Splenectomy and serious infections

Poor antibody response to pneumococcal polysaccharide vaccination suggests increased susceptibility to pneumococcal infection in splenectomized patients with hematological diseases

Patients with hematological diseases undergoing diagnostic or therapeutic splenectomy are at increased risk of pneumococcal infections. Vaccination is a straightforward option in preventing these infections. A well-defined cohort of splenectomized patients with hematological disorders was followed according to response to 23-valent pneumococcal capsular polysaccharide (Pneumovax N) vaccination. A total of 76 splenectomized patients (Hodgkin lymphoma, HL 26, non-Hodgkin lymphoma, NHL 19, immune-mediated cytopenias 28, and others 3) with a median age of 52 years (range 18-82 years) were included. Pneumococcal polysaccharide (PS) antibodies were determined using an enzyme-linked immunosorbent assay before vaccination, at peak, and follow-up. A poor response to vaccination was observed in 21 (28%) patients and a good response in 55 (72%), respectively. During the follow-up period of 7.5 years (range 3.5-10.5 years) after vaccination, and despite repeated revaccination in many cases, a total of five episodes (in three patients) of pneumococcal infections were reported, all confined to the poor responder group. Revaccination did not improve antibody levels in this group. The median age at vaccination was significantly higher in the group of poor responders (p=0.0006). None of the following factors could predict a poor antibody response: gender, disease activity or aggressiveness in hematological malignancies, previous radiotherapy and/or chemotherapy, time between splenectomy and pneumococcal vaccination, time between chemotherapy/radiotherapy and study pneumococcal vaccination (1 year), or the presence of hypogammaglobulinemia. In conclusion, a substantial proportion of splenectomized patients with hematological diseases mounted a poor PS antibody response and remained at risk for pneumococcal infections despite vaccination. In the absence of apt indirect clinical predictors of antibody response, with the exception of age, measurement of antibody levels seems to be a feasible method for early identification of this patient subgroup. Poor responders do not benefit from revaccination, and should be offered other prophylactic measures.

A prospective study on antibody response to repeated vaccinations with pneumococcal capsular polysaccharide in splenectomized individuals with special reference to Hodgkin's lymphoma

BACKGROUND

Splenectomy is accompanied by a life-long risk of overwhelming postsplenectomy infection (OPSI), mainly caused by polysaccharide (PS) encapsulated bacteria such as Streptococcus pneumoniae. Despite extensive prophylactic efforts the mortality and morbidity rates remain high. The present study was based on a strategy with a predefined vaccination algorithm including repeated 23-valent pneumococcal vaccinations and monitoring of pneumococcal antibody levels. The antibody levels of splenectomized Hodgkin's lymphoma (HL) patients were compared with those patients splenectomized due to immune-mediated cytopenias [autoimmune haemolytic anaemia (AIHA) and immune thrombocytopenic purpura (ITP)] and also individuals who were splenectomized because of trauma (TRAUMA).

METHODS

A total of 311 splenectomized individuals were included in this prospective study (208 HL; 15 AIHA; 60 ITP; 28 TRAUMA). Depending on their individual anti-PS antibody levels measured by enzyme-linked immunosorbent assay technique the patients were revaccinated with 23-valent pneumococcal PS vaccine up to four times in accordance with the predefined algorithm. For each vaccination occasion, serum was collected at vaccination, after 1 month +/- 2 weeks (peak), and after 1 year +/- 6 months (follow-up). Patient files, a national population-based database, and microbiological databases were checked for 124 HL patients to identify OPSI.

RESULTS

A significant response was recorded on primary vaccination as well as on two revaccination occasions for HL, AIHA/ITP, as well as TRAUMA patients. None of the variables age, gender, or time elapsed between splenectomy and first pneumococcal vaccination was found to be associated with mean PS antibody levels at prevaccination, peak or follow-up. No severe adverse events were reported. Amongst 124 clinically monitored HL patients, 10 OPSI were recorded in seven patients during the study period. One of these patients, a middle-aged female, died as a result of fulminant pneumococcal bacteraemia, which was her third OPSI during a 7-year period.

CONCLUSIONS

A significant response to pneumococcal PS vaccination was found in all three groups (HL, AIHA/ITP and TRAUMA) of splenectomized patients. Importantly, both primary and repeated vaccinations were safe. Until further knowledge is gained regarding the protective concentration of serotype-specific antibody concentrations we believe that the value of vaccination and frequent revaccination (every 1-5 years) in combination with education of patients and health care professionals and clinical monitoring is beneficial for these patients at risk for OPSI.

Risk factors for the development of invasive fungal infections in allogeneic blood and marrow transplant recipients

Blood and marrow transplantation (BMT) is increasingly used to treat malignant and nonmalignant diseases. Despite significant advances in the management of transplant recipients, however, fungal infections remain important life-threatening complications of BMT. Over the past two decades, the incidence of fungal infections in this population has continued to rise. Several factors predispose BMT recipients to invasive fungal infections. These include but are not limited to use of intensive myeloablative chemotherapy and radiation therapy combined with prolonged granulocytopenia; development of acute and chronic graft-versus-host disease; administration of immunosuppressive therapy, particularly using corticosteroids; use of central venous catheters; and prolonged impairment of cell-mediated immunity secondary to the underlying disease and post-transplant immunodeficiency. Environmental factors also play a key part in the pathogenesis of fungal infections. Therefore, infection-control measures are critical to the prevention of such infections. In addition, although Candida and Aspergillus species are still the major culprits, other opportunistic fungi have emerged in recent years.

Partial splenectomy in children under 4 years of age with hemoglobinopathy

BACKGROUND/PURPOSE

The risk of septicemia in postsplenectomy pediatric patients is approximately 2%. This risk is twice as great for children less than 4 years of age. In the first year of life this risk can be 30% or higher. Partial splenectomy is an alternative in patients with hemoglobinopathies. The authors attempt to assess the outcome of pediatric patients less than 4 years of age undergoing partial splenectomy using the Argon beam.

METHODS

In a tertiary care, university affiliated, dedicated children's hospital seven patients underwent partial splenectomy (PS) by the same surgeon from May 1993 to September 1995. The PS performed for trauma was excluded. Included were patients with hemoglobinopathies. Therefore, six patients were evaluated. Follow-up was from 6 months to 2 years. Pre- and postoperative blood transfusions, length of operation, estimated blood loss, length of hospital stay, postoperative complications, perfusion, and function of remnant spleen were evaluated.

RESULTS

Indications for splenectomy included sequestration crisis and hypersplenism. Percent splenectomy ranged from 65% to 75%. Average hospital stay was 6.3 days. Postoperative splenic function, measured by Pitt count and radionuclide spleen scan, was normal. Postoperatively there were no systemic infections, overwhelming postsplenectomy sepsis (OPSS), torsion of the splenic remnant, left upper quadrant fluid collections, or subphrenic abscesses. There were no deaths.

CONCLUSIONS

Partial splenectomy is a safe and effective procedure in children less than 4 years of age with hemoglobinopathies. The procedure as described yields minimal blood loss and retains immune competence. Partial splenectomy greatly reduces, and in some cases eliminates, the need for blood transfusions. PS should be considered the procedure of choice in children less than 4 years of age with sickle cell anemia or beta-thalassemia who require splenectomy.

An investigation of the filtration capacity and the fate of large filtered sterically-stabilized microspheres in rat spleen

Earlier we demonstrated that coating the surface of large model polystyrene microspheres (220-300 nm in diameter) with the block co-polymer polyoxyethylene/polyoxypropylene poloxamine-908 triggered their accumulation in the rat spleen by a filtration mechanism following intravenous administration [Moghimi, S.M., Porter, C.J.H., Muir, I.S., Illum, L. and Davis, S.S. (1991) Biochem. Biophys. Res. Commun. 177, 861-866]. We have now demonstrated that the macrophages of the red-pulp can effectively phagocytose the filtered poloxamine-coated microspheres 24 h post-administration. This could be the result of either the loss of the surface absorbed poloxamine, and hence the steric barrier, or 'neutralization' of the effect of the anti-phagocytic material poloxamine-908 within the spleen. In order to assess the capacity of the splenic uptake mechanism(s), rats received daily intravenous administration of unlabelled large poloxamine-908 coated microspheres (220 nm in diameter) for 4 days (daily-dosed animals). Control rats received daily saline injection. On the fifth day all animals were injected with either radiolabelled large (220 nm) or small (60 nm in diameter) poloxamine-coated polystyrene microspheres. Predosing dramatically decreased the splenic uptake of the large test microspheres but had no effect on the uptake of small test-microspheres. The failure of the spleen to take up particles was not associated with an increased circulatory level of microspheres. Surprisingly, both small and large coated microspheres were sequestered by the liver and accumulated in Kupffer cells as demonstrated by electron microscopy in daily-dosed animals. In contrast, the liver of control animals did not effectively sequester poloxamine-coated microspheres. Here, microspheres predominantly remained in blood. Sequestration of poloxamine-908 coated microspheres by Kupffer cells of the liver of daily-dosed animals was the result of opsonization by an unknown serum component.

Capnocytophaga canimorsus bacteraemia demonstrated by a positive blood smear. A case report

The observation of bacteria in a peripheral blood smear was conducive to the diagnosis of Capnocytophaga canimorsus septicaemia in a patient with no definite record of animal bites. Multiple rods were seen extracellularly and within the cytoplasm of neutrophils. The blood culture became positive after 18 h of incubation. Disseminated intravascular coagulation (DIC) was manifest and infarction of the spleen was suspected. Direct examination of peripheral blood smears could be a valuable adjunct in the diagnosis of overwhelming bacteraemia.

Partial splenectomy in sickle cell syndromes

Partial splenectomy was carried out in four children with homozygous sickle cell disease and eight children with sickle cell beta thalassaemia. It was performed in order to preserve splenic contribution to the host defence against infections while suppressing hypersplenism or the risk of recurrence of acute splenic sequestration. Indications for this surgical operation were acute splenic sequestration (n = 1), hypersplenism (n = 5), and acute splenic sequestration and hypersplenism (n = 6). Surgery was uneventful in 11 patients. A significant reduction of blood requirements and a significant decrease of the number of hospitalisations/patient/year were observed after splenectomy. No recurrence of hypersplenism or acute splenic sequestration occurred and no severe infection was noticed during the follow up period after surgery (mean (SD) 4.2 (2.8) years; range 6 months-7 years). Mean haemoglobin concentration and leucocyte and platelet counts increased after surgery. The benefit of partial splenectomy compared with total splenectomy to treat acute splenic sequestration or hypersplenism in sickle cell disease is discussed.

Inherited complement deficiency states: implications for immunity and immunological disease

The study of complement deficiency states and their influence on immune function has generated new insights and still provides a challenge to continued investigation. The association of classical pathway deficiencies (C1, C4, C2 or C3) with immunological diseases such as SLE and glomerulonephritis has contributed to current knowledge concerning complement-dependent immune complex handling and elimination. Susceptibility to systemic infection with encapsulated bacteria is encountered in most forms of inherited complement deficiency. Recurrent neisserial infection is the only clinical manifestation clearly associated with defects of the membranolytic sequence C5-C9, while deficiency of properdin, a component of the alternative activation pathway, appears to predispose to nonrecurrent meningococcal disease. Inherited complement deficiency is rare, but the perspective is widened by the more common occurence of acquired defects in immunological diseases, and the apparent requirement for efficient complement recruitment in host defense. Another aspect is the possibility that complement deficiency might alleviate or prevent inflammatory symptoms. Notably, complement deficiency has not been reported in classical rheumatoid arthritis. Considerations of this kind would be refuted or modified by findings of complement deficiency in single patients.

IgG subclass antibody responses to pneumococcal polysaccharide vaccine in splenectomized, otherwise normal, individuals

Subclasses of IgG antibodies to pneumococcal polysaccharide serotype antigens 4, 6A, and 23F were measured before and 4 weeks after vaccination with pneumococcal vaccine in young individuals splenectomized because of trauma and in a control group. An ELISA technique was applied. IgG2 anti-pneumococcal antibodies predominated before vaccination, especially against serotypes 4 and 6A. The youngest individuals in the splenectomy group tended to have lower IgG2 anti-pneumococcal antibody levels than the older ones. Vaccination induced antibodies of the IgG1 and IgG2 subclasses, and in some individuals also of the IgG4 subclass. Splenectomy does not seem to influence the IgG subclass pattern of antipneumococcal antibodies.

Partial splenectomy in homozygous beta thalassaemia

Partial splenectomy was performed on 30 patients with homozygous beta thalassaemia to reduce blood requirements and to avoid the risk of overwhelming postsplenectomy infections; 24 patients had thalassaemia major and six thalassaemia intermedia. Five patients received a high transfusion regimen before and after surgery and 25 a lower one. Follow up after surgery ranged from one to four years. Partial splenectomy improved the long term haematological state in the six patients with thalassaemia intermedia. Recurrence of hypersplenism occurred in nine of the 24 patients with thalassaemia major, however, and complete splenectomy was required. Serum IgM concentrations were not significantly modified by surgery. The mean (SD) residual spleen after surgery was 4.45 (2.36) cm measured by scintigraphy. No severe infections occurred after surgery; however, most patients were routinely treated with phenoxymethylpenicillin and the protective effect of the remaining spleen could not be exactly determined. Because of the possibility of recurrence of hypersplenism, routine partial splenectomy when splenectomy is needed in thalassaemia major is not advised, except in children under 5 years whose risk of overwhelming postsplenectomy infection is greatest.

Infection after splenectomy for Hodgkin's disease

The incidence of non-fatal infections after staging laparotomy in 95 adult patients with Hodgkin's disease was compared with that of 94 non-splenectomized patients. In addition, mortality of infections in 248 splenectomized patients was compared with mortality in 275 non-splenectomized patients. The observation time was 10 years from start of therapy. No difference was found between splenectomized and non-splenectomized adult Hodgkin's patients as to frequency and death from infection. However, the incidence of more serious infections was significantly higher in advanced disease (stage III and IV) as compared with localized disease (stage I and II). Deaths from rapid fatal infection occurred only in patients with advanced disease, unrespective of splenectomy.

Endotoxin release from neisseria meningitidis. Relationship between key bacterial characteristics and meningococcal disease

A method was established in order to measure total and filtrable (CF) endotoxin in cultures of Neisseria meningitidis strains. The Limulus lysate (LAL) test gave results which paralleled those of the standard rabbit pyrogen test and of gas chromatography (GLC), concerning detection of different CF endotoxin levels. Meningococci varied in their ability to produce CF endotoxin. Cultures of similar bacterial densities, whether with a high (E+) or a low (E-) release of endotoxin in CF, had both high yields of endotoxin in sonicated culture suspensions determined by the LAL test. GLC demonstrated only small differences in total LPS contents between E+ and E- strains. This suggests that strains with similar cell wall endotoxin contents may vary in CF endotoxin. Electron microscopy revealed that E+ strains presented a high number of free, outer cell wall fragments (blebs, tubuli, membranes and aggregates of such structures) in surroundings. Few such free, small structures were found around E- strains. The amount of CF endotoxin of E+ strains was in part a function of the number of colony forming units (CFU/ml), and generally followed the growth curve. Because of its moment of appearance, and also based on electron microscopy findings, CF endotoxin appeared mainly to be released from living bacteria. The CF level of endotoxin was low or not detected at all in cultures of E- strains although their cultures reached higher mean CFU-levels than the niveaus required for the detection of CF endotoxin in the E+ strains. The E+ property was strain dependent. Meningococci isolated from CSF or blood had a significantly higher proportion of E+ strains (88.2%) and a higher CF endotoxin titre (greater than or equal to 10(3); 34.5%), than isolates from carriers (32.3% and 10.8%, respectively) (p less than 0.001 and p less than 0.001, respectively). A high mean CFU/ml in cultures seemed to be more often associated with isolates from patients than from carriers, more often with the presence than abscence of capsular polysaccharide (p less than 0.05), and more often with the presence than absence of the E+ property (p = 0.002). E+ strains were mostly serogroupable (i.e. encapsulated), regardless of source of the isolate (99% case and 80% carrier isolates). In contrast, serogroupable bacteria were not necessarily E+ when isolated from carriers (54.8%). The serogroup most apt to cause disease tended to have the highest proportion of E+ strains and the highest level of CF endotoxin.(ABSTRACT TRUNCATED AT 400 WORDS)

Autoantibodies in individuals splenectomized because of trauma

Sera from 104 individuals splenectomized because of abdominal trauma were examined for the occurrence of 9 different autoantibodies. Our findings indicate that the occurrence of autoantibodies in splenectomized individuals without systemic disease is not increased and does not differ significantly from that found in an age- and sex-matched control population.

Polymorphonuclear neutrophil function and infections following splenectomy in childhood

22 subjects were controlled 3-23 yr after splenectomy due to childhood trauma (10), idiopathic thrombocytopenic purpura (9) or congenital spherocytosis (3). The control comprised a history of infections, physical examination, routine hematologic values, determinations of serum immunoglobulins, evaluation of complement activities, cultivations from throat and nasopharynx and polymorphonuclear neutrophil (PMN) function tests. 14 patients (63%) had increased susceptibility to recurrent bacterial infections (SBI), most often tonsillitis. All these patients also had abnormal PMN function. The other 8 patients with normal susceptibility to infections showed essentially normal PMN function. There were no differences between these groups with regard to indication for splenectomy, age at splenectomy or the time interval after splenectomy. This abnormal PMN function may explain the raised susceptibility to infections.

Comparison and definition of spleen and lymph node: a phylogenetic analysis

The hitherto largely unsolved problem with a biological definition of spleen versus lymph node seems possible to solve from a phylogenetic point of view. Thus, it is suggested that the spleen be defined as a hemopoietic organ which is able to filter blood with sinusoids. In contradistinction, a lymph node is defined as a hemopoietic organ which is able to filter lymph with sinusoids. Comparative anatomical studies show that the spleen appears as a condensation of the lymphomyeloid complex in the spiral fold of the gut in cyclostomes. The spiral fold spleen vanishes with the bony fishes, while in cartilaginous fishes a similar spleen appears in the dorsal mesentery. The dorsal spleen remains in a retroperitoneal position in higher vertebrates and is regarded as a specialized blood vessel compartment closely connected with the blood stream. In "higher" vertebrates the spleen is a stagnated organ because splenic functions are gradually transferred to other sites. The bone marrow takes over the erythro-, thrombo- and granulocytopoiesis while the lymph nodes take over the lymphocytopoiesis. This transfer of the splenic functions is first seen in anurans and seems to be a marvelous adaptation to life on land where the need for local defence against a large number of antigens is necessary before spread of the antigens to central parts of the body. In higher vertebrates, the great number of lymph nodes at peripheral positions, derived from the lymphatic vessels, are able to do so. It is demonstrated that the definitions of spleen and lymph nodes as hemopoietic organs which by their sinusoids are able to filter blood and lymph, respectively, are not only of semantic interest but also useful in regard the immunohematological system as an entity.

Abnormalities of B-cell activation and immunoregulation in splenectomized patients

Using a reverse hemolytic plaque assay as the effector system, we studied B-lymphocyte function in 12 patients after posttraumatic splenectomy, as well as in 25 normal individuals. The time interval between the splenectomy and the immunological studies varied between 2 days and 7 years. Compared to normal individuals, the splenectomized patients had markedly elevated numbers of spontaneous immunoglobulin-secreting cells (ISC) and severely decreased responses to the polyclonal activator pokeweed mitogen. A tendency towards normalization of these abnormalities, especially the high spontaneous ISC levels, could be observed during the time interval extending up to 7 years after splenectomy. In order to characterize the mechanism responsible for the altered immune response in splenectomized patients, co-culture experiments with unseparated and separated lymphocytes were performed. These revealed an impaired T-helper cell capacity as well as an intrinsic B-cell defect. Marker analyses with monoclonal antibodies revealed normal proportions with the exception of OKT 4 positive and B 1 positive cells that identify T-helper/inducer and peripheral B-cells respectively. We conclude that immune dysfunction in peripheral blood lymphocytes of splenectomized patients involves mainly the B-cell as well as the T-helper/inducer-cell population.

[Disorders of B cell activation in splenectomized patients]

Using a reverse hemolytic plaque assay as the effector system, we studied in vitro B-lymphocyte function in 12 patients after posttraumatic splenectomy as well as in 25 normal individuals. The time interval between the splenectomy and the immunological studies varied between 2 days and 7 years. Compared to normal individuals, the splenectomized patients had markedly elevated numbers of spontaneous immunoglobulin-secreting cells and severely decreased responses to the polyclonal activator pokeweed mitogen, indicating an in vivo polyclonal B-cell activation. A tendency towards normalization of these abnormalities, especially the high spontaneous ISC levels, could be observed during the time interval extending up to 7 years after splenectomy. In order to characterize the mechanism responsible for the altered immune response in splenectomized patients, in vitro experiments were performed with separated lymphocytes. These revealed an impaired T-helper cell capacity as well as an intrinsic B-cell defect. Marker analysis with monoclonal antibodies revealed normal proportions with the exception of OKT 4 positive and B 1 positive cells that identify T-helper/inducer and peripheral B-cells, respectively. We conclude that immune dysfunction in peripheral blood lymphocytes of splenectomized patients involves mainly the OKT 4 positive cell population.

IgM and IgG response to pneumococcal polysaccharide vaccine in normal individuals and individuals splenectomized due to trauma

Twenty-one young, splenectomized, healthy individuals (S group) and ten healthy individuals (K group) were vaccinated with a 14-valent pneumococcal polysaccharide vaccine. All individuals in the S group were splenectomized due to abdominal trauma. IgM and IgG antibodies against each of the 14 pneumococcal serotypes were determined by enzyme-linked immunosorbent assay. Serum concentrations of IgM and IgG were measured by radial immunodiffusion. The mean prevaccination IgM pneumococcal antibody level was lower in the S group than in the K group for most of the serotypes. The mean total serum IgM was considerably reduced in the S group. Vaccination induced a significant IgM pneumococcal antibody response in both groups, but the response tended to be smaller in the S than in the K group. These findings may appear compatible with suboptimal immune regulation in the splenectomized individuals. There were small variations between the total serum IgG and the prevaccination IgG pneumococcal antibody level in the two groups. Both groups obtained a significant IgG pneumococcal antibody response after vaccination to most of the serotypes.

The asplenic patient: a consideration for antimicrobial prophylaxis

Removal of the spleen predisposes the patient to the development of overwhelming sepsis without a primary site of infection. Transient, usually asymptomatic, bacteremias occur in a wide variety of dental manipulations, particularly those involving the mucous membranes. Occasionally these bacteremias can give rise to serious complications in susceptible patients. A prophylactic preoperative and postoperative antimicrobial regimen is presented for asplenic patients undergoing bacteremia-causing dental treatment.

Neutropenia due to beta lactamine antibodies

Neutropenia developed in 13 patients during treatment with beta lactamines. The time of onset ranged from eight to 27 days after beginning treatment and occurred with doses as low as 40 mg/24 hours. Concomitant symptoms were eosinophilia, rashes, and fever. Leucoagglutinins were detected in eight out of nine patients by the microleucoagglutination technique. Clinical and serological findings suggested that neutrophils become sensitised as a result of absorption on the cell membrane of drug-antibody immune complexes. An immune mediated pathogenesis for neutropenia induced by beta lactamine seems highly probable.

Role of spleen in immune response to polyvalent pneumococcal vaccine

The immune response of lymphocytes to subcutaneously administered pneumococcal vaccine was studied in five patients without spleens and in five healthy subjects. Seven days after immunisation circulating B cells synthesising IgG antipneumococcal capsular polysaccharides (anti-PCP) appeared in both groups. Twenty one days after vaccination this B cell population had disappeared and a B cell subset which secreted IgM and IgG anti-PCP in the presence of pokeweed mitogen was detected in the normal but not in the splenectomised subjects. In the splenectomised group polyclonal IgM synthesis induced by pokeweed mitogen was defective. It was concluded that the early events of the immune response to PCP may be mediated by lymph nodes but that, later, the spleen acquires a central role in producing lymphocyte subsets capable of synthesising specific antibodies and that this might explain the increased sensitivity of splenectomised subjects to pneumococcal infection.

Overwhelming infection after splenectomy in spite of some spleen remaining and splenosis. A case report

A fatal case of overwhelming postsplenectomy pneumococcal sepsis is presented occurring in a 37-year-old female 11 years after removal of the spleen because of traumatic rupture. The patient died 11 h after admission to hospital and about 32 h after sudden onset of illness. At necropsy splenic tissue, splenosis, disseminated intravascular coagulation, and thrombi within the arterioles consisting of gram-positive cocci and adrenal hemorrhage were found. The clinical, laboratory, and postmortem findings are described. Reports had been published of 41 other cases of overwhelming postsplenectomy infection (OPSI) in patients aged 20 years or more, but only three of these cases of OPSI syndrome occurred in spite of remaining splenic tissue. The longest interval between extirpation of spleen and subsequent sepsis was 42 years, indicating a small but lifelong risk of severe infection in asplenic patients. In view of the literature, the role of spleen in infection defence, the splenic function in blood clearance, and the prevention of postsplenectomy infections by antibiotic prophylaxis, pneumococcal vaccine, and reimplantation of autochthonous splenic tissue or infrared contact coagulation are discussed.

Postsplenectomy infections in Danish children splenectomized 1969-1978

During the 10-year period 1969-1978 456 splenectomies in children 0-15 years old were registered in Denmark. The underlying disease in 56% was traumatic splenic rupture, in 20% hereditary spherocytosis, in 13% idiopathic thrombocytopenic purpura and in 11% various other diseases. Three hundred and eighty-four (84%) could be followed retrospectively for a mean period of 6.2 years after splenectomy. Twenty-one (5.5%) contracted bacteraemia or meningitis, in 15 (71%) caused by Streptococcus pneumoniae, and 6 (1.6%) died from the infection. The frequency of postsplenectomy infection (PSI) was lower in children with splenic rupture (2.5%) than in those with hereditary spherocytosis (4.9%), idiopathic thrombocytopenic purpura (11.5%) and Hodgkin's disease (13.8%). Sixteen percent of children splenectomized before the age of 4 years versus 4% above that age developed PSI. Ninety-five percent of the PSI cases occurred less than 6 years after splenectomy. The incidence of severe pneumococcal bacteraemia and pneumococcal meningitis in the splenectomized was 284 times that of non-splenectomized children.

Chronic neutrophilic leukaemia with enlarged lymph nodes and lysozyme deficiency

A further case of chronic neutrophilic leukaemia is reported and compared to fourteen previously reported cases. The presence of enlarged lymph nodes as the first clinical sign and the existence of a relative lysozyme deficiency of the granulocytes were striking features.

Late infections following splenectomy in Hodgkin's disease

Here 145 reported post-splenectomy infections in 115 patients with Hodgkin's disease are reviewed. Such infections can occur at any age (median age 19.8 years) and the interval from splenectomy to the infection is quite variable (median 21.9 months). Most infections are present clinically as pneumonia, septicemia, meningitis, or a combination thereof, with the most common offending organism being pneumococcus. The infection can be fulminant and even fatal. It is recommended that the spleen should only be removed when essential. A staging laparotomy and splenectomy seem justifiable only in cases of Hodgkin's disease where a change of staging would lead to a change of planned therapy. Prophylactic penicillin should be administered at least for 3 years and possibly indefinitely since post-splenectomy infections can occur many years later. Pneumococcal vaccine should also be given before any chemotherapy or radiotherapy is initiated. Prompt and aggressive treatment should be given when post-splenectomy infection is diagnosed.

Antibody response and opsonization afer pneumococcal vaccination in splenectomized children and healthy persons

A significant rise in antibody against pneumococcal types 3, 6A and 25 after pneumococcal vaccination could be demonstrated in 26 of 30 individuals (87%) using an enzyme-linked immunosorbent assay. Similar geometric mean antibody fold increases were found in splenectomized children, non-splenectomized children and healthy adults for types 6A and 25. Splenectomized children exhibited a somewhat lower, but not statistically significant, geometric mean antibody fold increase against type 3 (p = 0.10), as compared to non-splenectomized children. For the whole group a negative correlation could be demonstrated between prevaccination antibody concentration and antibody fold increase after vaccination. After vaccination an enhanced serum opsonic activity against type 3 was found by granulocyte glucose-l-14C oxidation for the whole group of 30 patients (p less than 0.05) but nine individual patients (30%) failed to exhibit an increase. No differences between the three patient groups were demonstrable. Changes in serum opsonic activity could not be detected by a pneumococcal bactericidal assay.

Antibody response to pneumococcal vaccine in splenectomized adults and adolescents

The antibody response of 67 splenectomized adults and adolescents with benign underlying diseases to a 14-valent pneumococcal capsular polysaccharide vaccine was determined by an enzyme-linked immunosorbent assay. It was not significantly different from that of 12 healthy non-splenectomized adult volunteers for 13 of the 14 polysaccharide antigens studied. Residual splenic tissue as detected by Tc-scintigraphy was without any influence on the vaccination response. In comparison 5 untreated splenectomized adults with malignant diseases and 11 splenectomized adults receiving immunosuppressive therapy exhibited a significantly reduced combined geometric mean of their postvaccination antibody concentrations (all 14 antigens added) and of their combined geometric mean antibody fold increase as compared to the healthy non-splenectomized adults. The reduction in antibody response was most pronounced in the group of immunosuppressed patients. Immunogenicity of each of the 14 vaccine antigens varied considerably as judged by the geometric means of the postvaccination arbitrary antibody concentrations. Also individual variation in postvaccination antibody concentration against each antigen was large.

Chronic idiopathic thrombocytopenic purpura (ITP): site of platelet sequestration and results of splenectomy. A study of 197 patients

51Cr-platelet kinetics study was performed in 197 patients with chronic ITP after corticosteroid therapy had failed to induce a long lasting remission. The incidence of splenic, spleno-hepatic, hepatic and diffuse platelet sequestration site was 58%, 17%, 6% and 19%, respectively. Splenic and spleno-hepatic sequestration sites were more frequent in patients less than 30 years old and in patients with a platelet count lower than 50 x 10(9)/1. 111 patients were splenectomized shortly after the study. Normalization of the platelet count was obtained more frequently in patients with splenic and spleno-hepatic sequestration than in the others. Labelled platelet sequestration site was the best predictor of the outcome of splenectomy. Platelet kinetics is a non-invasive investigation that should be performed early after the diagnosis of chronic ITP in all patients eligible for splenectomy.