Arterial immune protein expression demonstrates the complexity of immune responses in Kawasaki disease arteritis

A more complete understanding of immune-mediated damage to the coronary arteries in children with Kawasaki disease (KD) is required for improvements in patient treatment and outcomes. We recently reported the transcriptional profile of KD coronary arteritis, and in this study sought to determine protein expression of transcriptionally up-regulated immune genes in KD coronary arteries from the first 2 months after disease onset. We examined the coronary arteries of 12 fatal KD cases and 13 childhood controls for expression of a set of proteins whose genes were highly up-regulated in the KD coronary artery transcriptome: allograft inflammatory factor 1 (AIF1), interleukin 18 (IL-18), CD74, CD1c, CD20 (MS4A1), Toll-like receptor 7 (TLR-7) and Z-DNA binding protein 1 (ZBP1). Immunohistochemistry and immunofluorescence studies were performed to evaluate protein expression and co-localization, respectively. AIF1 was expressed transmurally in KD arteritis and localized to macrophages and myeloid dendritic cells. CD74, which interacts with major histocompatibility complex (MHC) class II on antigen-presenting cells, localized to the intima-media. CD1c, a marker of myeloid dendritic cells, was expressed in a transmural pattern, as were IL-18 and CD20. ZBP1 and TLR-7 were up-regulated compared to controls, but less highly compared to the other proteins. These findings provide evidence of antigen presentation and interferon response in KD arteritis. In combination with prior studies demonstrating T lymphocyte activation, these results demonstrate the complexity of the KD arterial immune response.

CD84 is markedly up-regulated in Kawasaki disease arteriopathy

The major goals of Kawasaki disease (KD) therapy are to reduce inflammation and prevent thrombosis in the coronary arteries (CA), but some children do not respond to currently available non-specific therapies. New treatments have been difficult to develop because the molecular pathogenesis is unknown. In order to identify dysregulated gene expression in KD CA, we performed high-throughput RNA sequencing on KD and control CA, validated potentially dysregulated genes by real-time reverse transcription-polymerase chain reaction (RT-PCR) and localized protein expression by immunohistochemistry. Signalling lymphocyte activation molecule CD84 was up-regulated 16-fold (P < 0·01) in acute KD CA (within 2 months of onset) and 32-fold (P < 0·01) in chronic CA (5 months to years after onset). CD84 was localized to inflammatory cells in KD tissues. Genes associated with cellular proliferation, motility and survival were also up-regulated in KD CA, and immune activation molecules MX2 and SP140 were up-regulated in chronic KD. CD84, which facilitates immune responses and stabilizes platelet aggregates, is markedly up-regulated in KD CA in patients with acute and chronic arterial disease. We provide the first molecular evidence of dysregulated inflammatory responses persisting for months to years in CA significantly damaged by KD.

Angiogenesis in fatal acute Kawasaki disease coronary artery and myocardium

Angiogenesis has been shown to be dysregulated in coronary artery (CA) aneurysms in the chronic phase of Kawasaki disease (KD). Neovascularization may occur in inflammatory-related vascular diseases because many angiogenesis mediators are secreted by inflammatory cells. We hypothesized that inflammation of the acute KD CA aneurysm could lead to dysregulation of angiogenesis mediators and subsequent neovascularization. To investigate this hypothesis, acute fatal KD cardiac tissues were immunostained for angiogenic inducers and inhibitors. Microvessel density was determined and the degree of inflammation assessed. Marked inflammation and angiogenesis were found in acute KD CA aneurysms and myocardium, with the highest microvessel density seen in patients who died 2-3 weeks after onset of the disease. Expression of proangiogenic proteins was higher than expression of inhibitors in KD CA aneurysms and myocardium. Angiogenesis mediators were localized to inflammatory cells in the myointima, adventitia, and myocardium. We conclude that significant neovascularization occurs in acute KD CA aneurysms and myocardium much sooner after onset of the disease than has been previously reported, that multiple angiogenesis factors are involved, and that dysregulation of angiogenesis likely contributes to KD vasculopathy.

Recent developments and controversies in Kawasaki disease

In the developed world, Kawasaki disease is currently the leading cause of pediatric acquired heart disease. To date, the etiologic agent remains unknown. Many hypotheses regarding the etiology exist, and debate continues as to whether the inflammatory response of Kawasaki disease results from a superantigen or a conventional antigen. A variety of growth factors, proteinases, and cytokines have been identified that are involved in the pathogenesis of coronary artery disease in Kawasaki disease. These findings are leading to novel treatment strategies in Kawasaki disease, including platelet glycoprotein receptor inhibitors and monoclonal antibody to tumor necrosis factor-alpha. The role of corticosteroids remains controversial, and ongoing clinical trials are evaluating its efficacy. Additional studies have focused on newer non-invasive methods of evaluating children with coronary artery disease as alternatives to coronary catheterization. We review recent developments and controversies in exploring the etiology, pathogenesis, diagnosis, and management of Kawasaki disease.

Coronary artery bypass grafting for Kawasaki disease

Five patients with a history of Kawasaki disease underwent coronary revascularization at Children's Memorial Hospital (1988-2000). Acute disease occurred at 11 weeks to 5 years of age and revascularization procedures were performed at 8 months to 12 years (mean 6 years; interval from disease onset 5 months to 9 years). Surgical indications included abnormal stress testing with angiographic confirmation of severe coronary artery stenosis (n = 3), severe coronary artery stenosis with echocardiographic evidence of intracoronary thrombus (n = 1), and ischemic electrocardiogram changes and ventricular tachycardia during angiography (n = 1). All revascularization procedures used internal thoracic arteries including one free internal thoracic artery graft. There were no postoperative deaths (follow-up 1 month to 11 years). All patients are asymptomatic. One patient developed myocardial ischemia 4 years postoperatively with occlusion of the circumflex coronary artery (not previously grafted). This was treated successfully with percutaneous coronary angioplasty and stent placement. All grafts are patent with the exception of a single right internal thoracic artery graft which underwent involution 30 months postprocedure with concurrent recannulization of the right coronary artery. Coronary revascularization should be considered in the young patient with severe coronary abnormalities secondary to Kawasaki disease.

CD8 T lymphocytes and macrophages infiltrate coronary artery aneurysms in acute Kawasaki disease

The pathogenesis of coronary arterial inflammation in acute Kawasaki disease (KD) is unclear. To test the hypothesis that the KD vascular lesion is an activated T lymphocyte-dependent process, immunohistochemical studies were done on coronary artery aneurysms from 8 fatal acute KD cases by using antibodies to CD45RO (activated or memory T lymphocyte), CD8 (cytotoxic T lymphocyte), CD4 (helper T lymphocyte), HAM56 (macrophage), and CD20 (B lymphocyte). Acute KD coronary arteritis was characterized by transmural infiltration of CD45RO T lymphocytes with CD8 T lymphocytes predominating over CD4 T lymphocytes. Macrophages were present primarily in the adventitial layer; B lymphocytes were notably absent. These data lend support to the hypotheses that KD results from infection with an intracellular pathogen, such as a virus, whose antigens are presented by major histocompatibility complex class I molecules, and that CD8 T lymphocytes and macrophages are important in the pathogenesis of KD coronary aneurysms.

Surface and cytoplasmic immunoglobulin expression in circulating B-lymphocytes in acute Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis of young childhood predominantly affecting the coronary arteries. IgA plasma cells have been found to infiltrate vascular and nonvascular tissues in fatal acute KD. To determine whether IgA B-lymphocytes were increased in the peripheral blood of patients with KD, we performed three-color flow cytometry to detect surface and cytoplasmic immunoglobulin expression (IgA, IgM, IgD, and IgG) of peripheral B-lymphocytes in KD patients during the acute, subacute, and convalescent stages of illness and in age-matched febrile and afebrile pediatric controls. Surprisingly, absolute numbers of B-lymphocytes expressing IgA were found to be significantly lower in peripheral blood of acute KD patients compared with febrile and afebrile pediatric controls. These findings indicate that IgA plasma cells are not present in KD tissue as a result of excess numbers of these IgA B-lymphocytes in peripheral blood. We speculate that IgA B-lymphocytes are selectively withdrawn from the peripheral circulation into KD target tissues as part of a specific IgA immune response.

Staphylococcus lugdunensis: an emerging cause of ventriculoperitoneal shunt infections

Staphylococcus lugdunensis, a coagulase-negative staphylococcus first described in 1988, has gained recognition as an organism with considerable pathogenic capability in adults. In contrast to the indolent presentation characteristic of other coagulase-negative staphylococci, S. lugdunensis infections resemble the aggressive behavior of Staphylococcus aureus. Although the organism has been isolated from a wide variety of infections in adults, it is a very rare cause of pediatric infections. We describe the first two pediatric patients who developed ventriculoperitoneal shunt infections caused by S. lugdunensis. These cases suggest that coagulase-negative staphylococci should be identified to the species level and that, if S. lugdunensis is identified, greater morbidity compared to that associated with other coagulase-negative staphylococcal shunt infections should be anticipated. A longer course of therapy is recommended for S. lugdunensis infections.

Recent developments in Kawasaki disease

Kawasaki disease is now being recognized as the leading cause of acquired heart disease in children in North America and Japan. This review discusses the recent developments and controversies in Kawasaki disease. Increasing evidence has supported an infectious etiology for Kawasaki disease; however, the debate continues as to whether the inflammatory response results from a conventional antigen or a superantigen. Recent immunohistochemistry findings suggest many vascular growth factors then play a role in the formation of the coronary artery lesions. Many studies have focused on the identification and therapy for patients resistant to conventional therapy, as well as the long-term prognosis of Kawasaki disease survivors. The recent advances in Kawasaki disease are helping to provide some clues in the etiology, pathogenesis and therapy for Kawasaki disease.

Nosocomial infection rates in US children's hospitals' neonatal and pediatric intensive care units

BACKGROUND

Few data are available on nosocomial infections (NIs) in US children's hospitals' neonatal or pediatric intensive care units. The Pediatric Prevention Network (PPN) was established to improve characterization of NIs in pediatric patients and to develop and test interventions to decrease NI.

METHODS

Fifty participating children's hospitals were surveyed in 1998 to determine NI surveillance methods used and neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU) 1997 NI rates. Data were collected on standardized forms and entered and analyzed by using SPSS for Windows.

RESULTS

Forty-three (86%) children's hospitals returned a completed questionnaire. All reported conducting NICU and PICU NI surveillance (range, 2-12; median, 12 months). Nineteen children's hospitals provided NICU NI rate data in one or more formats suitable for comparison. Denominators used for NICU NI rate calculations varied: 17 reported overall NI by patient-days; 19 reported bloodstream infection (BSI) by central venous catheter (CVC)-days, and 8 reported BSI by patient-days. Sixteen (16) children's hospitals reported NICU BSI data stratified by CVC-days and birth-weight cohort, and ventilator-associated pneumonia (VAP) by birth weight cohort was reported by 12. Twenty-four children's hospitals reported PICU NI rate data in one or more formats suitable for comparison. Denominators used for PICU NI rate calculations also varied: 20 reported overall NI rates by patient-days; 23 reported BSI rates by CVC-days, and 10 reported BSI rates by patient-days; 24 reported VAP by ventilator-days; and 15 reported urinary tract infections (UTIs) by urinary catheter-days. Median overall NI rates per 1000 patient days were 8.9 in NICUs and 13.9 in PICUs. Median NICU NI device-associated rates by birth weight (>2500 g, 1501-2500 g, 1001-1500 g, and </=1000 g) were BSI 4.4, 4.7, 8.9, and 12.6, and VAP 0.9, 1.1, 4.9, and 3.5, respectively. Median PICU NI rates per 1000 device days were 6.5 for BSI; 3.7 for VAP; and 5.4 for UTI.

CONCLUSIONS

The number of months that NICU or PICU NI surveillance was conducted varied among hospitals. Reported NICU and PICU NI rates varied by hospital; some reported overall NI rates, and others focused on one or more particular sites of infection (eg, BSI or pneumonia). Many did not provide NICU device-associated rates stratified by birth-weight group. Denominators used to calculate device-associated infection rates also varied, with hospitals reporting either patient-days or device-days. These findings suggest the need to determine reasons for variations and to identify optimal NI surveillance methods at children's hospitals so that valid interhospital NI rate comparisons can be made.

Critical evaluation of a CLIA-waived streptococcal antigen detection test in the emergency department

STUDY OBJECTIVE

We compare the performance of a Clinical Laboratory Improvement Amendments (CLIA)-waived antigen detection test (ADT) analyzed in the emergency department and a CLIA moderately complex ADT performed in the hospital microbiology laboratory.

METHODS

Samples from throat swabs were obtained using a double-headed Culturette II (Becton Dickinson Medical Systems, Sparks, MD) from a consecutive sample of 322 patients 3 years or older who presented to the ED of a university-affiliated pediatric referral hospital with the complaint of sore throat during 1998. One swab was transported to the microbiology laboratory and analyzed using a CLIA moderately complex ADT; negative results were confirmed using sheep blood agar culture. The second swab remained in the ED where a nurse conducted a CLIA-waived ADT. The accepted standard for documentation of group A beta-hemolytic streptococcal (GABHS) infection was either a positive moderately complex ADT or culture result. The time of specimen collection, as well as the time the ED results and microbiology laboratory results were available to treating physicians, were recorded. Main outcome measures were concordance (kappa statistic), sensitivity, and turnaround time (Mann-Whitney U test).

RESULTS

Three hundred twenty-two patients (mean age 7.5 years) had both ADTs performed. One hundred one (31%) patients had documented GABHS in the microbiology laboratory; 83 (82%) had a positive ADT result in the microbiology laboratory, and 18 (18%) had a positive culture result after a negative moderately complex ADT result. In 299 patients or 93% (95% confidence interval [CI] 90.8%, 95.8%) of patients, the waived ADT and the moderately complex ADT results were concordant (kappa 0.82; 95% CI 0.78, 0.86; P <.001). The sensitivity of the waived ADT was 80%; the sensitivity of the moderately complex ADT approximated 82% (difference of 2%; 95%CI -3%, 7%). The median times from swab specimen collection to availability of ADT results were 10 minutes (range 3 to 37 minutes) for the waived ADT and 35 minutes (range 5 to 162 minutes) for the moderately complex ADT (P <.001) with a difference of 25 minutes (95% CI 22.4, 27.6 minutes).

CONCLUSION

In this study, an ED CLIA-waived rapid streptococcal throat test performed as well as its equivalent CLIA-regulated laboratory test. Further, the ED test provided results more rapidly than the laboratory test. Our results also validate previous work that negative rapid throat test results in pediatric patients in the ED should be confirmed by standard throat culture.

Severe neonatal enteroviral hepatitis treated with pleconaril

Neonatal enteroviral hepatitis carries high morbidity and mortality. We treated three full term neonates with severe enteroviral hepatitis with pleconaril on an open label compassionate use protocol. Each mother had history of a viral-like syndrome within 1 week before delivery. The neonates presented at 4 to 5 days of age with fulminant hepatic failure with severe coagulopathy, and each yielded an echovirus. All were treated with pleconaril (VP63843) at 5 mg/kg every 8 h by nasogastric tube. Two of the three neonates with life-threatening enteroviral hepatitis recovered fully. Further experience with pleconaril for neonatal enteroviral hepatitis is warranted.

Circulating cardiac troponin I levels in Kawasaki disease

In addition to the vascular findings of Kawasaki disease (KD), clinical, electrocardiographic, and/or echocardiographic signs of myocarditis are recognizable in the acute phase of KD in many patients. The mechanism of myocarditis and an association with the development of subsequent coronary artery abnormalities in KD is unknown. Previous studies of serum cardiac troponin I (cTnI) measurements in pediatric populations have suggested a possible utility of measurements in diagnosis and follow-up of KD. We designed a retrospective study to evaluate cTnI measurements during acute KD and to assess the predictive value of cTnI measurements in acute KD for the subsequent development of coronary artery abnormalities. Twenty-nine children were studied. Group 1 consisted of 15 KD patients who developed coronary artery abnormalities as detected by transthoracic echocardiographic evaluation. Group 2 consisted of 14 KD patients with persistently normal coronary artery findings on echocardiograms. A control group consisted of 11 children, none of whom were known to have had clinical findings of KD or myocarditis. The mean cTnI values for all three groups were lower than the values suggestive of cardiac damage: group 1 = 0.11 +/- 0.16 ng/ml, group 2 = 0.15 +/- 0.34 ng/ml, and control = 0.04 +/- 0.08 ng/ml. The current study demonstrates that there is no significant elevation of cTnI in KD patients. Additionally, there is no correlation between cTnI measurements and the finding of myocarditis, as reflected by decreased cardiac function, or the subsequent development of coronary artery abnormalities.

Oligoclonal IgA response in the vascular wall in acute Kawasaki disease

Kawasaki Disease (KD) is a potentially fatal acute vasculitis of childhood. Although KD is the leading cause of acquired heart disease in children in developed nations, its pathogenesis remains unknown. We previously reported the novel observation that IgA plasma cells infiltrate the vascular wall in acute KD. We have now examined the clonality of this IgA response in vascular tissue from three fatal cases of KD to determine whether it is oligoclonal, suggesting an Ag-driven process, or polyclonal, suggesting nonspecific B cell activation or a response to a superantigen. We first sequenced VDJ junctions of 44 alpha genes isolated from a primary, unamplified KD vascular cDNA library. Five sets of clonally related alpha sequences were identified, comprising 34% (15 of 44) of the isolated alpha sequences. Furthermore, point mutations consistent with somatic mutation were detected in the related sequences. Next, using formalin-fixed coronary arteries from two additional fatal KD cases, we sequenced VDJ junctions of alpha genes isolated by RT-PCR, and a restricted pattern of CDR3 usage was observed in both. We conclude that the vascular IgA response in acute KD is oligoclonal. The identification of an oligoclonal IgA response in KD strongly suggests that the immune response to this important childhood illness is Ag-driven.

Myocardial injury in children with respiratory syncytial virus infection

OBJECTIVE

Respiratory syncytial virus (RSV) infection is associated with a number of extrapulmonary manifestations, including a sepsis-like syndrome characterized by any combination of hypothermia, fever, apnea, hypovolemia, and myocardial dysfunction. We hypothesized that RSV can have a direct injurious effect on the myocardium of infants and children that can be detected by the presence of cardiac troponin I (cTnI), a highly sensitive and specific marker of myocardial injury, in the blood of patients infected with the virus.

DESIGN

Serial cTnI measurements were obtained from patients admitted with documented RSV infection to the pediatric intensive care unit (PICU).

PARTICIPANTS

Data were collected and analyzed from 22 RSV infected patients and 11 control patients.

RESULTS

Elevated levels of cTnI were detected in 54.5% (12/22) of the study population during their PICU admission. The average cTnI level was significantly higher in the RSV infected group than in controls. There was a significant association between the presence of a positive troponin assay and the occurrence of a cardiovascular event, the need for inotropic support, and the requirement of mechanical ventilation. Patients who required inotropic support had a significantly higher cTnI level than the rest of the study population.

CONCLUSION

A large percentage of children admitted to the PICU with RSV infection have myocardial damage as detected by the use of commercially available troponin assays. Additionally, in a portion of these patients, this damage is clinically significant, leading to cardiovascular instability and the need for inotropic support.

IgA plasma cell infiltration of proximal respiratory tract, pancreas, kidney, and coronary artery in acute Kawasaki disease

The etiology and pathogenesis of Kawasaki disease (KD) remain unknown. As previously reported, in US patients with acute KD, IgA plasma cells (PCs) infiltrate the vascular wall. To determine whether IgA PCs are increased at mucosal sites in KD and to determine whether other nonvascular KD tissues are infiltrated by IgA PCs, the cells were immunolocalized and quantitated in tissue sections taken from 18 US and Japanese patients who died of acute KD and from 10 age-matched controls. IgA PCs were significantly increased in the trachea of patients who died of acute KD, compared with controls (P<.01), a finding that was similar to findings in children with fatal respiratory viral infection. IgA PCs also infiltrated coronary artery, pancreas, and kidney in all KD patients. These findings strongly support entry of the KD etiologic agent through the upper respiratory tract, resulting in an IgA immune response, with systemic spread to vascular tissue, pancreas, and kidney.

Kawasaki disease in older children and adolescents

Features of 28 patients older than 8 years of age with acute Kawasaki disease were reviewed. Observations included a predominance of male patients and white patients, delays in diagnosis of acute Kawasaki disease, presence of additional signs and symptoms, and a substantial incidence of coronary artery abnormalities (21%) including mild transient changes.

New perspectives in the drug treatment of Kawasaki disease

Kawasaki disease (KD) has become the leading cause of acquired heart disease in developed countries. Conventional therapy for KD includes intravenous gammaglobulin (2 g/kg as a single dose over 12 hours) and aspirin (acetylsalicylic acid; high dose until the fourteenth day of illness then low dose). Therapy administered within the first 10 days of the onset of the illness has been shown to reduce arterial wall inflammation and thereby prevent the development of coronary artery aneurysm formation. The majority of patients with KD will respond to conventional therapy. However, the management of nonresponders and patients with complications (such as acute thrombosis and chronic coronary artery changes) remains controversial. In this review article, we address some of these controversies and also describe newer treatment modalities that have been used in the management of patients with KD, both in the acute and convalescent stages of the disease.

Potential mechanisms for failure to eradicate group A streptococci from the pharynx

OBJECTIVE

To investigate the relative efficacy of orally administered cefadroxil and penicillin V in the treatment of group A streptococcal (GABHS) pharyngitis and the mechanism(s) responsible for failure of antimicrobial therapy to eradicate GABHS from the pharynx.

STUDY DESIGN

A prospective, randomized clinical trial was conducted in four pediatric offices in which 462 patients with acute pharyngitis and positive culture for GABHS were randomly assigned to receive cefadroxil (n = 232) or penicillin V (n = 230).

RESULTS

Bacteriologic treatment success rates for patients in cefadroxil and penicillin groups were 94% and 86%, respectively. However, among patients classified clinically as likely to have bona fide GABHS pharyngitis, there was no difference in bacteriologic treatment success rates in cefadroxil and penicillin groups (95% and 94%, respectively). Among patients classified clinically as likely to be streptococcal carriers, bacteriologic treatment success rates in cefadroxil and penicillin groups were 92% and 73%, respectively. The presence of beta-lactamase and/or bacteriocin-producing pharyngeal flora had no consistent effect on bacteriologic eradication rates among patients in either penicillin or cefadroxil treatment groups or among patients classified as having either GABHS pharyngitis or streptococcal carriage.

CONCLUSIONS

Neither beta-lactamase nor bacteriocin produced by normal pharyngeal flora are related to bacteriologic treatment failures in GABHS pharyngitis. Cefadroxil seems to be more effective than penicillin V in eradicating GABHS from patients classified as more likely to be streptococcal carriers. However, among patients we classified as more likely to have bona fide GABHS pharyngitis, the effectiveness of cefadroxil and penicillin V seems to be comparable.

Multiple recurrent gram-negative cerebrospinal fluid shunt infections associated with a patient with a retained ventricular foreign body

A 3-year-old boy experienced 10 recurrent gram-negative ventriculoperitoneal shunt (VPS) infections with identical strains over a 17-month period. Multiple cranial MRI and CT scans to identify a retained foreign body were negative. CT myelography and pressure infusion radionuclide cisternography were also unhelpful. Ventriculoscopy revealed a small retained foreign body which was successfully removed, and cultures subsequently yielded gram-negative organisms identical to the previously identified bacteria by pulsed field gel electrophoresis. No further infections were noted after removal of the retained fragment. Exploratory ventriculostomy should be considered in patients with recurrent VPS infections where other techniques fail to reveal a cause.

Kawasaki disease

Kawasaki disease is a leading cause of acquired heart disease among children in the United States and other developed countries. Most children who contract this illness are less than two years old, and 80 percent of affected children are younger than five years of age. A generalized vasculitis of unknown etiology, Kawasaki disease can cause coronary artery abnormalities, including coronary aneurysms. From 20 to 25 percent of untreated children develop coronary artery abnormalities, which may resolve or persist. These abnormalities are of particular concern because they can lead to thrombosis, evolve into segmental stenosis or, rarely, rupture. The principal cause of death from Kawasaki disease is myocardial infarction. The cause of the disease remains unknown, but epidemiologic investigations and the clinical presentation suggest a microbial agent. Diagnostic criteria, including fever and other principal features, have been established. In the acute phase of the disease, treatment with acetylsalicylic acid and intravenously administered immunoglobulin is directed at reducing inflammation of the coronary arteries and myocardium. Early recognition and treatment of Kawasaki disease can reduce the development of potentially life-threatening coronary artery abnormalities.

Kawasaki syndrome

Kawasaki syndrome is a fascinating worldwide illness of young children. This acute self-limited vasculitis has become the most common cause of acquired heart disease in children in the United States and Japan. KS causes significant coronary artery disease that may lead to myocardial infarction and sudden death. Clinical and epidemiologic features of KS support an infectious cause, but the etiology remains unknown. Clearly, additional research on the cause of KS and its pathogenesis is needed urgently to allow for improved diagnosis; more specific therapy; and, ultimately, prevention of the disorder.

Report of the National Institutes of Health Workshop on Kawasaki Disease

The National Institute of Allergy and Infectious Disease, National Institutes of Health convened a workshop on Kawasaki disease, May 1997, co-chaired by Drs. Karyl Barron and Stanford Shulman. The goal of the workshop was to review the latest scientific advances relating to the epidemiology, etiology, pathogenesis, treatment, and complications of Kawasaki disease, along with future therapeutic options and proposed future research directions.

Are the Duke criteria superior to the Beth Israel criteria for the diagnosis of infective endocarditis in children?

Accurate diagnosis of infective endocarditis may be difficult. The Beth Israel criteria and the newer Duke criteria assign probability to the diagnosis of infective endocarditis on the basis of the presence of common features and manifestations. We reviewed 111 cases of pediatric infective endocarditis diagnosed and treated over 19 years. Each case was classified by the two criteria, and the results were compared. Of 111 cases, 73 (66%) and 18 (16%) were classified as definite by the Duke criteria and the Beth Israel criteria, respectively. No cases were rejected by the Duke criteria, while 21 (19%) of 111 were rejected by the Beth Israel criteria. In 18 pathologically proven cases, reanalysis without pathological data showed that the Duke criteria had significantly greater sensitivity (83%) than the Beth Israel criteria (67%) (P < .03). Echocardiographic evidence was required in 22 cases for definite classification by the Duke criteria; none were rejected, however, when echocardiographic findings were ignored. Our results suggest that the Duke criteria are superior to the Beth Israel criteria for the diagnosis of pediatric infective endocarditis.

Kawasaki syndrome

Kawasaki syndrome (KS) is an acute, sometimes fatal vasculitis of young children. KS has replaced acute rheumatic fever as the most common cause of acquired heart disease in children in the United States. The illness is manifested by prolonged fever, conjunctival injection, enanthem, exanthem, erythema and swelling of the hands and feet, and cervical adenopathy. These acute features of illness are self-limiting, but coronary artery abnormalities occur in 20% of untreated patients. The etiology of the illness is unknown, but its clinical and epidemiologic features are most consistent with an infectious cause. Common cardiovascular manifestations of the illness include myocarditis, pericardial effusion, and coronary artery aneurysm formation. Treatment with intravenous gamma globulin (IVGG) and aspirin within the first 10 days of illness reduces the prevalence of coronary artery abnormalities from 20% in those treated with aspirin alone to 4%. Patients who develop coronary artery aneurysms, particularly those who develop giant coronary artery aneurysms, may suffer myocardial infarction secondary to thrombosis or stenosis in the abnormal vessel. Additional research to determine the cause of KS is urgently needed to allow for improved diagnosis, more specific therapy, and prevention of the disorder.

IgA plasma cells in vascular tissue of patients with Kawasaki syndrome

The etiology and pathogenesis of Kawasaki syndrome (KS) remain unknown. Clinical and epidemiologic features of KS are consistent with an infectious cause. To search for an etiologic agent of KS, a phage cDNA expression library was constructed from the aorto-iliac junction of a patient with fatal acute KS and screened with convalescent KS serum followed by anti-human Ig. Unexpectedly, 0.1% of the clones in the library react with anti-human Ig, indicating the presence of many Ig-producing B lymphocytes in the vasculitic tissue. To confirm this finding and to determine the isotypes produced, frozen vascular tissue sections from the patient and paraffin sections from coronary arteries from six additional patients with fatal acute or subacute KS were incubated with Abs to Ig isotypes. Histopathology of the tissues revealed the presence of many plasma cells in the inflammatory infiltrate. IgA was the predominant isotype produced in vascular tissue in all seven KS patients. IgM- and IgG-producing cells were less often detected. We conclude that there is a marked plasma cell response within the vasculitic tissue in KS, with unusual IgA production locally in this nonlymphoid, nonmucosal tissue. We suggest that the prominence of IgA plasma cells in the vascular infiltrate in the early, acute, and subacute stages of KS indicates an Ag-driven immune response to an etiologic agent with a respiratory or gastrointestinal portal of entry and speculate that this unusual immune response is integral to the pathogenesis of the illness.

IgA plasma cells in vascular tissue of patients with Kawasaki syndrome

The etiology and pathogenesis of Kawasaki syndrome (KS) remain unknown. Clinical and epidemiologic features of KS are consistent with an infectious cause. To search for an etiologic agent of KS, a phage cDNA expression library was constructed from the aorto-iliac junction of a patient with fatal acute KS and screened with convalescent KS serum followed by anti-human Ig. Unexpectedly, 0.1% of the clones in the library react with anti-human Ig, indicating the presence of many Ig-producing B lymphocytes in the vasculitic tissue. To confirm this finding and to determine the isotypes produced, frozen vascular tissue sections from the patient and paraffin sections from coronary arteries from six additional patients with fatal acute or subacute KS were incubated with Abs to Ig isotypes. Histopathology of the tissues revealed the presence of many plasma cells in the inflammatory infiltrate. IgA was the predominant isotype produced in vascular tissue in all seven KS patients. IgM- and IgG-producing cells were less often detected. We conclude that there is a marked plasma cell response within the vasculitic tissue in KS, with unusual IgA production locally in this nonlymphoid, nonmucosal tissue. We suggest that the prominence of IgA plasma cells in the vascular infiltrate in the early, acute, and subacute stages of KS indicates an Ag-driven immune response to an etiologic agent with a respiratory or gastrointestinal portal of entry and speculate that this unusual immune response is integral to the pathogenesis of the illness.

Prevention of bacterial endocarditis: recommendations by the American Heart Association

OBJECTIVE

To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease.

PARTICIPANTS

An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy.

EVIDENCE

The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence.

CONSENSUS PROCESS

The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment.

CONCLUSIONS

Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Prevalence of coronary artery abnormalities in Kawasaki disease is highly dependent on gamma globulin dose but independent of salicylate dose

The efficacy of intravenous gamma globulin (IVGG) for treatment of Kawasaki disease (KD) is clearly established. In a metaanalysis, we reviewed U.S. and Japanese multicenter, randomized controlled studies regarding the effect of various doses of IVGG with aspirin administered within the first 7 to 10 days of illness on the prevalence of coronary artery abnormalities in KD. We studied 1629 patients with acute KD from the six reported studies that included blinded echocardiographic assessments. In 868 Japanese patients treated with moderate-dose aspirin (30 to 50 mg/kg per day), the prevalence of coronary abnormalities at the subacute stage (illness day 30) was 26.8% with aspirin alone, 18.1% with total IVGG dose < 1 gm/kg, 17.3% with total IVGG of 1.0 to 1.2 g/kg, and 5.3% with total IVGG of 2 gm/kg; the corresponding prevalence at the convalescent stage of illness (illness day 60) was 17.5%, 13.5%, 9.8%, and 3.5%, respectively. In 761 U.S. patients treated with high-dose aspirin (80 to 120 mg/kg per day), the prevalence of coronary abnormalities at the subacute stage (2 to 3 weeks after enrollment) was 23.0% with aspirin alone, 9.0% with total IVGG of 1.0 gm/kg, 8.6% with total IVGG of 1.6 gm/kg, and 4.6% with total IVGG of 2.0 gm/kg; corresponding prevalence at the convalescent stage (6 to 8 weeks after enrollment) was 17.7%, 9.0%, 6.3%, and 3.8%, respectively. When all data for the 1629 patients were combined, the prevalence at the subacute stage was 25.8% with aspirin alone, 18.1% with IVGG < 1 gm/kg, 15.7% with IVGG of 1 to 1.2 gm/kg, 8.6% with IVGG of 1.6 gm/kg, and 4.8% with IVGG of 2 gm/kg (adjusted R2 = 0.966, p = 0.0017); corresponding prevalence at the convalescent stage was 17.6%, 13.5%, 9.7%, 6.3%, and 3.8%, respectively (adjusted R2 = 0.993, p = 0.0602). The prevalence of coronary abnormalities was inversely related to the total dose of IVGG and was independent of the aspirin dose. We conclude that 2 gm/kg IVGG combined with at least 30 to 50 mg/kg per day aspirin provides maximum protection against development of coronary abnormalities after KD.

Serum amyloid A and high density lipoprotein participate in the acute phase response of Kawasaki disease

In this study we report changes in HDL concentration and composition in acute and convalescent Kawasaki disease. Notable reductions in plasma HDL-cholesterol (0.54 +/- 0.2 mmol/L, normal level 0.7-1.81 mmol/L) and apolipoprotein A-I (apoA-I) (56 +/- 28 mg/dL, normal level 141 +/- 22 mg/dL) were observed in all 24 patients studied during the acute phase of Kawasaki disease. These changes were accompanied by the marked appearance of serum amyloid A (SAA) protein in the plasma, associated with HDL3-like lipoprotein particles. The distribution of apoA-I was analyzed in five patients and showed a significant increase in lipid-free apoA-I in the bottom fraction (28.8 +/- 4.1%, normal range 10-15%), suggesting displacement of apoA-I from the HDL particles by SAA. Within 2 wk after acute Kawasaki disease, levels of HDL-cholesterol and apoA-I returned to the normal range, and SAA disappeared from the plasma. The HDL of patients with Kawasaki disease was markedly enriched in triglyceride even in the absence of changes in total plasma triglyceride. The core composition of HDL returned to the normal range more slowly than the plasma HDL-cholesterol and apoA-I levels. This suggests that Kawasaki disease has a profound effect on the lipoprotein profile acutely and a more subtle sustained effect on the HDL composition. We interpret these changes as manifestations of the acute phase response in Kawasaki disease.

Cardiac transplantation for Kawasaki disease

OBJECTIVE

Severe cardiac sequelae from Kawasaki disease include coronary ischemia and have been treated with a variety of coronary artery bypass procedures. There is only one published report of a child who underwent cardiac transplantation for severe Kawasaki disease-related cardiac complications. The purpose of this study was to gather the worldwide experience with cardiac transplantation for Kawasaki disease.

METHODS

Data were obtained from the United Network for Organ Sharing Registry, the European transplant experience, and a phone survey of many Kawasaki disease investigators. Diagnostic and surgical reports as well as clinical records were reviewed. Results. We identified 13 Kawasaki disease patients who underwent cardiac transplantation and obtained data on 10. In these 10 patients, the timing of transplantation was within 6 months after diagnosis of Kawasaki disease (4 patients), 1 to 5 years after diagnosis (3 patients), and 9 to 12 years after diagnosis (3 patients). Indications for transplantation included severe myocardial dysfunction, severe ventricular arrhythmias including cardiac arrest, and severe distal multivessel occlusive coronary artery disease. Nine of the 10 patients remain alive and healthy, with up to 6 years' posttransplant follow-up. One patient died 10 months posttransplant after severe refractory rejection. In addition, 1 patient required retransplantation at 4 years for severe rejection.

CONCLUSIONS

Cardiac transplantation for severe ischemic heart disease as a sequela of Kawasaki disease is feasible and can benefit the small subgroup of patients who are not candidates for revascularization because of distal coronary stenosis or aneurysms and/or those with severe irreversible myocardial dysfunction.

Prevention of bacterial endocarditis: recommendations by the American Heart Association

OBJECTIVE

To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease.

PARTICIPANTS

An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the infectious Diseases Society of America, the American Academy of Pediatrics and the American Society for Gastrointestinal Endoscopy.

EVIDENCE

The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using root words endocarditis, bacteremia and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the U.S. Preventive Services Task Force categories of evidence.

CONSENSUS PROCESS

The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment.

CONCLUSIONS

Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate- and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered.

Prevention of bacterial endocarditis. Recommendations by the American Heart Association

OBJECTIVE

To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease.

PARTICIPANTS

An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy.

EVIDENCE

The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence.

CONSENSUS PROCESS

The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment.

CONCLUSIONS

Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Prevention of bacterial endocarditis. Recommendations by the American Heart Association

OBJECTIVE

To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease.

PARTICIPANTS

An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy.

EVIDENCE

The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence.

CONSENSUS PROCESS

The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment.

CONCLUSIONS

Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Optical immunoassay test for group A beta-hemolytic streptococcal pharyngitis. An office-based, multicenter investigation

OBJECTIVE

To compare the accuracy of an optical immunoassay (OIA) for the rapid diagnosis of group A streptococcal pharyngitis with blood agar plate (BAP) culture.

DESIGN

Blinded comparison with criterion standard.

SETTING

A total of 6 private pediatricians' offices, 3 in Connecticut and 3 in Chicago, III.

PATIENTS

A total of 2113 consecutive patients with acute pharyngitis, 983 in Connecticut and 1130 in Chicago.

MAIN OUTCOME MEASURES

The sensitivities and specificities of OIA and BAP culture (both performed and interpreted in the office) were determined using a research laboratory's interpretation of a combination of BAP culture and Todd-Hewitt broth (THB) culture of transport tube pledget as criterion standard.

RESULTS

Among patients in Connecticut, the sensitivities of the OIA and BAP culture were 94% and 89%, respectively (P=.004), while the specificities were 96% and 99%, respectively (P=.001). Among patients in Chicago, the sensitivities of the OIA and BAP culture were 79% and 72%, respectively (P<.001), while the specificities were 89% and 99%, respectively (P<.001). In each of the 6 pediatricians' offices, the OIA was more sensitive than the BAP culture. Combining the data from Connecticut and Chicago, the overall sensitivities of the OIA and BAP culture were 84% and 78%, respectively (P<.001), while the specificities were 93% and 99%, respectively (P<.001).

CONCLUSIONS

The results of this comprehensive office-based investigation suggest that with adequately trained personnel, negative OIA test results may not always need to be routinely confirmed with BAP cultures.