Postsplenectomy sepsis 10 years or more after operation

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Pneumococcal purpura fulminans in asplenic or hyposplenic patients: a French multicenter exposed-unexposed retrospective cohort study

Background

Pneumococcal infections remain the main cause of overwhelming post-splenectomy infections, and purpura fulminans may develop in almost 20% of patients with overwhelming post-splenectomy infection. We aimed at describing the impact of asplenia/hyposplenia on the clinical features and the outcomes of adult patients admitted to the intensive care unit (ICU) for pneumococcal purpura fulminans.

Methods

A 17-year national multicenter retrospective cohort study included adult patients admitted to 55 French ICUs for an infectious purpura fulminans from 2000 to 2016. Patients with pneumococcal purpura fulminans were analyzed according to the absence or presence of asplenia/hyposplenia.

Results

Among the 306 patients admitted to the ICU for purpura fulminans, 67 (22%) had a pneumococcal purpura fulminans, of whom 34 (51%) had asplenia (n = 29/34, 85%) or hyposplenia (n = 5/34, 15%) and 33 (49%) had eusplenia. The prevalence of pneumococcal purpura fulminans was seven times higher in asplenic/hyposplenic patients compared to eusplenic patients with purpura fulminans (n = 34/39, 87% vs. n = 33/267, 12%; p < 0.001). The median time interval between the occurrence of asplenia/hyposplenia and ICU admission was 20 [9–32] years. Pneumococcal vaccine coverage was 35% in asplenic/hyposplenic patients. Purpura was more frequently reported before ICU admission in asplenic/hyposplenic patients (n = 25/34, 73% vs. n = 13/33, 39%; p = 0.01). The rate of bacteremia did not differ between asplenic/hyposplenic and eusplenic patients (n = 31/34, 91% vs n = 27/33, 82%; p = 0.261). SAPS II (60 ± 14 vs. 60 ± 18; p = 0.244) and SOFA (13 [1–5] vs. 14 [1–4, 6]; p = 0.48) scores did not differ between asplenic/hyposplenic and eusplenic patients. There were no significant differences between asplenic/hyposplenic and eusplenic patients regarding the rate of limb amputation (n = 9/34, 26% vs. 15/33, 45%; p = 0.11) and hospital mortality (n = 20/34, 59% vs. n = 15/33, 45%; p = 0.27).

Conclusions

Half of pneumococcal purpura fulminans episodes occurred in asplenic or hyposplenic patients. Pneumococcal vaccine coverage was reported in one third of asplenic/hyposplenic patients. Half of pneumococcal purpura fulminans episodes occurred more than 20 years after splenectomy. Outcomes of pneumococcal purpura fulminans did not show significant differences between patients with or without asplenia or hyposplenia, although the small number of patients included limited our power to detect potential differences between groups.

Indian Antimicrobial Prescription Guidelines in Critically Ill Immunocompromised Patients

How to cite this article: Kulkarni AP, Sengar M, Chinnaswamy G, Hegde A, Rodrigues C, Soman R, Khilnani GC, Ramasubban S, Desai M, Pandit R, Khasne R, Shetty A, Gilada T, Bhosale S, Kothekar A, Dixit S, Zirpe K, Mehta Y, Pulinilkunnathil JG, Bhagat V, Khan MS, Narkhede AM, Baliga N, Ammapalli S, Bamne S, Turkar S, Bhat KV, Choudhary J, Kumar R, Divatia JV. Indian Journal of Critical Care Medicine 2019;23(Suppl 1): S64-S96.

Splenic abscess owing to cancer at the splenic flexure: A case report and comprehensive review

BACKGROUND

The cancer of the splenic flexure of the colon is a rare medical entity with severe morbidity because of its insidious onset.

METHODS

We present the case of a 59-year-old male patient with dull left upper quadrant pain, leukocytosis, and anemia. A splenic abscess described as an air-fluid level with splenocolic fistula was found on CT scan imaging. Surgery was done for splenic pus drainage. He was again admitted 2 months later for intestinal obstruction.

RESULTS

An exploratory laparotomy showed multiple hard, gray liver nodules as well as a hard mass in the small bowel. Owing to extensive adhesions and a late stage of cancer involvement, the splenic flexure tumor was not resected. A loop transverse colostomy was done and a Coloplast Colostomy bag placed. We also reviewed the literature-linking colon cancer and splenic abscess with specific attention to the carcinoma of the splenic flexure. As the latter invades through the spleen matter, there is the creation of a splenocolic fistula, which allows the migration of normal gut flora into the spleen. This leads to the formation of the splenic abscess.

CONCLUSION

This is the 13 case report pertaining to invading colonic cancer causing a splenic abscess. Although the treatment for splenic abscesses is shifting from splenectomy to image-guided percutaneous pus drainage, the few reported cases make the proper management of such complication still unclear.

Low immunoglobulin M memory B-cell percentage in patients with heterotaxy syndrome correlates with the risk of severe bacterial infection

BACKGROUND

Patients with heterotaxy syndrome, commonly associated with complex congenital heart disease (CHD), exhibit a higher risk of severe bacterial infection (SBI). We sought to define the change of a novel immunologic marker, the immunoglobulin M (IgM) memory B-cell percentage, and its association with SBI.

METHODS

We enrolled 46 (M/F 29/17) heterotaxy syndrome patients (42 right atrial isomerism (RAI) and 4 left atrial isomerism (LAI)) aged > 1 y during the period 2010-2012 in a tertiary care center. We analyzed IgM(+)CD27(+) memory B-cell percentages. Patients with simple and complex CHD served as controls.

RESULTS

The mean IgM memory B-cell percentages were the lowest in the heterotaxy syndrome group, compared with those in complex and simple CHD groups (1.8 ± 2.1 vs. 3.9 ± 3.2 vs. 5.1 ± 4.7, P < 0.001). In the heterotaxy syndrome group, 41.3% had low IgM memory B-cell percentages (<1% of B cells). Seven had a history of community-acquired SBI and 85.7% of these had low IgM memory B-cell percentages, which was the only significant factors related to community-acquired SBI (P = 0.028).

CONCLUSION

The memory B cell and IgM memory B-cell percentages are low in patients with heterotaxy syndrome, and the presence of IgM memory B-cell percentage < 1% correlates with community-acquired SBI.

Immune profile of asplenic patients following single or double vaccine administration: A longitudinal cross-sectional study

OBJECTIVE

Splenectomy poses a lifelong threat for the development of uncontrolled sepsis despite vaccination. As it is impractical to measure the levels of each antibody against 23 most frequent bacterial serotypes, different surrogate markers of immune response should be identified.

MATERIAL AND METHODS

Forty-eight patients with benign disorders were vaccinated with Pneumo-23 and Act-HIB before or at the day of surgery. The immunological response and opsonization capacity of the patients after splenectomy was analyzed through the quantitative measurement of IgG, IgM, C3, and C4 titers; flow-cytometric analysis of (CD3+) T-lymphocytes and (CD19+) B-lymphocytes; and isolation of CD27+ B cells by immunomagnetic positive selection. Blood samples were drawn at the sixth month and 5 and 7 years after surgery.

RESULTS

The mean follow-up period was 98.4 months. All the patients in this series had normal IgG, C3, C4 levels and a normal distribution of CD19+ B-cells and CD8+ T-cells in three follow-up periods. Moreover, C3 levels markedly improved to 133.5±37.3 mg/dL at 5 years and remained stable thereafter. CD19+ B-lymphocyte values have progressively improved to the normal range in 98% patients at 7 years. Further, low levels of CD27+ B-cell population (memory cells) was observed in only 12.5% patients at the last follow-up. Adequate seroconversion of IgG, IgM with normal C3, C4, and CD19+ B-cell levels were accomplished in almost all patients. Early postoperative death and late overwhelming infections did not occur.

CONCLUSION

Our results are indicative of the resumption of the immune function following Pneumo-23 and Act-HIB administrations, instigated by the probable activation of B cells and adequate production of C3, C4, IgG, and IgM antibodies in remote lymphoid tissues.

Benefits and risks of splenectomy

Splenectomy is a powerful therapeutic procedure in a wide variety of medical disorders provided that it is not undertaken lightly and the risks are weighed against the potential benefits in each individual case. Most of this risk seems to be due to the underlying splenectomy indication and not to splenectomy alone. There has been an increased tendency in recent years towards splenic preservation to prevent not only the risk of subsequent overwhelming post-splenectomy infection (OPSI) but the long term risk of cardiovascular complications. As there is no condition that can be cured by splenectomy, this paper reviewed the rationale behind the indications for, and the associated risks.

METHOD

Electronic searches of the medline (PubMed) database, Cochrane library, and science citation index were performed to identify original published studies on splenectomy. Relevant articles were searched from relevant chapters in specialized texts and all included.

Meningococcal disease and the complement system

Despite considerable advances in the understanding of the pathogenesis of meningococcal disease, this infection remains a major cause of morbidity and mortality globally. The role of the complement system in innate immune defenses against invasive meningococcal disease is well established. Individuals deficient in components of the alternative and terminal complement pathways are highly predisposed to invasive, often recurrent meningococcal infections. Genome-wide analysis studies also point to a central role for complement in disease pathogenesis. Here we review the pathophysiologic events pertinent to the complement system that accompany meningococcal sepsis in humans. Meningococci use several often redundant mechanisms to evade killing by human complement. Capsular polysaccharide and lipooligosaccharide glycan composition play critical roles in complement evasion. Some of the newly described protein vaccine antigens interact with complement components and have sparked considerable research interest.

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.

Pneumococcal infections and adult with risk factors

Streptococcus pneumoniae is an important bacterium in humans, and is a cause of upper and lower respiratory tract infections, meningitis, bacteremia, and/or invasive infections. An analysis of literature allows identifying the main risk factors; spleen dysfunctions, sickle cell anemia, alcohol abuse, chronic liver disease, cirrhosis, ischemic cardiac diseases, congestive cardiac failure, diabetes mellitus, obesity, chronic lung disease, immunodeficient patients including HIV infection, and old age. S. pneumoniae infections are more frequent and more severe in these patients. The pathophysiological mechanisms involved may be associated. These populations at risk should receive anti-pneumococcal vaccination. The availability of a 13 valent conjugate vaccine for adult opens new perspectives, but its clinical effectiveness needs to be proved for these patients at risk.

Clinical spectrum of serious bacterial infections among splenectomized patients with hemoglobinopathies in Israel: a 37-year follow-up study

PURPOSE

Patients with hemoglobinopathies who undergo splenectomy are at risk for invasive infections. The aim of this investigation was to present the clinical spectrum of infections in splenectomized patients.

METHODS

The study cohort comprised 54 splenectomized patients with beta-thalassemia (β-thalassemic) and sickle cell disease. The incidence of serious invasive bacterial infections was recorded. All patients received pneumococcal vaccine and all received oral prophylactic penicillin.

RESULTS

A total of 22 episodes of serious bacterial infections were identified in 19 patients among the study cohort of 54 splenectomized patients (35%). The clinical spectrum included sepsis (10 patients), bacteremia (8), liver abscess (1), forearm abscess (1), and urinary tract infection (2). The most frequent pathogens were Escherichia coli (8 cases), Steptococcus pneumoniae (5), and Campylobacter (2). 22 patients with β thalassemia died during the study period: 6 due to bacterial infection and 18 due to cardiomyopathy. The time elapsed between splenectomy and S. pneumoniae infection was significantly shorter than that between splenectomy and infections caused by other pathogens (18 ± 14 vs. 115 ± 93 months, respectively; p = 0.035).

CONCLUSIONS

Splenectomized patients with β thalassemia and sickle cell disease are predisposed to severe infections, with the majority of these infections being caused by Gram-negative microorganisms. The attending physician(s) should take these findings into consideration when deciding upon an empiric antibiotic treatment for splenectomized patients who present with fever or sepsis.

B-cells need a proper house, whereas T-cells are happy in a cave: the dependence of lymphocytes on secondary lymphoid tissues during evolution

A fundamental tenet of immunology is that adaptive immune responses are initiated in secondary lymphoid tissues. This dogma has been challenged by several recent reports. We discuss how successful T cell-mediated immunity can be initiated outside of such dedicated structures, whereas they are required for adaptive humoral immunity. This resembles an ancient immune pathway in the oldest cold-blooded vertebrates, which lack lymph nodes and sophisticated B-cell responses including optimal affinity maturation. The T-cell, however, has retained the capacity to recognize antigen in a lymph node-free environment. Besides bone marrow and lung, the liver is one organ that can potentially serve as a surrogate lymphoid organ and could represent a remnant from the time before lymph nodes developed.

Treatment modalities for hypersplenism in liver transplant recipients with recurrent hepatitis C

Hepatitis C is the most common indication for orthotopic liver transplantation in the United States. Unfortunately, hepatitis C recurs universally in the transplanted liver and is the major cause of decreased graft and patient survival. The combination therapy of interferon and ribavirin has been shown to be the most effective therapy for recurrent hepatitis C. However, pre- and post-transplant hypersplenism often precludes patients from receiving the antiviral therapy. Splenectomy and partial splenic embolization are the two invasive modalities that can correct the cytopenia associated with hypersplenism. In this report we review the two treatment options, their associated outcomes and complications.

Management of splenic abscess: report on 16 cases from a single center

OBJECTIVES

Splenic abscess is an uncommon disease, with a reported incidence of 0.14-0.7% in autoptic series. The best treatment option remains unclear. We report our experience of percutaneous drainage of splenic abscess under ultrasound (US) guidance.

METHODS

From 1979 to 2005, 16 consecutive patients (12 male and four female; mean age 39.9 years, range 16-72 years) were diagnosed with splenic abscess by means of US, and were treated with medical therapy alone or combined with US-guided percutaneous aspiration or catheter drainage.

RESULTS

Ten of 16 patients had bacterial abscesses (including one case of tubercular abscess), two had an amebic abscess, and four had fungal abscesses. Seven of ten patients with bacterial abscesses were successfully treated with fine needle aspiration alone, one patient was successfully treated with fine needle aspiration for one abscess and catheter drainage for another, and one patient, who subsequently required a splenectomy for an abdominal trauma, successfully underwent percutaneous catheter drainage alone. Four patients with fungal lesions were treated with medical therapy alone, and two patients later required a splenectomy. One patient with a bacterial abscess due to endocarditis was treated with medical therapy alone, and his recovery was uneventful.

CONCLUSIONS

US-guided percutaneous aspiration of splenic abscesses is a safe and effective procedure. It can be used as a bridge to surgery in patients who are critically ill or have several comorbidities. Percutaneous aspiration may allow complete non-operative healing of splenic abscesses or temporize patients at risk for surgery.

Guidelines for the diagnosis and management of hereditary spherocytosis

Hereditary spherocytosis (HS) is a heterogeneous group of disorders with regard to clinical severity, protein defects and mode of inheritance. It is relatively common in Caucasian populations; most affected individuals have mild or only moderate haemolysis. There is usually a family history, and a typical clinical and laboratory picture so that the diagnosis is often easily made without additional laboratory tests. Atypical cases may require measurement of erythrocyte membrane proteins to clarify the nature of the membrane disorder and in the absence of a family history, occasionally molecular genetic analysis will help to determine whether inheritance is recessive or non-dominant. It is particularly important to rule out stomatocytosis where splenectomy is contraindicated because of the thrombotic risk. Mild HS can be managed without folate supplements and does not require splenectomy. Moderately and severely affected individuals are likely to benefit from splenectomy, which should be performed after the age of 6 years and with appropriate counselling about the infection risk. In all cases careful dialogue between doctor, patient and the family is essential. Laparoscopic surgery, when performed by experienced surgeons, can result in a shorter hospital stay and less pain.

The C-type lectin SIGN-R1 mediates uptake of the capsular polysaccharide of Streptococcus pneumoniae in the marginal zone of mouse spleen

SIGN-R1, a recently discovered C-type lectin expressed at high levels on macrophages within the marginal zone of the spleen, mediates the uptake of dextran polysaccharides by these phagocytes. We now find that encapsulated Streptococcus pneumoniae are rapidly cleared by these macrophages from the bloodstream, and that capture also takes place when different cell lines express SIGN-R1 after transfection. To assess the role of the capsular polysaccharide of S. pneumoniae (CPS) in the interaction of SIGN-R1 with pneumococci, we first studied binding and uptake of serotype 14 CPS in transfected cells. Binding was observed and was of a much higher avidity (3000-fold) for CPS 14 than dextran. The CPSs from four different serotypes were also cleared by marginal zone macrophages in vivo. To establish a role for SIGN-R1 in this uptake, we selectively down-regulated expression of the lectin by pretreatment of the mice with SIGN-R1 antibodies, including a newly generated hamster monoclonal called 22D1. For several days after this transient knockout, the marginal zone macrophages were unable to take up either CPSs or dextrans. Therefore, marginal zone macrophages in mice have a receptor that interacts with capsular pneumococcal polysaccharides, setting the stage for further studies of the functional consequences of this interaction.

Pneumococcal conjugate vaccines overcome splenic dependency of antibody response to pneumococcal polysaccharides

Protection against infections with Streptococcus pneumoniae depends on the presence of antibodies against capsular polysaccharides that facilitate phagocytosis. Asplenic patients are at increased risk for pneumococcal infections, since both phagocytosis and the initiation of the antibody response to polysaccharides take place in the spleen. Therefore, vaccination with pneumococcal polysaccharide vaccines is recommended prior to splenectomy, which, as in the case of trauma, is not always feasible. We show that in rats, vaccination with a pneumococcal conjugate vaccine can induce good antibody responses even after splenectomy, particularly after a second dose. The spleen remains necessary for a fast, primary response to (blood-borne) polysaccharides, even when they are presented in a conjugated form. Coadministration of a conjugate vaccine with additional nonconjugated polysaccharides of other serotypes did not improve the response to the nonconjugated polysaccharides. We conclude that pneumococcal conjugate vaccines can be of value in protecting asplenic or hyposplenic patients against pneumococcal infections.

Risk of infection and death among post-splenectomy patients

OBJECTIVES

The true incidence of post-splenectomy sepsis remains undetermined.

METHODS

An English literature review on post-splenectomy sepsis was undertaken by means of databases of MEDLINE for the period 1966-96. The data registered included age at splenectomy, indication for splenectomy, incidence of infection and death, interval between splenectomy and infection, and microbial aetiology.

RESULTS

The reports include 19 680 patients having undergone splenectomy with a median follow up of 6.9 years. The incidence of infection after splenectomy was 3.2% and the mortality rate was 1.4%. Only 6942 reports were sufficiently detailed to allow useful analysis. The incidence of infection among children and adults was similar, 3.3% and 3.2%, respectively. However, the death rates among children were higher than adults (1.7% vs. 1.3%). The incidence of infection was highest among patients with thalassemia major (8.2%), and sickle-cell anaemia (7.3%). The highest mortality rates were observed among patients with thalassaemia major (5.1%), and sickle-cell anaemia (4.8%).

CONCLUSION

The incidence of sepsis among post-splenectomy patients is low, however, it carries a high mortality rate especially among children with hematological disorders.

Long-term evaluation of the beneficial effect of subtotal splenectomy for management of hereditary spherocytosis

Clinical manifestations of hereditary spherocytosis (HS) can be abrogated by splenectomy. However, concerns exist regarding exposure of patients to a lifelong risk for overwhelming infections and, to a lesser extent, to vascular complications after total splenectomy. In the search for alternative treatment modalities, we assessed, in a previous pilot study, the potential usefulness of subtotal splenectomy in a small population of patients. During a mean follow-up period of 3.5 years, subtotal splenectomy was shown to be effective in decreasing the hemolytic rate, while maintaining the phagocytic function of the spleen. In the current study, we evaluated the clinical and biologic features of 40 patients with HS who underwent subtotal splenectomy and were monitored for periods ranging from 1 to 14 years. The beneficial effect of subtotal splenectomy included a sustained decrease in hemolytic rate and a continued maintenance of phagocytic function of the splenic remnant. However, mild-to-moderate hemolysis was persistent and accounted for secondary gallstone formation and aplastic crisis in a small subset of patients. Surprisingly, regrowth of the remnant spleen did not seem to have a major impact on the beneficial outcomes of these individuals. Our results suggest that subtotal splenectomy appears to be a reasonable treatment option for management of patients with HS, especially young children.

The diagnosis and management of hereditary spherocytosis

Hereditary spherocytosis (HS) is relatively common in Caucasian populations; most individuals have mild or only moderate disease. There is commonly a family history and a typical clinical and laboratory picture so that the diagnosis is usually easily made without additional laboratory tests. Atypical cases may require measurement of membrane proteins and molecular genetics to clarify the nature of the membrane disorder. It is particularly important to rule out stomatocytosis because splenectomy is contraindicated because of the thrombotic risk. Mild HS can be managed without folate supplements and does not require splenectomy. Moderately and severely affected individuals are likely to benefit from splenectomy, which should be performed after the age of 6 and with appropriate counselling about the risk of infection. In all cases careful dialogue between physician, child and the family is essential. Laparoscopic surgery can result in shorter hospital stay and less pain.

Coinheritance of Gilbert Syndrome Increases the Risk for Developing Gallstones in Patients With Hereditary Spherocytosis

The precocious formation of bilirubinate gallstones is the most common complication of hereditary spherocytosis (HS), and the prevention of this problem represents a major impetus for splenectomy in many patients with compensated hemolysis. Because Gilbert syndrome has been considered a risk factor for gallstone formation, there are reasons for postulating that the association of this common inherited disorder of hepatic bilirubin metabolism with HS could increase cholelithiasis. To test this hypothesis, 103 children with mild to moderate HS who, from age 1, have undergone a liver and biliary tree ultrasonography every year, were retrospectively examined. The 2-bp (TA) insertion within the promoter of the uridine diphosphate-glucuronosyltransferase gene (UGT1A1), associated with Gilbert syndrome, was screened. The risk of developing gallstones was statistically different among the 3 groups of patients: homozygotes for the normal UGT1A1 allele, heterozygotes, and homozygotes for the allele with the TA insertion. Fitting a Cox regression model, in fact, a statistically significant hazard ratio of 2.19 (95% confidence interval: 1.31 to 3.66) was estimated from one to the next of these genetic classes. The individual proneness to form gallstones from TA insertion in the TATA-box of the UGT1A1 promoter should be considered during the follow-up of patients with HS. Although patients with HS were the only ones studied, extrapolating these data to patients who have different forms of inherited (eg, thalassemia, intraerythrocytic enzymatic deficiency) or acquired (eg, autoimmune hemolytic anemia, hemolysis from mechanical heart valve replacement) chronic hemolysis can be warranted.

Northern region asplenia register--analysis of first two years

OBJECTIVES

To assess the feasibility of setting up a register of patients with asplenia within a defined geographical area; to ensure that guidelines on best practice were implemented; to obtain information on antibody levels to pneumococcal capsular polysaccharides and Haemophilus influenzae type b capsular polysaccharide, before and after immunisation and annually thereafter; to raise awareness of risks among clinicians and to offer advice on management.

DESIGN

Prospective recruitment using multiple sources of recruitment. Annual follow up reminders sent from Registration Centre.

SUBJECTS

Population of (old, pre-1995) Northern Health Region: approximately 3.1 million.

MAIN OUTCOME MEASURES

Data were obtained on reasons for asplenia, duration of asplenia, use of prophylactic antibiotics, Medic-Alert bracelets, immunisations, antibody levels, death.

RESULTS

The register was initiated at the beginning of April 1995 and ran to the end of March 1997. After two years of operation, 1111 cases had been registered but the response from some health districts was poor. Major primary causes of asplenia were trauma (264), other surgical (198), lymphoproliferative disease (154), and idiopathic thrombocytopenic purpura (147). There were 664 patients on prophylactic antibiotics, of whom 498 were on continuous antibiotics. Only 18 had any type of warning bracelet. Antibody measurements were carried out at least once on 75% of patients; 306 patients had satisfactory antibody levels on first blood sample in year 1, rising to 405 in year 2; 43 patients failed to make any antibody response to Pneumovax despite multiple immunisations, and three patients failed to respond to Hib vaccine. Sixteen patients with satisfactory antibody levels in year 1 had low levels in year 2 requiring vaccine boosters. Sixteen deaths were reported, two of which were directly attributable to overwhelming sepsis.

CONCLUSIONS

Registration has been successful and has raised awareness of the management of asplenia. Compliance with antibiotic prophylaxis and immunisation was initially poor. A potential high risk group of vaccine non-responders has been identified and poor persistence of pneumococcal antibodies has been identified which is likely to alter approaches to immunisation in asplenic patients.

On the key role of secondary lymphoid organs in antiviral immune responses studied in alymphoplastic (aly/aly) and spleenless (Hox11(-)/-) mutant mice

The role of the spleen and of other organized secondary lymphoid organs for the induction of protective antiviral immune responses was evaluated in orphan homeobox gene 11 knockout mice (Hox11(-/-)) lacking the spleen, and in homozygous alymphoplastic mutant mice (aly/aly) possessing a structurally altered spleen but lacking lymph nodes and Peyer's patches. Absence of the spleen had no major effects on the immune response, other than delaying the antibody response by 1-2 d. In aly/aly mice, the thymus-independent IgM response against vesicular stomatitis virus (VSV) was delayed and reduced, whereas the T-dependent switch to the protective IgG was absent. Therefore, aly/aly mice were highly susceptible to VSV infection. Since aly/aly spleen cells yielded neutralizing IgM and IgG after adoptive transfer into recipients with normally structured secondary lymphoid organs, these data suggest that the structural defect was mainly responsible for inefficient T-B cooperation. Although aly/aly mice generated detectable, but reduced, CTL responses after infection with vaccinia virus (VV) and lymphocytic choriomeningitis virus (LCMV), the elimination of these viruses was either delayed (VV) or virtually impossible (LCMV); irrespective of the dose or the route of infection, aly/aly mice developed life-long LCMV persistence. These results document the critical role of organized secondary lymphoid organs in the induction of naive T and B cells. These structures also provide the basis for cooperative interactions between antigen-presenting cells, T cells, and B cells, which are a prerequisite for recovery from primary virus infections via skin or via blood.

[Hereditary spherocytosis. Course and value of subtotal splenectomy]

BACKGROUND

Effectiveness of subtotal splenectomy, a procedure recently advocated as an alternative treatment to total splenectomy for patients with hereditary spherocytosis (HS), has been evaluated.

METHODS AND PATIENTS

Eighty-eight patients (74 children) with HS were included in this series. Clinical presentations ranged from asymptomatic cases to severe transfusion-dependent forms. Stunting of growth occurred in four cases; chronic fatigue was observed in 30 cases and cholelithiasis in 21 cases. Among the red cell indices measured by laser light scattering on Technicon H2, the most reliable for diagnosis was the abnormal percentage of hyperdense red cells (98% of HS patients). Osmotic gradient ektacytometry, used to measure membrane deformability and impairment of maximal deformability due to a reduction of erythrocyte surface, always showed the characteristic curves of HS.

RESULTS

Subtotal splenectomy was performed in 24 patients leading to a remnant spleen of about 25% of normal for age volume. This decreased the hemolytic rate while adequately sustaining the phagocytic function of the spleen (assessed by percentage of "pitted erythrocytes" and technetium 99n scans of the remnant). However, the observed reduction in hemolytic rate was not as extensive as that observed after total splenectomy (six cases) and subtotal splenectomy did not entirely prevent risk of cholethiasis (three cases).

CONCLUSION

This subtotal splenectomy (+/-cholecystectomy) has to be particularly considered for children with transfusion-dependent forms of HS, in order to obtain the benefits of increased hemoglobin levels without the pending risk throughout life of overwhelming post-splenectomy infections.

Long-term survivors in biliary atresia--findings for a 20-year survival group

Recently, there has been remarkable increase in the survival rate in cases of biliary atresia (BA). However, long-term survivors are as yet a small population. Of the total of 152 patients undergoing surgery for BA during the period from 1969 to 1995 in our institution, 39 of them were operated on more than 20 years ago with follow up for all but one of these, who can no longer be accounted for. Six are still alive, 1 male, and 5 females, two cases being of type I BA, and the other 4 of type III and 1 is unaccounted for. The prognosis of these individuals was clinically evaluated. At the present time, none of them is receiving hospital care, but 3 have experienced sequelae. Two patients required partial splenic embolization (PSE), endoscopic infusion sclerotherapy (EIS), and/or gastroesophageal decongestion and splenectomy (Hassab's operation) (Hassab 1967) for hypersplenism and/or portal hypertension. The other has needed hospital care for recurrent cholangitis. Laboratory investigations revealed a serum total bilirubin (TB) of less than 1.0 mg/100 ml in 3 of the 5 patients for which samples could be obtained, between 1.0 and 2.0 mg/100 ml in 1, and in excess of this in the remaining case. The 1-alanine 2 oxoglutarate aminotransferase (ALT) level was within the normal range in only 1, and was mildly to moderately elevated in 4. The white blood cell count (WBC) was less than 3,000/microliter and the platelet count was less than 10 x 10(4)/microliter in 1, and within the normal ranges in the other 4 patients. The results thus indicate that occult and progressive liver damage may occur in long-term survivors of BA.

Lethal Waterhouse-Friderichsen syndrome in posttraumatic asplenia

We herein report a case of fulminant lethal Waterhouse-Friderichsen syndrome in an elderly female patient seven years after posttraumatic splenectomy. In contrast to various reports, this patient had not been vaccinated against Streptococcus pneumoniae, Neisseria meningitidis, or Haemophilus influenzae, respectively, although infections with these microorganisms are known to cause the main lethal diseases in asplenic patients. Again, we recommend obligatory vaccinations against the mentioned bacteria for it is known that this decreases the risk of fatal septic events in these patients. To optimize prevention, it is imperative to vaccinate patients undergoing splenectomy before discharge from hospital.

Late spontaneous recovery of chronic thrombocytopenia

Five cases are reported of spontaneous remission of chronic childhood thrombocytopenia four or more years after diagnosis. Other than typical features of chronic idiopathic thrombocytopenic purpura there were no obvious markers predictive of late remission, although a slow progressive recovery was common to four of the patients. In light of this experience splenectomy is not recommended in clinically mild thrombocytopenia.

Recurrent traumatic splenic rupture two years after non-operative treatment of splenic trauma

Non-operative and conservative surgical management are now the preferred methods of treatment for blunt splenic trauma in children and adults. These conservative strategies evolved as the risk of late septic complications following splenectomy for trauma became apparent. Although recurrent splenic trauma following conservative management of the ruptured spleen is rare, its surgical management may pose some difficult problems. We present a case in which a second episode of splenic trauma required surgery, two years after the successful non-operative management of the first splenic injury.

Class- and subclass-specific pneumococcal antibody levels and response to immunization after bone marrow transplantation

Immunoglobulin class- and subclass-specific antibodies to a polyvalent pneumococcal capsular polysaccharide vaccine (Pneumovax II) were measured before and after immunization in children, 1 year or more after bone marrow transplantation for a variety of genetic disorders. The median titres of specific IgG, IgG1 and IgG2 pneumococcal antibodies fell significantly (P less than 0.05) from pre-transplantation levels. The levels of pneumococcal antibodies in the patients before immunization were markedly lower than those in control children of comparable age, for antibodies of IgM, IgG, IgG1 and IgG2 classes (P = less than 0.001 in each case). Apart from IgG2 antibodies, the median response to immunization with Pneumovax II was not significantly different from the controls (P greater than 0.05). However, because of the lower pre-immunization levels, the patients did not achieve a high post-immunization-specific antibody titre in any immunoglobulin class or subclass, when compared with normal children. Neither the pre-immunization specific antibody levels nor the response to immunization were affected by splenectomy or the presence of chronic graft-versus-host disease. Immunization of the donor before bone marrow harvest did not influence the level of specific antibody 1 year or more after transplantation. No significant correlation was found between the total serum IgG2, the patients' age at the time of assessment, or time after transplantation, and the IgG2-specific antibody response. The lack of specific antibodies and the poor IgG2 response to pneumococcal antigens may contribute towards the occurrence of infection with Streptococcus pneumoniae in the late post-transplantation period.

Postsplenectomy sepsis and its mortality rate: actual versus perceived risks

A collective critical review of the literature on postsplenectomy sepsis from 1952 to 1987 has been undertaken. The reports cover a cohort of 12,514 patients undergoing splenectomy but of these only 5902 reports were sufficiently detailed to allow a useful analysis. The incidence of infection after splenectomy in children under 16 years old was 4.4 per cent with a mortality rate of 2.2 per cent. The corresponding figures for adults were 0.9 per cent and 0.8 per cent respectively. The present analysis of well documented patients has shown that severe infection after splenectomy for benign disease is very uncommon except in infants (infection rate 15.7 per cent) and children below the age of 5 years (infection rate 10.4 per cent). Many of these reported postsplenectomy infections may have been coincidental. It is also apparent that children contract a different type of infection after splenectomy than adults, predominantly a meningitis which is less frequently fatal. Adults, in contrast, appear to develop a septicaemic type of illness associated with a higher mortality rate. This survey has also shown that children are reported to be more susceptible to pneumococcal sepsis than to infection caused by any other organism. Although the removal of the spleen in otherwise normal people does not appear to be associated with an increased frequency of infection, the presence of a coexistent disorder, notably hepatic disease, can increase the risk substantially.

Penicillin-resistant pneumococci

Penicillin-resistant pneumococci were first reported in Australia in 1967 and appeared in the UK in 1976. Their prevalence is increasing but varies greatly worldwide. The mechanism of resistance lies in the alteration of penicillin-binding proteins. Penicillin-resistant strains are often also resistant to a variety of non-beta-lactam antibiotics. Many different serotypes have been found to be penicillin resistant, type 23 being the most common resistant serotype in the UK. Use of oxacillin discs is recommended for penicillin sensitivity testing, otherwise resistant isolates may escape detection. Treatment of infected patients depends on several factors including the degree of resistance of the infecting strain, the sensitivity to alternative agents and the achievable concentration of antibiotic at the site of the infection. Carriage of penicillin-resistant pneumococci is more common in children, especially the recently hospitalized and those recently exposed to antibiotics. Outbreaks of infection have occurred and various control measures have been suggested in attempts to limit the spread of resistant strains.

Splenectomy for hypersplenism in chronic lymphocytic leukaemia and malignant non-Hodgkin's lymphoma

Between 1 January 1980 and 31 July 1988, 62 patients with chronic lymphocytic leukaemia (CLL) or malignant non-Hodgkin's lymphoma (NHL) were splenectomized for splenomegaly and presumed hypersplenism. All patients except one had splenomegaly (mean (s.d.) weight 1585(872) g, range 150-4300 g) and 34 had massive splenomegaly (greater than 1500 g). Forty-nine patients had platelet counts less than 100 x 10(9)/l and 16 patients had anaemia with haemoglobin levels less than 10 g/dl. White cell counts were less than 3 x 10(9)/l in six NHL patients. Fifteen patients had bicytopenia, and three NHL patients had tricytopenia. The selected group of 62 patients underwent splenectomy largely because of failure to respond to medical therapy (39 patients) or inability to tolerate or start adequate chemotherapy because of very low blood counts (11 patients). There was one postoperative death, and a 29 per cent morbidity rate. The response rate was 89 per cent in the first month after splenectomy and 39 patients (63 per cent) had a continuing complete response with a median follow-up of 26 months (range 3-96 months). Twelve patients (10 with CLL) received no further therapy after splenectomy. Seven patients failed to respond and 15 relapsed after splenectomy. These 22 patients could be distinguished on the basis of: (1) lower average preoperative platelet counts (P less than 0.007), postoperative platelet counts (P less than 0.001), and postoperative rise in platelets (P less than 0.004); (2) lower average spleen weight (P less than 0.052); (3) preoperative chemotherapy (P less than 0.044). However preoperative and postoperative platelet counts were the only two variables selected by stepwise regression analysis (P less than 0.05 and P less than 0.01, respectively). Bone marrow failure did not preclude complete response after splenectomy. Long-term survivors emerged from the group of patients with continuing complete response. Of the seven patients who failed to respond, five died with a median survival of 4 months, and of the 15 patients who relapsed after splenectomy, 13 died, with a median survival of 6 months after relapse and 18 months after splenectomy. Thus, splenectomy may be an effective palliation for both CLL and NHL patients with splenomegaly and hypersplenism.

Cost-effectiveness of splenectomy versus intravenous gamma globulin in treatment of chronic immune thrombocytopenic purpura in childhood

Infusions of intravenous gamma-globulin (IVGG) are an effective, nontoxic therapy for chronic idiopathic thrombocytopenic purpura (ITP) that would be more widely accepted if the therapeutic agent were not so expensive. The costs and outcomes of managing such children with splenectomy and IVGG were modeled with Markov processes. Children unresponsive to one treatment were considered to have received the alternative. The model accounted for spontaneous remissions, therapeutic responses, traumatic events, episodes of sepsis, and operative deaths. For a 10-year-old child with chronic ITP, the strategy of initial treatment with splenectomy had associated costs of $17,000 and a 97.9% ten-year survival rate, whereas the strategy of initial treatment with IVGG had associated costs of $21,000 but a 98.6% survival rate. Each additional life saved by employing the IVGG strategy cost $540,000, or $8,000 per year for a life expectancy of 70 years. Sensitivity analyses demonstrated that for older children the IVGG strategy continued to result in improved survival rates but was more costly than the splenectomy strategy. For younger children, the IVGG strategy dominated, with improved survival rates and lower costs.

Hereditary spherocytosis in the elderly

Five patients with hereditary spherocytosis diagnosed in their seventh to ninth decades of life are presented. These patients are remarkable for absent or mild clinical manifestations of disease. Splenectomy is the recommended treatment for hereditary spherocytosis to avoid the complications of aplastic or hemolytic crisis. When the diagnosis is made in the elderly, the treatment of choice may be careful observation with folic acid supplementation rather than splenectomy. This recommendation is based on the incidence of complications of splenectomy in the elderly in comparison to the severity and incidence of complications from the disease itself.

Splenectomy in the management of haematological disease

Patients, both adults and children, with various haematological disorders who had splenectomy electively in the diagnosis, staging or treatment of their condition during a 15-year period in the Aberdeen hospitals were reviewed. The outcome regarding the disease and the immediate and long-term complications of splenectomy in this group of 185 patients are presented. Splenectomy has an acceptably low morbidity, even in patients with serious haematological disease, in the hands of an experienced surgical team, where there is close co-operation between surgeon and haematologist. Occasionally, late overwhelming infections may occur, despite prophylaxis with penicillin and pneumococcal vaccination. It seems likely that, in their zeal to report such hazards, authors may allow the pendulum against splenectomy to swing too far, in the direction of leaving patients, especially adults, with considerable symptoms and poor health, rather than risk the occasional consequences of the asplenic state.

[Risk of infection following splenectomy]

The problem of a reduced resistance against infections in splenectomized patients is again described on the occasion of one patient who died within a very short time after the beginning of a severe infection. A retrospective study of 150 patients without spleen showed that 2.6% died in a consequence of a severe infection. From the surviving patients 20% complained of very frequent infections. Immunological laboratory data as well as the reaction against recall antigens were reduced in those patients. So not all patients without spleen bear a high risk with regard to severe infections. In spite of this fact surgeons should try to preserve the spleen even in adults.