Possible pathogenetic role of capsular antigens in fulminant pneumococcal disease with disseminated intravascular coagulation (DIC)

Fulminant pneumococcal infection

Fulminant pneumococcal infection is a fatal pneumococcal infection that tends to occur in immunocompromised hosts, such as patients who are asplenic or on immunosuppressant therapy. We experienced a case of a 73-year-old Japanese man with a medical history of coronary stent implantation and catheter ablation for atrial flutter who presented with dyspnoea at rest. The patient was diagnosed with streptococcal pneumonia based on a urine antigen test and CT. Despite the use of effective antibiotics and systemic therapies, his clinical course was rapidly progressive and he died 18 h after admission. This case of fulminant pneumococcal infection is reported along with the autopsy findings.

Autopsy cases of fulminant bacterial infection in adults: clinical onset depends on the virulence of bacteria and patient immune status

To assist physicians in recognizing the potentially fatal onset of symptoms in cases of fulminant bacterial infection, we analyzed 11 autopsy cases of such infection (four caused by Streptococcus pneumoniae, four by S. pyogenes, one by S. dysgalactiae subsp. equisimilis, one by Staphylococcus aureus, and one by Vibrio vulnificus). Clinicohistopathologic features were evaluated. All patients experienced sudden onset of hypotension and multiple organ failure, leading to unexpected death. Blood culture confirmed bacteremia. The main chief complaints were gastrointestinal symptoms (45%) and limb pain (36%). All had an underlying chronic illness (82%), e.g., a hematologic disorder (36.3%) or liver cirrhosis (27.2%). Necrotizing fasciitis occurred in only 55% of cases, with none involving pneumococcal infection. Laboratory tests typically showed C-reactive protein elevation but without leukocytosis, indicating a high-level inflammatory state. In ten cases, death was attributed to circulatory collapse due to sepsis; severe pulmonary congestion and hemorrhage were present in these cases. The onset of fulminant bacterial infection depends on both virulence of the bacterium and status of the host defense system.

Sudden death caused by fulminant bacterial infection: background and pathogenesis of Japanese adult cases

OBJECTIVE

To analyze a risk factor for the onset of fulminant bacterial infection.

PATIENTS AND METHODS

Nine unexpected acute death cases were clinicopathologically analysed. All cases represented the sudden onset of shock symptom, led to acute death within a few days, and later bacteremia was identified. Pathogens were Streptococcus pneumoniae (S. pneumoniae) (5 cases), group A beta Hemolytic Streptococcus pyogenes (S. pyogenes) (3 cases), and Vibrio vulnificus (V. vulnificus) (1 case).

RESULTS

Seven of the nine patients had underlying chronic illness. S. pneumoniae infection was associated with splenic dysfunction, and group A beta Hemolytic S. pyogenes and V. vulnificus infections were associated with alcoholic liver injury. Group A beta hemolytic S. pyogenes and V. vulnificus infections involved necrotizing fasciitis, and alcoholic liver cirrhosis was confirmed in two of the four patients.

CONCLUSION

Despite the different type of bacteria, the onset of fulminant bacterial infection depended upon depressed bacterial phagocytosis in the liver or spleen. Underlying chronic illnesses should be identified as a predisposing common risk factor. It is important to understand the relations between underlying chronic illness and the onset of fulminant infection.

Rapidly progressive fatal pneumococcal sepsis in adults: a report of two cases

We report two cases of a rapidly progressive fatal overwhelming pneumococcal infection. Patient 1 was a 67-year-old man with a 24-h history of fever and malaise and was transferred to our department. He was severely ill, tachypneic, and felt a chill. A purpuric discoloration with ecchymosis of the skin was noted over the body. The chest X-ray findings demonstrated thickening of the bronchovascular bundle in the right lower lung field, which later revealed the presence of bronchopneumonia. Laboratory studies revealed the presence of metabolic acidosis and disseminated intravascular coagulation. After presentation, rapid deterioration occurred followed by cardiopulmonary arrest. Despite cardiopulmonary resuscitation, the patient died only 3 h after presentation. The isolates from the patient's blood revealed penicillin-susceptible Streptococcus pneumoniae, serotype 4. Patient 2 was a 30-year-old woman with a prior history of uneventful pregnancies was transferred to our department with a 2-day history of fever, nausea, headache, and malaise. Although she was in the 19th week of pregnancy at the time, she suffered a miscarriage just prior to admission. Upon presentation to our department, she demonstrated unstable vital signs, diminished consciousness, anuria, and icterus. Purpuric discoloration with ecchymosis of the skin was noted in over most of her body, including the distal extremities. The chest X-ray findings were close to normal. Initial laboratory studies revealed the presence of severe metabolic acidosis and disseminated intravascular coagulation with multiple organ failure. Despite aggressive cardiopulmonary support, normal neurological responses disappeared on the 2nd day following admission and the patient died on the 16th day after admission. The patient's isolates from blood and vaginal swabs both later revealed penicillin-susceptible Streptococcus pneumoniae, serotype 12F. The presentation of rapidly progressive septic shock should raise the treating physician's suspicion of overwhelming pneumococcal infection, which has limited management options.

Clinicopathological findings in fulminant-type pneumococcal infection: Report of three autopsy cases

Reported herein are three autopsy cases of fulminant-type pneumococcal sepsis with disseminated intravascular coagulation (DIC) resulting in death within a few days of onset of symptoms. Two of the three patients had previously had a splenectomy because of a hematological disorder. None of the patients had received pneumococcal vaccination. On post-mortem every organ had congestion as well as bleeding. Interestingly, severe inflammation of the alveoli was absent despite the sepsis. The cause of death was rapidly progressive pneumococcal sepsis leading to DIC and circulatory failure, which appeared to cause pulmonary congestion and hemorrhage without pneumonia. It is important to understand the pathogenesis of fulminant-type pneumococcal infection because it is life-threatening for compromised hosts.

Fatal pneumococcal Waterhouse-Friderichsen syndrome

There have only been six deaths reported in the English literature due to disseminated intravascular coagulation and Waterhouse-Friderichsen syndrome complicating pneumococcemia in otherwise healthy persons with normal spleens. Four of these deaths occurred in children and two in adults. A case of fulminant pneumococcemia complicated by disseminated intravascular coagulation and Waterhouse-Friderichsen syndrome in an otherwise healthy adult with a normal spleen is presented. The case is typical of the course of fulminant pneumococcal sepsis and highlights some of the difficulties experienced by rural general practitioners and rural retrieval services. Mechanisms by which Pneumococcus can elicit fulminant sepsis are discussed, although there is no explanation as to why this may occur in the setting of normal splenic function.

Rupert Waterhouse and Carl Friderichsen: adrenal apoplexy

The Waterhouse-Friderichsen (WFS) syndrome, also known as purpura fulminans, is described as acute hemorrhagic necrosis of the adrenal glands and is most often caused by meningococcal infection. This clinical entity is more frequently seen in the pediatric than the adult population and is associated with a high morbidity and mortality. The initial presenting complaints for patients with the WFS usually include a diversity of nonspecific, vague symptoms such as cough, dizziness, headache, sore throat, chills, rigors, weakness, malaise, restlessness, apprehension, myalgias, arthralgias, and fever. These symptoms are usually abrupt in their onset. Petechiae are present in approximately 50-60% of patients. The clinical diagnosis of WFS may be relatively straightforward or extremely challenging. Patients who appear in the initial and nontoxic-appearing stage without any skin lesions may be difficult to distinguish from a benign viral illness. When a patient presents with fever and petechiae, WFS must be considered, even when the patient has a non-toxic appearance. Due to the rapid progression and often devastating consequences, therapy should be instituted as soon as the diagnosis is suspected.

Sepsis and adrenal function

In the setting of sepsis, adrenal function can be difficult to evaluate. Cortisol levels, normally elevated by the stress of sepsis, are occasionally reduced, signifying possible adrenal dysfunction. Even elevated cortisol levels do not assure that adrenal reserve is adequate and may in fact portend a preterminal state. Bilateral adrenal hemorrhage leading to adrenal insufficiency is one complication of the sepsis syndrome. This endocrine rounds illustrates the importance in considering adrenal insufficiency and adrenal hemorrhage in patients with overwhelming sepsis while discussing the pathophysiology, clinical presentation, and therapeutic implications of this dire complication.

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.

Immune complex-induced disseminated intravascular coagulation (DIC). An experimental study

Disseminated intravascular coagulation (DIC) was induced in rabbits by administration of antibody and antigen. The rabbits were sensitized passively by i.v. injection of antiferritin antiserum and challenged simultaneously by an i.p. inoculation of ferritin. After the challenge, circulating white blood cells, platelets and plasma fibrinogen levels showed an early fall, reaching minimum values at 3, 10 and 6 h, respectively. Fibrin thrombi appeared first at 2 h, reached a maximum at 5-7 h, and had mostly disappeared by 24 h. Formation of fibrin thrombi was frequent in the lung, liver, kidney and spleen. Early morphological changes included neutrophilic infiltration and accumulation of platelets in capillaries. Ferritin-antiferritin complexes were noted among fibrin thrombi or phagocytized by reticuloendothelial cells and neutrophils. The capacity of Kupffer cells to remove circulating immune complexes was saturated transiently; at this time fibrin thrombosis in various organs was most widespread and severe. It seems likely that formation of antigen-antibody complexes in the microcirculation initiates activation of platelets and neutrophils with subsequent release of mediators responsible for triggering DIC. Activation of complement was another possible factor inducing the reaction. In addition, blockade of the reticuloendothelial system promotes the progression of DIC. It is considered that the methods described constitute a useful model for further elucidation of immune complex-induced DIC.

Metastatic pneumococcal endophthalmitis: report of two cases and review of literature

Two patients with pneumococcal bacteraemia complicated by endophthalmitis are described. While this condition appears to have been relatively common in the preantibiotic era, a review of the literature since 1950 only identified six additional case reports. Analysis of these eight cases reveals two patterns: unilateral disease in six patients and bilateral disease with simultaneous onset in two patients. The potential pathogenic mechanisms--direct bacterial invasion or immunologically mediated processes--are discussed in relation to these clinical presentations. The critical importance of seeking ophthalmological advice early in the course of the disease is emphasised, as the risk of visual loss with systemic antimicrobials alone is very high, particularly if the infective process involves the vitreous humour.

Pneumococcal Waterhouse-Friderichsen syndrome despite a normal spleen

A previously fit 56 year old female presented with a rapidly progressive and fatal pneumococcal septicaemia with disseminated intravascular coagulation. Post-mortem studies confirmed a Waterhouse-Friderichsen syndrome and revealed an anatomically normal spleen; intracellular diplococci were seen within splenic macrophages providing evidence of normal splenic function. This appears to be only the second case of Waterhouse-Friderichsen syndrome due to pneumococcal septicaemia in a patient with a normal spleen.

Isolation and characterization of circulating immune complexes from patients with pneumococcal pneumonia

Circulating immune complexes (CIC) were isolated from serum samples from patients with bacteremic and nonbacteremic pneumococcal pneumonia. Overall, 63% (26 of 41) of patients with pneumococcal pneumonia had elevated levels of immunoglobulin G (IgG)-containing CIC. IgM-containing CIC were identified in samples from only three patients. Serum samples from nonbacteremic patients contained significantly higher levels of IgG-containing CIC (96.6 +/- 111.7 micrograms/ml) than did samples from bacteremic patients (31.7 +/- 26.9 micrograms/ml) during week 1 in hospital (P less than 0.05). Immune complexes levels did not correlate with IgG concentrations in serum or anticapsular antibody levels. Immune complexes from nonbacteremic patients had sedimentation coefficients of greater than 19s by density gradient ultracentrifugation. In contrast, CIC from bacteremic patients had smaller coefficients, of between 9s and 14s. Pneumococcal capsular antigens were identified in concentrated dissociated CIC from both patient groups by counterimmunoelectrophoresis.

Comparison of immunological methods for diagnosis of pneumococcal pneumonia in biological fluids

Five immunological tests were evaluated for their ability to detect Streptococcus pneumoniae antigen in serum and urine simultaneously as a means of rapid diagnosis in 40 patients with bacteremic or non-bacteremic pneumococcal pneumonia or pneumonia with other etiologies. Serum and urine were screened in parallel with counterimmunoelectrophoresis (CIE), two commercial latex agglutination kits - the Slidex pneumokit (LA-SPK) and the Bactigen Streptococcus pneumoniae kit (LA-Bac) - the coagglutination Phadebact Pneumococcus test (CoA) and a newly developed enzyme-linked immunosorbent assay (ELISA) containing the immunoglobulin G fraction from rabbit pneumococcal antiserum. The detection rate for accumulated serum in bacteremic patients was 18% for LA-Bac, 24% for CIE, 47% for LA-SPK and CoA and 76% for ELISA, whereas antigenuria was present in only 29% for LA-SPK, 24% for CIE, 19% for CoA, 14% for LA-Bac and 5% for ELISA. Detection by ELISA of pneumococcal antigen in severely ill patients can predict bacteremia and rapidly confirm the diagnosis of pneumococcal pneumonia if sputum and results of blood cultures are not available.

Pneumococcal intracellular killing is abolished by polysaccharide despite serum complement activity

Normal human serum absorbed at 0 degrees C with pneumococcal serotype 1, 12, or 25 lost the ability to support polymorphonuclear leukocyte intracellular killing of some pneumococcal serotypes even if immunoglobulin was provided. The absorbed serum contained no organisms but had residual polysaccharide when measured by counterimmunoelectrophoresis against type-specific antisera. The influence of pneumococcal polysaccharide (PPS) on serum support of intracellular polymorphonuclear leukocyte killing was evaluated. Normal human serum was mixed with PPS serotype 1, 12, or 25 at 0 degrees C for up to 120 min and then used as the opsonic source in standard phagocytic killing assays with serotype 1, 12, or 25. Immediately after mixing, each serum combined with PPS serotype 1, 12, or 25 supported killing of all serotypes tested. With increasing time at 0 degrees C with serotype 1 PPS, serum exhibited a marked progressive decline in killing of serotype 25, a similar but less marked impairment in killing of serotype 12, and essentially no impairment for serotype 1. Serum treated with type 25 PPS did not support killing of type 25, but allowed normal killing of types 1 and 12. Incubation with type 12 PPS impaired opsonization of types 12 and 25, but not 1. Addition of PPS-specific antisera did not restore killing. Residual serum hemolytic activity of classic and alternative complement pathways was not reduced below opsonizing levels after 120 min at 0 degrees C. Furthermore, PPS treatment of normal human serum did not alter the attachment or ingestion of 14C-labeled pneumococci by polymorphonuclear leukocytes. Some serotypes of PPS reacted slowly with serum at 0 degrees C, diminishing its ability to support intracellular killing of pneumococci despite serum hemolytic complement activity. Phagocytosis was not inhibited. Specific antibody did not overcome inactivation. Different requirements for the inactivated factor among serotypes may be a characteristic related to organism virulence.

Antigen detection in the diagnosis and in the prognostic assessment of bacterial pneumonias

Sputum cultures are not helpful in the immediate management of patients with bacterial pneumonia. Sputum Gram stains may provide a presumptive identification of an etiologic agent; this procedure, however, is insensitive (approximately 50%). Consequently, during the last decade, other more sensitive and specific methods of providing a rapid etiologic diagnosis have been sought. This article discusses data on antigen detection in various body fluids by counterimmunoelectrophoresis and agglutination tests. Results from our own laboratory as well as those reported in the literature are presented. The best estimates of antigen detection rates, by the most sensitive assays, in pneumococcal pneumonia, are as follows: serum, 45%-80%; urine, 50%-64%; and sputum, 75%-100%. There is less information for Haemophilus, Klebsiella, and Pseudomonas pneumonias, but the diagnostic yield is approximately 50%-100%. Data will also be presented on the association between free and complexed antigens and morbidity and mortality in pneumococcal pneumonia. Indicators of morbidity discussed include disseminated intravascular coagulation, duration and severity of illness, and occurrence of nephritis.

Relationships between alternative complement pathway activation, C-reactive protein, and pneumococcal infection

In the absence of specific antibody, opsonization of Streptococcus pneumoniae may be mediated by the alternative complement pathway (AP) or by C-reactive protein (CRP) via C1 binding. To determine the role of these mechanisms in pneumococcal (PNC) disease, we studied 19 patients with differing severities of PNC infection. C4 and CRP levels and zymosan-induced consumption of 50% hemolytic complement (CH50) were measured in specimens obtained acutely and then weekly. In patients with complicated illness, the modified mean CH50 in acute sera was 178 +/- 57 U/ml, significantly lower than the mean CH50 of 331 +/- 80 U/ml in patients with uncomplicated illness (P less than 0.05). The values of the two groups on a given day approximated each other on days 7, 14, and 23. Consumption of complement by zymosan was also lower in acute sera of patients with complicated illness, with a mean value of 19 +/- 18 U/ml compared with 58 +/- 30 U/ml in those with uncomplicated illness (P less than 0.05). This difference was also seen on day 7 (P less than 0.05). Disease involving lower-numbered PNC serotypes (less than 10) correlated with reduced availability of AP factors in acute sera, independent of illness severity. Mean CRP levels were inversely related to zymosan-induced complement activation in patients with complicated illness. These data suggest that in vivo depletion of AP factors is significantly greater in patients with complicated illness and is associated with high CRP levels. CRP may enhance AP activation via C3 convertase generation and function with it as a preantibody host defense mechanism.

Postsplenectomy sepsis 10 years or more after operation

Three new cases (two fatal) of postsplenectomy sepsis occurring 14, 25, and 26 years after operation for hereditary spherocytosis are described. There are now 25 cases in the published work in which this complication occurred 10 or more years after operation, 14 of which were fatal. The mean age of onset is 37 years. The features of the disease are similar to those seen in other postsplenectomy infections, and pneumococcal infection was responsible in 19 cases (76%). The major predisposing illnesses were trauma, hereditary spherocytosis, and idiopathic thrombocytopenia.

Purpura in occult pneumococcal bacteremia

An unusual case of occult pneumococcal bacteremia is reported. A 4-month-old female presented with ascending purpura on the lower extremities as the only abnormal physical finding. All initial laboratory studies were normal; however, Streptococcus pneumoniae serotype 6 was cultured from her blood within 18 hours and subsequently from the nasopharynx. This is the first reported case in humans of occult pneumococcal bacteremia presenting with the primary clinical finding of purpura. This entity has a well defined animal model in mice.

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.

Complement in pneumococcal infections with varying degrees of severity

Complement component levels (Clq, Cls, C4, C3, factor B and properdin) and C1 subcomponent complexes (C1r-C1s, C1-r-C1-, C1-r-C1-s-C1 inactivator, 1A) were studied in 16 adults with pneumococcal infections varying severity. Patients with fulminant disease and signs of septic shock showed pronounced hypocomplementemia. In patients with pneumococcal pneumonia or meningitis elevated levels of C1-r-C1-s-C1- IA complexes indicated activation of C1, despite normal levels of C1q, C1s, C4 and C3. Moderately decreased properdin values suggested involvement of the alternative pathway. In adults with pneumococcal otitis no changes in the complement profile was found. In contrast, pronounced aberrations of the C1 subcomponents were earlier demonstrated in children with otitis.

Alterations in serum opsonic activity and complement levels in pneumococcal disease

Pneumococcal opsonic activity and concentrations of pneumococcal capsular polysaccharide antigen, C3, C4 factor B, C3 and factor B breakdown products were measured in the serum obtained acutely from 12 patients with serious pneumococcal disease. One patient showed markedly reduced pneumococcal opsonic activity, borderline-low C3, and the presence of C3 and factor B breakdown products and died. Although eight additional patients showed depressed levels of C3 or C4 or the presence of C3 or factor B breakdown products, none had reduced pneumococcal opsonic activity. All of the three remaining patients had normal opsonic activity and C3 and C4 levels. Covalescent serum was obtained from eight patients; six had normal C3 and C4 levels, and two had persistent C4 depression. These data show that complement is activated during pneumococcal disease and suggest that extensive complement activation may impair pneumococcal opsonic activity in certain patients and thereby compromise an important host defense mechanism.

Pneumococcal disease and its prevention with polyvalent pneumococcal polysaccharide vaccines--a review

Polyvalent pneumococcal polysaccharide vaccines have been shown to be safe, immunogenic and efficacious and are becoming available for use in patients at high risk of developing pneumococcal infections. Precise estimates of the role of the pneumococcus in human respiratory disease are difficult to obtain, as this organism is also a frequent commensal of the upper respiratory tract; and as the optimal techniques for the identification and proof of its role are not widely used. Nevertheless, the pneumococcus remains the principal cause of adult pneumonia and paediatric otitis media, and is also an important cause of death from bacteremia and meningitis. At present it seems likely that in Australia these vaccines will be most useful amongst people over the age of 50 years, those with chronic systemic disease, alcoholics, splenectomized individuals and disadvantaged groups such as Australian aborigines, all of whom are particularly susceptible to pneumo-coccal bacteremia which has a considerable mortality rate. The possibility of preventing pneumococcal otitis media in childhood is still being evaluated. Studies of the role played by the various pneumococcal serotypes in Australian populations are urgently needed.

Splenic function: normal, too much and too little

This review is concerned with normal splenic function, mechanisms and consequences of splenomegaly, hypersplenism, the medical indications for splenectomy and the various aspects of hyposplenism. The potential probelm of lethal septicemia in hyposplenic or asplenic patients is also considered.

Sepsis and congenital asplenia

Fifty-nine children with congenital asplenia were reviewed for episodes of severe infection. Seven children had isolated asplenia and 52 had asplenia associated with complex congenital heart disease (asplenia syndrome). A control group of eusplenic children with comparable cardiac lesions were assembled and used for comparative statistical analysis. There were 16 instances of documented sepsis among 59 children (27%). In those less than six months of age, the invading organism was usually gram-negative (Escherichia coli or Klebsiella). In children six months of age or older, the infecting organism was usually a pneumococcus or H. influenzae. When those with asplenia syndrome were compared to the control population, the former group had a significantly greater incidence of sepsis. Children with asplenia syndrome who survived the first month of life were at greater risk of dying from sepsis than from their heart disease. It is recommended that prophylactic antibiotics be administered to children with congenital absence of the spleen, commencing at three months of age, to be continued indefinitely.

Overwhelming postsplenectomy infection

One of the more intriguing aspects of the spleen is the protection against certain bacterial infections afforded by its unique vascular and immune function. There have been extensive clinical surveys which indicate an incidence of overwhelming postsplenectomy infection (OPSI) above that of the disease for which the splenectomy was done. In the absence of the spleen, either congenital or subsequent to surgical removal, this overwhelming sepsis has a 50% case fatality rate. The most common infective organism has been Diplococcus (tstreptococcus) pneumoniae (D. pneumoniae). Intensive investigations indicated loss of phagocytic function of the spleen, depression of serum IgM levels, a possible suppression of the lymphocyte responsiveness, and changes in opsonin-alternative complement system as potential causes of OPSI. Preventive measures against OPSI include trials of prophylactic Phenoxymethyl Penicillin (penicillin) and pneumococcal vaccine.

Non-bacterial thrombotic endocarditis: clinicopathologic correlations

Sixty-five cases of nonbacterial thrombotic endocarditis (NBTE) were discovered at autopsy during a 10 year period--an incidence of 1.6 per cent in the adult autopsy population. In 51 cases, one or more malignant neoplasms were associated; adenocarcinoma represented the most frequent histologic type of related neoplasm. Coagulation abnormalities suggestive of disseminated intravascular coagulation (DIC) were present in 18.5 per cent of the cases. It is possible that both the valvular and peripheral intravascular thromboses in at least some cases of NBTE represent the abnormal coagulation of DIC. Arterial thrombosis with infarction occurred in many peripheral organs. Splenic and renal were most frequent, but cerebral and cardiac consequences were the most significant.

Effects of meningococcal and Escherichia coli capsular polysaccharides on human and dog platelet aggregation in vitro

Highly purified capsular polysaccharides from groups A, B, and C meningococci and from two strains of Escherichia coli did not aggregate human or dog platelets in vitro. Nor was there any detectable effect on platelet aggregation induced by adenosine diphosphate (ADP), epinephrine, or collagen. The results do not support the hypothesis that capsular polysaccharides are involved in the pathogenesis of thrombocytopenia often seen in severe infections with these bacteria.