ligature or direct anastomosis was performed in 51 % and 21 % of patients in group A and in 60 % and 20 % in group B, respectively. The splenectomy rate was similar (14 % vs. 20 %). Postoperative splenic infarction was observed in one case in each group. Laparoscopy was associated with shorter procedures (p = 0.0003) and lower morbidity (25 % vs. 64 %, p = 0.045). Major morbidity requiring interventional procedures and blood transfusion was observed only in group A. Laparoscopy was associated with quicker resumption of oral diet (p < 0.001), earlier drain removal (p = 0.046), and shorter hospital stay (p < 0.01). During a mean follow-up of 50 months, two patients in group A required hospital readmission. In group B, two patients developed a late thrombosis of arterial anastomoses. CONCLUSIONS: Our study demonstrates that laparoscopy permits multiple technical options, does not increase the splenectomy rate, and reduces postoperative complications. It confirms the supposed clinical benefits of laparoscopy when ablative procedures are required but laparoscopic anastomoses show poor long-term results.

Splenic infarction in a patient with autoimmune hemolytic anemia and protein C deficiency

Splenic infarction is most commonly caused by cardiovascular thromboembolism; however, splenic infarction can also occur in hematologic diseases, including sickle cell disease, hereditary spherocytosis, chronic myeloproliferative disease, leukemia, and lymphoma. Although 10% of splenic infarction is caused by hematologic diseases, it seldom accompanies autoimmune hemolytic anemia (AIHA). We report a case of a 47-year-old woman with iron deficiency anemia who presented with pain in the left upper abdominal quadrant, and was diagnosed with AIHA and splenic infarction. Protein C activity and antigen decreased to 44.0% (60-140%) and 42.0% (65-140%), respectively. Laboratory testing confirmed no clinical cause for protein C deficiency, such as disseminated intravascular coagulation, sepsis, hepatic dysfunction, or acute respiratory distress syndrome. Protein C deficiency with splenic infarction has been reported in patients with viral infection, hereditary spherocytosis, and leukemia. This is a rare case of splenic infarction and transient protein C deficiency in a patient with AIHA.

Immunization in special populations

In summary, immunizations in special populations require understanding the underlying disease and how it might affect the immune system's ability to mount an antibody response to vaccines or predispose certain patient populations to developing certain serious infections. There is still a great need for research on the optimal timing of vaccines after transplants, how to assess protection and development of a protective antibody response after immunization, and whether certain groups (eg, HIV) need to be revaccinated after a certain amount of time if their antibody levels decline. In addition, there are limited data on efficacy of the newer vaccines in these special patient populations, which also requires further investigation.

A high fructose diet does not affect amphetamine self-administration or spatial water maze learning and memory in female rats

High energy diets can have a detrimental effect on brain plasticity. For example, a high fructose diet impairs spatial memory in male rats. The aim of the present study was to determine whether a high fructose diet impairs another form of learning and memory: drug reinforcement learning. Female Sprague-Dawley rats were fed a high fructose diet (60%) from weaning at postnatal day (PND) 21, then allowed to acquire lever-pressing maintained by intravenous (i.v.) amphetamine at PND 68, 109, or 165. Acquisition was tested on a fixed ratio one (FR1) schedule of reinforcement (0.025 mg/kg/infusion, 1h daily sessions, 10 sessions over 14 days), followed by testing for reinforcing efficacy on a progressive ratio (PR) schedule (0.025, 0.01, and 0.1mg/kg/infusion), 14 days of abstinence, and within-session extinction and reinstatement tests. Subsequently, water maze acquisition and retention were tested in these subjects as well as a separate cohort tested in the water maze only. The diet had no effect on acquisition, reinforcing efficacy, extinction, or reinstatement of amphetamine seeking. Nor did the diet alter any measures of spatial memory. The high fructose diet did decrease body mass and increase relative liver and spleen mass, but did not affect plasma triglyceride concentrations consistently. Together with prior research on males, these results suggest that the metabolism of fructose and the effects of a high fructose diet on learning and memory may be sex-dependent.

Isolated splenic metastasis from colorectal cancer

Splenic metastases are unusual, arising in less than 1% of all metastases. Isolated solitary splenic metastasis from colorectal carcinoma is considered exceptional. This rarity has been explained by several hypotheses relating to the anatomical, histological, and immunological features of the spleen. We review the reported cases of isolated solitary splenic metastasis from colorectal carcinoma and discuss the diagnostic and therapeutic options for this entity. We searched the English-language medical literature, using the Medline and Pubmed databases from January 1966 through July 2010, for articles reporting isolated splenic metastasis from colorectal carcinoma. Only 26 cases have been reported; four cases had synchronous splenic metastasis. Fifteen patients had regional lymph node involvement on diagnosis of primary carcinoma. The primary tumor was located in the left colon or in the rectum in 18 cases. Carcinoembryonic antigen (CEA) level was elevated in 73% of cases. All patients underwent curative splenectomy; only one patient had laparoscopic resection of the spleen. Mean reported survival interval was 19.5 months; only three patients were deceased at last follow-up. Solitary splenic metastasis from colorectal carcinoma is very rare; clinicians are advised to pay close attention when routinely evaluating patients with serial CEA levels and abdominal scans. Splenectomy seems to be the preferred treatment modality with improvement of long-term survival. However, definitive conclusions cannot be drawn from the small number of case reports available.

Preservation of splenic immunocompetence after splenic artery angioembolization for blunt splenic injury

BACKGROUND

Splenic artery angioembolization (SAE) is increasingly being used as an adjunct to nonoperative management for stable patients with blunt splenic injury (BSI). However, little is known about splenic immunocompetence after SAE. This study aims at assessing splenic immunocompetence after SAE for BSI.

METHODS

Peripheral blood was obtained from BSI patients (n = 8) who had SAE >6 months prior. Splenic immunocompetence was assessed by isolating mononuclear cells and incubating with CD4 and CD45RA and CD45RO antibody to analyze the proportion of T-cells expressing CD4 receptor, or coexpressing CD4 and either CD45RA or CD45RO receptors. Cells were counted by fluorescence-activated cell sorting and compared with trauma patients that had splenectomy for BSI also >6 months prior (n = 4, negative controls) and normal healthy volunteers with intact spleens (n = 4, positive controls).

RESULTS

The test was discriminatory for the asplenic state. %CD4 cells were significantly lower in splenectomized patients (16 ± 1) versus normal (40 ± 2), p < 0.05. This was due to significant decrease (8 ± 2 vs. 26 ± 4, p < 0.05) in %CD4CD45RA cells whereas the proportion of CD4CD45RO cells were maintained similar to normal. SAE patients had values (CD4, 36 ± 2, and CD4CD45RA, 24 ± 2) comparable to normal (p > 0.05) and significantly higher than splenectomized patients (p < 0.05). When the SAE group was subdivided into main (total, n = 4) and branch vessel (partial, n = 4) SAE, results were the same for both types of SAE.

CONCLUSION

Splenic immune function, measured by T-cell subset, generated only in the presence of an immunocompetent spleen, is preserved after SAE for BSI, main or partial.

Does splenectomy protect against immune-mediated complications in blunt trauma patients?

Activation of the innate immune system results from severe trauma and the resultant systemic inflammatory response is thought to mediate remote organ injury. In animal models, vagal-mediated innate immune responses have been shown to modulate proinflammatory cytokine release in response to trauma or sepsis. In those models, vagal nerve transaction and splenectomy decreased cytokine release and protected against lung injury and mortality. We hypothesized that, if similar mechanisms are active in humans, patients who require splenectomy for trauma would have better outcomes than injured patients without splenectomy. We performed a retrospective cohort study on 46,858 patients who sustained blunt liver or spleen injury utilizing the 2002 National Trauma Data Bank (NTDB). Blunt trauma patients who underwent splenectomy were compared with all patients with splenic injuries. Demographic parameters and the following outcome variables were compared: mortality, hospital length of stay (LOS), ICU length of stay (ILOS), mean ventilator days (VENT), and incidence of acute respiratory distress syndrome (ARDS). Groups were compared controlling for age, gender, injury severity score (ISS), emergency department (ED) blood pressure, and ED base deficit (BD) using multiple regression analyses. Patients that underwent splenectomy had significantly shorter LOS than patients who were managed nonoperatively or with splenorrhaphy: LOS,15.1 versus 19.3 d, P = 0.002; ILOS, 7.8 versus 10.6 d, P < 0.001; and VENT, 7.1 versus 11.4 d, P < 0.001. Adjusted mortality rates (OR 1.02; 95% CI 0.98-1.05; P = 0.29) and the reported incidence of ARDS were not significantly different between the two groups (2.4% versus 3.6%; P = 0.213). Patients who underwent splenectomy demonstrated better secondary outcomes than patients who were managed nonoperatively or with splenorrhaphy, even when controlling for injury severity and physiologic derangements. It is possible that the improved outcomes seen in the group undergoing splenectomy were due to favorable modulation of the human innate immune inflammatory response after trauma.

Clinical case report and literature review: metachronous colorectal splenic metastases

A 52-year-old woman with a rising carcinoembryonic antigen CEA, no clinical or radiological findings, a negative colonoscopy, and a positron emission tomography (PET) scan that revealed an isolated hypermetabolic lesion in the spleen. The patient underwent splenectomy by laparoscopic surgery. The pathological study confirmed the presence of an isolated metastasis to the spleen. This case reveals the rare occurrence of isolated splenic metastases in the context of colorectal cancer and illustrates the role of PET when a patient shows a rising CEA with negative clinicoradiological studies.

Complications of splenectomy

Surgical removal of the spleen, splenectomy, is a procedure that has significantly decreased in frequency as our understanding of the infectious complications of the asplenic state increased. The full spectrum and details of splenic function, however, have yet to be fully outlined. As a result, our comprehension of the long-term consequences of splenectomy remains incomplete. We review the evidence relating to the effects of splenectomy on infection, malignancy, thrombosis, and transplantation. Perhaps the best-defined and most widely understood complication of splenectomy is the asplenic patient's susceptibility to infection. In response to this concern, novel techniques have emerged to attempt to preserve splenic function in those patients for whom surgical therapy of the spleen is necessary. The efficacy of these techniques in preserving splenic function and staving off the complications associated with splenectomy is also reviewed in this article.

Hemolytic anemia due to warm autoantibodies

The diagnosis of autoimmune hemolytic anemia (AHA) requires evidence of shortened red blood cell (RBC) survival mediated by autoantibodies directed against autologous RBCs. About 80 percent of patients with AHA have warm-reactive antibodies of the IgG isotype; the remainder exhibit cold-reactive autoantibodies. Typical patients exhibit anemia, reticulocytosis, spherocytes and polychromasia on the blood film and a positive direct antiglobulin test (DAT). Increased indirect serum bilirubin, urinary urobilinogen and serum lactate dehydrogenase (LDH), and decreased serum haptoglobin are not required for the diagnosis, but are frequently present. Patients with AHA and no underlying associated disease are said to have primary or idiopathic AHA. AHA in patients with associated autoimmune disease and certain malignant or infectious diseases is classified as secondary. The etiology of AHA is unknown. Patients with symptomatic anemia require transfusion of RBCs. Prednisone and splenectomy may provide long term remission. Rituximab, intravenous immunoglobulin, immunosuppressive drugs and danazol have been effective in refractory cases and for patients who are poor candidates for surgery.

The Prevention and Management of Infections in Children with Asplenia or Hyposplenia

Overwhelming sepsis remains a significant complication of asplenia and hyposplenia. The mainstays of prevention are education, immunization, and prophylactic antibiotics. Evidence to base recommendation and guidelines is lacking. Such decisions as the specific immunizations required, the timing of immunizations, the duration of antibiotic prophylaxis, and the prevention of overwhelming postsplenectomy sepsis in children undergoing splenectomy are often empiric. This article reviews the current literature on the prevention and management of severe infections in children with underlying asplenia or hyposplenia.

Isolated metachronous splenic metastasis from synchronous colon cancer

Background

Isolated splenic metastases from colorectal cancer are very rare and there are only 13 cases reported in the English literature so far. Most cases are asymptomatic and the diagnosis is usually made by imaging studies during the evaluation of rising CEA level postoperatively.

Case presentation

A 76-year-old man underwent an extended left hemicolectomy for synchronous colon cancers located at the left flexure and the sigmoid colon. The tumors were staged as IIIC (T3N2M0) clinically and the patient received adjuvant chemotherapy. During the first year follow-up period, the patient remained asymptomatic with normal levels of laboratory tests including CEA measurement. However, a gradually rising CEA level after the 14^th postoperative month necessitated further imaging studies including computed tomography of the abdomen which revealed a mass in the spleen that was subsequently confirmed by ¹⁸FDG- PET scanning to be an isolated metastasis. The patient underwent splenectomy 17 months after his previous cancer surgery. Histological diagnosis confirmed a metastatic adenocarcinoma with no capsule invasion. After an uneventful postoperative period, the patient has been symptom-free during the one-year of follow-up with normal blood CEA levels, although he did not accept to receive any further adjuvant therapy. To the best of our knowledge, this 14^th case of isolated splenic metastasis from colorectal carcinoma is also the first reported case of splenic metastasis demonstrated preoperatively by ¹⁸FDG PET-CT fusion scanning which revealed its solitary nature as well.

Conclusion

Isolated splenic metastasis is a rare finding in the follow-up of colorectal cancer patients and long-term survival can be achieved with splenectomy.

Surgical Infection Society Guidelines for Vaccination after Traumatic Injury

BACKGROUND

Recommendations for vaccination of injured patients against infection are evolving. Newly-recognized infections, safety considerations, changing epidemiology, and redefinition of patient groups at risk are factors that may influence vaccine development priorities and recommendations for immunization. However, recommendations must often be formulated based on incomplete data, forcing reliance on expert opinion to address some crucial questions. These guidelines provide evidence-based recommendations for the prevention or treatment of infectious morbidity and mortality after traumatic injury, such as soft tissue wounds, human or animal bites, or after splenectomy.

METHODS

A panel of experts conducted a thorough review of published literature, as well as information posted on the internet at the websites of the U.S. Centers for Disease Control and Prevention, among others. MEDLINE was searched for the period 1966-2004 using relevant terms including "anthrax," "rabies," "tetanus," "tetanus toxoid," and " splenectomy," in combination with "vaccine" and "immunization." The Cochrane database was searched also. Reference lists were cross-referenced for additional relevant citations. All published reports were analyzed for quality and graded, with the strength of the recommendation proportionate to the quality of the supporting evidence.

RESULTS

Recommendations are provided for pre- and post-exposure prophylaxis of rabies and anthrax. For tetanus prophylaxis, recommendations are provided for prophylaxis of acute wounds stratified y age and prior immunization status, and for immunization of persons at high risk. After splenectomy, it is recommended that all persons ages 2-64 years receive 23- valent pneumococcal vaccine and meningococcal vaccine, with Haemophilus influenzae type B vaccine administered to high-risk patients as well (all are Grade D recommendations). Vaccination should be given two weeks before elective splenectomy (Grade C), or two weeks after emergency splenectomy (Grade D). A booster dose of pneumococcal vaccine is recommended after five years (Grade D); no re- vaccination recommendation is made for meningococcal or Haemophilus influenzae type B vaccine. Recommendations for prophylaxis of splenectomized children under the age of five years are also provided.

CONCLUSION

There are limited data on the use of vaccines after injury. This document brings together a disparate literature of variable quality into a discussion of the infectious risks after injury relevant to vaccine administration, a summary of safety and adverse effects of vaccines, and evidence-based recommendations for vaccination.

The influence of splenic metastases on survival in FIGO stage IIIC epithelial ovarian cancer

The purposes of this study were to compare the survival of ovarian cancer patients with splenic metastasis to patients without it and to evaluate the complications of the procedure. A retrospective study was performed on 34 patients with ovarian cancer who underwent splenectomy for initial cytoreduction at gynecologic oncology unit of Hacettepe University Hospitals between 1989 and 2001. All patients had FIGO stage IIIC disease and were left with <1 cm residual tumor after surgery. Eighteen patients (52.9%) had splenic metastasis. Patients with splenic metastasis tended poorer survival. Median survivals were 28.9 and 41.3 months for patients with splenic disease and for patients without it, respectively (P > 0.05). Univariate analysis revealed that performance status and histologic type influenced survival. Histologic type and performance status were identified as independent risk factors by multivariate analysis. Postoperative complications were developed in ten (29.4%) patients and three of these (8.8%) died in 1 month after operation. None of the complications was attributed directly to the splenectomy procedure. Complete surgical cytoreduction confers a survival benefit whether the parenchyma was involved or not. The splenectomy should be considered with its acceptable morbidity in selected patients who have a chance to achieve optimal debulking.

Antibody responses in postsplenectomy trauma patients receiving the 23-valent pneumococcal polysaccharide vaccine at 14 versus 28 days postoperatively

BACKGROUND

We have previously demonstrated, using functional antibody assays, that patients undergoing splenectomy for trauma exhibit a better response to pneumococcal immunization when vaccinated at 14 days postoperatively versus 1 or 7 days. However, patients immunized at 14 days failed to reach the response of normal controls. This study was conducted to determine whether even later immunization would improve the antibody response.

METHODS

Forty surviving patients undergoing emergent splenectomy were randomized to receive Pneumovax at 14 or 28 days after splenectomy. Blood samples were drawn at the time of vaccination (prevaccination) and 4 weeks later (postvaccination). A control group of 24 healthy adults was used for comparison. Antibody titers to four of the most common serotypes were determined by enzyme-linked immunosorbent assay and opsonophagocytic assay (OPA).

RESULTS

Samples from 38 patient were analyzed. Each serotype and each group tested demonstrated a statistically significant increase in geometric mean enzyme-linked immunosorbent assay immunoglobulin G antibody concentration (microg/mL) and OPA titer (1/dilution) after vaccination. There were no statistically significant differences (p >or= 0.07) in the immunoglobulin G antibody concentrations and OPA titers between the 14-day or the 28-day study groups when compared with normal healthy adults regardless of the serotype tested. In addition, there were no differences in the antibody responses between the 14-day and the 28-day study groups.

CONCLUSION

Despite our previous study suggesting that delay in vaccination after emergent splenectomy resulted in improved antibody response, antibody response was not improved any further by delaying vaccination to 28 days.

Peso do baço como fator prognóstico do tratamento cirúrgico de pacientes portadores de esquistossomose mansônica

OBJETIVO: Analisar pré-operatoriamente o peso do baço como fator prognóstico do tratamento cirúrgico de pacientes portadores de esquistossomose mansônica. MÉTODOS: Foram analisados 114 pacientes, portadores de esquistossomose mansônica com antecedentes de hemorragia digestiva, submetidos a tratamento cirúrgico. Os pacientes foram divididos em três grupos: Grupo 1 - baço menor que 500 gramas (17); Grupo 2 - baço entre 500 e 1.000 gramas (58); Grupo 3 - baço acima de 1.000 gramas (39). RESULTADOS: No Grupo 1 a recidiva hemorrágica foi de 17,6%, trombose da veia porta de 5,9% e não houve mortalidade. A incidência de hiperesplenismo pré-operatório foi de 29,4% e o calibre da veia porta foi de 1,1cm. No Grupo 2 a recidiva hemorrágica foi de 15,5%, trombose da veia porta de 10,3% e a mortalidade de quatro pacientes (6,9%) (dois pacientes no período pós-operatório e dois no seguimento tardio, hepatocarcinoma e hemorragia digestiva). A incidência de hiperesplenismo foi de 53,4% e o calibre médio da veia porta foi de 1,4cm. No Grupo 3 a recidiva hemorrágica foi de 12,8%, trombose da veia porta de 5,1% e uma mortalidade tardia de dois pacientes (linfoma e infarto agudo do miocárdio). A incidência de hiperesplenismo foi de 76,9% e o calibre da veia porta foi de 1,5cm. CONCLUSÕES: O peso do baço apresenta relação com o hiperesplenismo pré-operatório, calibre da veia porta e permanência hospitalar pós-operatória. Não encontramos relação com a incidência de varizes de fundo gástrico, recidiva de sangramento digestivo, trombose da veia porta, grau de fibrose periportal e dados bioquímicos.