Use of ELISA to measure antinuclear antibodies in children with juvenile rheumatoid arthritis

OBJECTIVE

To compare a series of commercial ELISA tests with an indirect immunofluorescent antibody (IFA) test for the detection of antinuclear antibodies (ANA) in children with juvenile rheumatoid arthritis (JRA).

METHODS

Sera from 178 patients with JRA (88 pauciarticular, 68 polyarticular, 22 systemic) were compared with 26 healthy pediatric subjects. Twenty-one samples from patients with systemic lupus erythematosus (SLE) were also tested. All samples were analyzed by IFA and by 3 commercial ELISA methods. Concordance of ELISA results with IFA results (selected standard) were used as a measure of performance. Sensitivity and specificity were calculated for each test and likelihood ratios (LR) were established for IFA and ELISA in pauciarticular and polyarticular JRA sera. The increment in pretest probability was then obtained for each test as an additional measure of test performance.

RESULTS

IFA rendered positive results on 18-77% of the JRA sera depending upon the subset, 100% of SLE sera, and 15% of normal patient sera. Using IFA as the standard, correspondence with positive results among patients with JRA ranged from 0 to 74% for the 3 ELISA tests, while it ranged from 5 to 73% in IFA negative sera. IFA tests showed intermediate range likelihood ratios (0.3, 0.5, 3.5, and 5) and increments in pretest probability ranging from 25 to 45%. While one of the ELISA tests attained 50% of increment in pretest probability for the positive test, it showed 0% increment as a negative test. The other 2 ELISA tests incremented the pretest probability from 0 to 25%.

CONCLUSION

Our findings indicate that in JRA, the lack of correspondence with the historic standard IFA precludes the use of ELISA tests for detection of ANA. In addition, IFA out-performs ELISA by a substantial degree when "clinical utility" analysis of test performance is utilized. Detection of ANA in children with JRA should either continue to rely on IFA or be based on a different set of antigens if an ELISA format is chosen.

Comparison of immunodot and western blot assays for diagnosing Lyme borreliosis

Two commercially available serologic tests for use in diagnosing Lyme borreliosis were evaluated by using a test panel comprised of sera from patients diagnosed with Lyme borreliosis, non-Lyme disease controls, and healthy subjects. The test methods examined were a Western blot assay and an immunodot assay. The study was initiated to determine how the immunodot assay, which contains purified and recombinant proteins to those borrelial antigens recommended for immunoglobulin M (IgM) detection in the Dearborn criteria, would compare with the Western blot assay as a confirmatory method for serologic diagnosis of Lyme borreliosis. Results obtained showed that the two test methods performed comparably for detecting IgG antibodies. For IgM antibody detection, the immunodot and Western blot assays had similar sensitivities; however, the immunodot assay was more specific and had greater positive predictive value than the Western blot assay. The results obtained indicate that the immunodot assay performs as well as or better than the Western blot assay for diagnosing Lyme borreliosis. Furthermore, because it uses a limited panel (n = 5) of antigens, the immunodot is easier to read and interpret than standard Western blots.

Correlation of seroreactivity with response to antibiotics in pediatric Lyme borreliosis

Response to treatment with antibiotics was compared with serologic reactivity and clinical symptoms in a pediatric population with presumptive diagnoses of Lyme borreliosis. The population analyzed for this study consisted of a subset of a larger Lyme clinic population being monitored as part of a prospective study on pediatric Lyme borreliosis. All patients resided in an area in which Ixodes scapularis and Borrelia burgdorferi are considered endemic. Serum from patients was tested by enzyme-linked immunosorbent assay and Western blotting. Response to antibiotics was evaluated by members of a pediatric Lyme clinic. Results showed that positive serologic test results correlate with a favorable response to antibiotics, as does the presence of erythema migrans (EM), regardless of serologic status. Seronegative patients without EM had chronic fatigue and arthralgia and/or myalgia as primary symptoms and did not respond to antibiotics, even when multiple courses of treatment were given. These results indicate that serologic tests designed to have high specificity can reliably rule out Lyme borreliosis in patients with chronic symptoms, thus preventing unnecessary treatment with antibiotics.

Residual serologic reactivity in children with resolved Lyme arthritis

OBJECTIVE

To define the pattern of persistent antibody response in children with resolved Lyme arthritis.

METHODS

From a cohort of 67 children with Lyme arthritis followed in our department since 1989, 19 were selected using these criteria: All patients (1) were asymptomatic; (2) had an ELISA titer < or = 1:160; (3) had been in treatment a minimum of 6 months. Their initial and late samples were assessed by Western blot and the pattern of reactivity was analyzed.

RESULTS

The mean interval between treatment and last sample was 9.6 months (6-23). Analysis of the last sample showed that only 5/19 were negative by ELISA and 4/19 were at the cutoff limit (1:80). Only 6 patients had fewer than 4 reactive bands, 4 had 4 bands, and 9 had 5-11 bands on Western blot. The 41, 39, and 60 kDa were the most commonly observed reactive bands at last evaluation. 31 and 34 kDa bands, while relatively common in initial samples (36%), became uncommon (5%) on late samples. A significant finding was the absence of IgM reactivity in 18/19: 1/19 had 41 kDa reactivity. Only 4 patients had both ELISA (< 1:80) and Western blot tests negative (< 5 reactive bands).

CONCLUSION

All patients with resolved Lyme arthritis continue to show serologic reactivity beyond 6 months of therapy. 68% of the patients satisfy Western blot criteria for positivity in our laboratory. IgM reactivity to any antigen was minimal and IgG reactivity against the 41 kDa antigen, considered diagnostic of infection in initial samples by some laboratories, is very common (16/19).

The overdiagnosis of Lyme disease in children residing in an endemic area

The medical records of 227 children ages 1 to 19 years referred to the Lyme disease pediatric clinic over a 32-month period since May 1990 were reviewed. Clinico-serologic criteria for a positive diagnosis were applied. One hundred thirty-eight of 227 referred children did not fulfill those criteria and became the study population. Four subsets of patients emerged: (1) 54 patients with predominantly subjective symptoms; (2) 52 patients with objective evidence for an alternative diagnosis; (3) eight patients who had documented infection in the past and continued with symptoms after antibiotic treatment; and (4) 24 patients with a history of tick attachment or prenatal/family history of Lyme disease. Serologic testing data from commercial laboratories were available for the 54 children from the "predominantly subjective" group; 50% were negative, and 50% were borderline or positive. Ninety-two percent of these patients were negative at retesting by our enzyme-linked immunosorbent assay (ELISA) and 100% were negative by Western blot. Fifty-seven percent of these patients had received treatment prior to our evaluation. Children residing in an endemic area who present with vague symptoms are being diagnosed with and treated for Lyme disease without clinical or serologic documentation. In addition, fear in the lay community may be inducing doctors to diagnose Lyme disease in patients with symptoms that may be suggestive of an alternative diagnosis.

Serial measurements of soluble interleukin 2 receptor levels (sIL2-R) in children with juvenile rheumatoid arthritis treated with oral methotrexate

OBJECTIVE

To investigate the potential clinical utility of serial levels of sIL2-R as a marker of disease activity among children with juvenile rheumatoid arthritis (JRA) treated with methotrexate (MTX).

METHODS

sIL2-R levels, measured by ELISA, were evaluated in 16 JRA patients (10 polyarticular, six systemic-onset) treated with oral, weekly MTX. sIL2-R values were compared with those of 49 normal controls. Medical record review was used to obtain relevant clinical data. Joint counts (number of swollen joints) were used as indicators of clinical change. A reduction of 50% in joint counts between pre and post treatment measurements was considered a clinically significant response.

RESULTS

The mean (SEM) sIL2-R value of pre treatment JRA of 1728(290) U/ml was significantly higher than the post treatment value of 921(229) U/ml (Wilcoxon Rank test, p < or = 0.001). Pre treatment values were also significantly different from the mean(SEM) of healthy controls of 519(19) U/ml (p < 0.001). Pre treatment sIL2-R levels of 2417(291) U/ml in systemic-onset JRA were significantly higher than sIL2-R values in polyarticular JRA patients of 1218(884) U/ml (Mann-Whitney rank test p < 0.001). Among the 13/16 children with good therapeutic responses (> or = 50% improved), the range of sIL2-R decreases was 154-2641 U/ml (mean 842 U/ml); sIL2-R levels increased in the three children with poor clinical responses to methotrexate.

CONCLUSIONS

sIL2-R levels paralleled the course of disease in all patients. sIL2-R levels may be useful for monitoring therapeutic responses in children with JRA.

Pediatric Lyme arthritis: clinical spectrum and outcome

A cohort of children with Lyme arthritis was used to evaluate the clinical and serologic profile of the disease. During a 42-month period (June 1989 to December 1991), 44 patients (13 girls and 31 boys, ages 4-18 years) were included and followed for 6-36 months. Inclusion required the presence of arthritis, as well as positive serology. Thirty-four children with juvenile rheumatoid arthritis or spondyloarthropathy were used as a serologic comparison group. Five different patterns of arthritis were found. Preceding erythema migrans was seen in seven children. Antinuclear antibodies were positive in 30% of the patients. Three treatments were used and selected according to physician preference, patient age, and presence of extraarticular disease: amoxicillin, doxycycline, and ceftriaxone. Articular disease reached complete resolution in all patients within 2-12 weeks. Lyme arthritis in children may mimic other pediatric arthritides. Prognosis for children with clearly defined Lyme arthritis was excellent.

Reinfection in paediatric Lyme borreliosis

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Serial measurement of soluble interleukin 2 receptor levels: an early indicator of treatment response for Lyme disease

Detection of antibodies produced in response to infection with Borrelia burgdorferi provides a valuable aid for diagnosing Lyme disease. However, anti-Borrelial antibody titers are of little value in determining treatment success or providing evidence of persistent infection as levels of specific antibodies can remain elevated even after successful treatment. Pretreatment and posttreatment measurement of soluble interleukin 2 receptor (sIL-2R) levels was evaluated for use in predicting treatment response in Lyme disease. Results indicate that serial measurement of serum sIL-2R levels can provide an early indicator of response to treatment and outcome.

Detection of antibodies to the recombinant P39 protein of Borrelia burgdorferi using enzyme immunoassay and immunoblotting

The diagnostic value of serologic tests using the recombinant P39 protein of Borrelia burgdorferi was compared with that of tests prepared from a whole spirochete antigen source. Immunoassays (ELISA and Western blot) prepared from either the recombinant protein or whole spirochetes were evaluated using a test panel comprised of 2 sera groups, one obtained from patients with clinically diagnosed Lyme disease, the other from individuals with no indication of past or current infection with B. burgdorferi. Results obtained indicate that ELISA screening tests relying on the recombinant protein are less sensitive than ELISA tests using whole spirochete antigen preparations. Western blot tests based on the P39 protein were more specific than P39 ELISA yielding no false positive or indeterminate results. These findings suggest that the P39 protein may prove valuable for confirmation testing for Lyme disease.

Pharmacological management of juvenile rheumatoid arthritis

The goals of pharmacotherapy in juvenile rheumatoid arthritis (JRA) are to suppress chronic synovitis which causes potential cartilage destruction and deformities, to control the systemic effects of inflammation (including growth retardation and nutritional deficits), relieve pain and limit psychological impact of disease. Currently available methods include nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, salicylates, naproxen, tolmetin, ibuprofen and indomethacin; disease modifying antirheumatic drugs (DMARDs) such as oral and injectable gold salts, hydroxychloroquine, penicillamine, oral and injectable methotrexate, and sulfasalazine; oral (daily or on alternate days), intravenous pulse or intra-articular corticosteroids; immunosuppresants, including cyclophosphamide, chlorambucil, cyclosporin, and azathioprine; and gammaglobulin and other experimental therapies. Over the past 10 years, rheumatologists have adopted more aggressive pharmacological treatment of JRA. As time progresses and the safety of certain drugs such as methotrexate and sulfasalazine becomes clearer, wider and earlier use of these agents can be expected. Still the approach to treatment is a 'step by step' one, starting with the classical NSAIDs and ending with the DMARDs as needed.

Frequency and specificity of antibodies that crossreact with Borrelia burgdorferi antigens

The frequency and specificity of antibodies that bind antigens of Borrelia burgdorferi in sera from 200 individuals with no evidence of past or current Lyme disease was determined. Sera were tested for both IgG and IgM antibodies to B. burgdorferi by Western blotting. The non-Lyme serum group included specimens from healthy adults and children in addition to specimens from patients with viral infection and rheumatic diseases. Crossreactive IgG antibodies occurred more frequently than IgM antibodies. The most frequently bound antigens corresponded to 41 kDa and 60 kDa Borrelial components. Of 200 specimens tested, 100 had antibodies that bound at least 1 antigen. Binding to multiple antigens occurred at much lower frequency. Our results indicate that determination of maximum crossreactivity of non-Lyme sera can be used to establish minimum criteria for determining a positive Western blot result for Lyme disease.

Use of western blot and enzyme-linked immunosorbent assays to assist in the diagnosis of Lyme disease

Without evidence of erythema chronicum migrans, diagnostic confirmation of Lyme disease may be difficult, particularly if there are conflicting laboratory results. Often, for families and physicians, the clinical dilemma is whether fatigue, arthritis/arthralgias, a positive enzyme-linked immunosorbent assay (ELISA), and tick exposure, but no evidence of erythema chronicum migrans, are sufficient to diagnose and treat Lyme disease. Patients with discordant ELISA and Western blot (WB) assay results for Borrelia burgdorferi were studied to determine whether there was sufficient clinical evidence to support a diagnosis of Lyme disease. Of 650 consecutive sera analyzed by ELISA in a laboratory within a 1-year period, 77 were subsequently tested by WB. The clinical data from these patients were then analyzed. The study population was divided into three groups: group 1 (positive ELISA, positive WB), group 2 (positive ELISA, negative WB), and group 3 (negative ELISA, negative WB). Findings included the following: (1) Patients with a strong clinical history of Lyme disease were usually positive by both WB and ELISA (group 1). (2) All patients with erythema chronicum migrans had both positive WB and ELISA tests. (3) Ninety-one percent of group 2 had a rheumatic or inflammatory condition other than Lyme disease. (4) A definite response to antibiotics occurred in 75% of patients wherein both ELISA and WB were positive but in only 11% of cases with a positive ELISA but a negative WB. (5) History of tick exposure and degree of fever were not significantly different among the three serologic groups, and thus they were not diagnostically helpful.(ABSTRACT TRUNCATED AT 250 WORDS)

Chief resident training. Developing leadership skills for future medical leaders

Most future medical leaders receive little or no formal exposure to management and leadership training activities. Industry invests considerable resources in such training for middle and senior level managers. With the increasing complexity of health care delivery systems and the increased involvement of diverse teams of individuals in the care of patients, it was believed that a training activity designed to enhance participant human interaction skills and teach about group behavior and team management might be valuable to pediatric chief residents. This article describes a 3-day workshop designed to develop such leadership skills. It has been conducted for 3 years with 117 participants. Results of end-of-course and 6-month follow-up evaluations show that participants enjoyed the training experience and believed it was valuable in helping them fulfill their leadership role as chief resident.

Adsorption with a soluble E. coli antigen fraction improves the specificity of ELISA tests for Lyme disease

We reported that preadsorption of patient serum with heat killed E. coli increased the specificity of ELISA for antibodies to Borrelia burgdorferi. That procedure required extra specimen handling and a preincubation. We report the use of a soluble E. coli antigen fraction that is included in serum diluent, eliminating additional steps. Sera from 220 individuals were tested for antibodies to B. burgdorferi. Twenty sera were obtained from patients with Lyme disease and 200 sera were from a population that included healthy controls and patients with different inflammatory conditions (viral infections and various rheumatic disorders). Testing was performed using either a standard serum diluent or one containing soluble E. coli antigen fraction. Results demonstrate that inclusion of soluble E. coli antigen fraction in serum diluent increased assay specificity from 88% for the standard protocol to 98%, with no change in test sensitivity.

The pediatric program director. An analysis of the role and its problems

A questionnaire designed to elicit information about the work environment, knowledge, and stresses of pediatric residency program directors was mailed to the 235 member programs of the Association of Pediatric Program Directors (APPD). At the time that the 187 respondents (80% return rate) assumed responsibility for their training programs, many rated their knowledge of various aspects of residency program administration as "poor." The respondents indicated that a lack of time, the pressures of too many other academic responsibilities, and a fear of not "filling" all positions in the National Intern Matching Program created much personal stress. Most program directors felt that educational conferences designed to teach educational methods, and administrative skills, and provide technical information knowledge necessary for residency program supervision would be beneficial.

Induction of humoral manifestations of autoimmunity following intraperitoneal injection of complete Freund's adjuvant in mice

Several animal models of arthritis are produced using complete Freund's adjuvant (CFA) alone or with collagen as an arthritogen. Successful induction of arthritis is reported to require that the adjuvant mixture be administered by intradermal or subcutaneous routes. The resulting arthritis is caused by primarily cellular immune responses. Data presented in this paper show that giving CFA by intraperitoneal (I.P.) inoculation results in a humoral autoimmune response, with no obvious signs of arthritis. This humoral autoimmune response is characterized by production of autoantibodies to nuclear and cytoplasmic antigens, elevated levels of circulating immune complexes, and in approximately 25% of mice, rheumatoid factor.

An adsorption procedure to increase the specificity of enzyme-linked immunosorbent assays for Lyme disease without decreasing sensitivity

Previous efforts to use adsorption techniques to enhance the specificity of enzyme-linked immunosorbent assays for antibodies to the spirochete that causes Lyme disease resulted in unacceptable reductions in assay sensitivity. We present here evidence that preadsorption of serum with Escherichia coli can enhance test specificity without significantly reducing test sensitivity.

Suppression of malaria-induced autoimmunity by immunization with cryoglobulins

Cryoglobulins obtained from malaria-infected (Plasmodium berghei berghei) Balb/c mice were administered intraperitoneally to naive Balb/c mice. Ten days or 9 months following cryoglobulin administration, the naive mice were infected with malaria. Comparison of sera from cryoglobulin-treated malaria-infected mice with sera from control infected mice revealed that pretreatment with cryoglobulins resulted in (1) reduced levels of circulating immune complexes; (2) reduced levels of autoantibodies reactive with nuclear and cytoplasmic antigens; and (3) suppressed development of cryoglobulinemia. Furthermore, the effect of cryoglobulins was long lasting, suggesting that recipient mice may have been actively immunized against autoantibody production.

Synovial fluid eosinophilia in Lyme disease

We describe three 14-year-old boys who developed synovial fluid eosinophilia associated with Lyme disease. One patient, with arthritis that began in 1975, had the first documented case of Lyme disease in New Jersey. Lyme disease should be considered when eosinophilia is noted on analysis of synovial fluid from patients with undiagnosed arthritis.

Esophageal motor abnormalities in children and adolescents with scleroderma and mixed connective tissue disease

To determine the frequency and nature of esophageal motor abnormalities in children and adolescents with scleroderma syndromes and mixed connective tissue disease, esophageal manometry was performed on seven patients with progressive systemic sclerosis, four patients with mixed connective tissue disease, and two patients with linear scleroderma. A total of 73% of patients with progressive systemic sclerosis and mixed connective tissue disease had symptoms of esophageal dysfunction. A significant association between the presence of Raynaud phenomenon and esophageal symptoms was noted. Esophageal motor abnormalities were detected in 73% of patients with progressive systemic sclerosis and mixed connective tissue disease; these abnormalities were characterized by decreased lower esophageal sphincter pressure and abnormal peristalsis in the distal two thirds of the esophageal body. They resemble those described among adults with progressive systemic sclerosis and mixed connective tissue disease but were not related to disease duration or to the presence of Raynaud phenomenon. Patients with linear scleroderma did not have esophageal symptoms and demonstrated only nonspecific motor abnormalities that did not worsen during several years of follow-up.

Childhood Lyme arthritis: experience in an endemic area

We report 25 children with oligoarticular arthritis associated with Lyme disease. There were 16 boys (male/female ratio 1.8:1); ages ranged from 2 to 15 years. Thirteen (52%) children had no history of erythema chronicum migrans or other rash. Thirteen had temperatures as high as 41 degrees C for up to 2 months before the onset of arthritis. Twelve recalled definite tick bites. Ten (40%) children, of whom seven had no history of rash, were hospitalized for presumed septic arthritis. Another four had diagnoses of pauciarticular juvenile rheumatoid arthritis for as long as 3 years. Seven patients had less acute, recurrent episodes of synovitis. Two children had seventh nerve palsies 2 months before onset of arthritis. All patients had antibodies to the Lyme spirochete. In 14 patients, synovial fluid white blood cell counts ranged from 180 to 97,700/mm3 (greater than or equal to 76% polymorphonuclear leukocytes). Antibiotic therapy was effective in all patients; in 13, orally administered therapy alone resulted in elimination of synovitis and recurrent attacks. Lyme arthritis may be confused with acute bacterial septic arthritis or recurrent "pauciarticular juvenile rheumatoid arthritis," particularly when there is no history of erythema chronicum migrans.

Utility of rheumatoid factor in the diagnosis of juvenile rheumatoid arthritis

Rheumatoid factor is commonly used by clinicians to assess children with possible juvenile rheumatoid arthritis. To assess its usefulness, we reviewed the case histories of patients in whom latex agglutinating rheumatoid factor was determined during 1981 to 1982 at our institution. A total of 437 charts were available for review. There were 11 patients with positive tests for rheumatoid factor, of whom five had juvenile rheumatoid arthritis, all polyarticular. A total of 426 children had negative results, of whom 100 had juvenile rheumatoid arthritis. This yields a sensitivity of 4.8% and a specificity of 98%. We then estimated the prevalence of juvenile rheumatoid arthritis in three clinical settings: a primary practitioner's office, a tertiary children's hospital walk-in clinic, and a pediatric rheumatology center. The predictive values and marginal benefits for rheumatoid factor were then calculated in those settings using Bayes' theorem. In the two general outpatient settings, the primary practitioner's office and tertiary walk-in clinic, the positive predictive values were 0.7% and 0.5%, respectively; marginal benefits were 0.4% and 0.3%, respectively. Rheumatoid factor testing appeared to be of some benefit in the pediatric rheumatology center with a positive predictive value of 72.5% and marginal benefit of 22.5%. In no case was rheumatoid factor testing helpful in establishing a diagnosis of juvenile rheumatoid arthritis or in ruling it out. Testing for rheumatoid factor is a poor screening procedure for juvenile rheumatoid arthritis in the general situations in which it is more likely to be requested and of supportive diagnostic value only in the highly restricted population of older children with polyarticular arthritis.

Arthropathy of Down's syndrome

Down's syndrome (trisomy 21) is associated with a variety of skeletal abnormalities and an increased incidence of joint hypermobility. Children with Down's syndrome are known to have a number of immunologic abnormalities and an increased incidence of autoimmune phenomena. We report 7 patients with Down's syndrome and arthritis. Four children had polyarticular disease and 3 had pauciarticular disease at onset. Only 1 child had significant cardiac disease. HLA typing in 5 children did not show specific correlations. Mean duration of followup was 3 years and 7 months. All children responded to nonsteroidal antiinflammatory drugs, but only 1 child is in clinical remission. Two children have died: 1 secondary to cervical spine instability and the other secondary to cardiac compromise. Arthropathy associated with Down's syndrome should be an additional exclusion for the diagnosis of juvenile rheumatoid arthritis. Further investigation of this association may give clues to the relationship between genetic and immunologic factors in the pathogenesis of joint inflammation.

Central nervous system involvement in childhood systemic lupus erythematosus

The records of 37 patients with systemic lupus erythematosus (SLE) followed at The Children's Hospital of Philadelphia between 1968 and 1978 were reviewed for evidence of central nervous system (CNS) involvement. Criteria for CNS involvement included evidence of organic brain syndrome, electroencephalographic abnormalities with symptoms referable to CNS, or objective neurologic signs. Sixteen of 37 children had CNS involvement (43%). Thirteen patients had CNS involvement at the onset of SLE. Three patients had late onset CNS manifestations 1 to 2 years after the diagnosis of SLE. The most frequently observed symptoms were headache, behavior disorder, lethargy, diplopia, blurred vision, memory alteration, dizziness, and alteration of consciousness. The most frequently observed neurologic signs were seizures, cranial nerve palsy, ataxia, papilledema, nystagmus, meningitis, tremor, rigidity, cortical blindness, and coma. Neuropsychiatric manifestations included organic brain syndrome, functional psychosis, and personality disorder. Laboratory tests showed elevated cerebrospinal fluid opening pressure and protein, negative cultures, and abnormal electroencephalograms and computerized axial tomography scans. Fourteen of 16 children with CNS manifestations are alive. Thirteen had a mean IQ of 89 by the Wechsler Intelligence Tests. Twelve are in educational programs. One required long-term psychiatric care. A residual neurologic abnormality, a seizure disorder, was present in 3. CNS involvement with SLE in children carries a favorable prognosis.

Pericarditis and cardiac tamponade in juvenile rheumatoid arthritis

Cardiac tamponade is a rare complication of juvenile rheumatoid arthritis. Three cases seen in the last two years at the Children's Hospital of Philadelphia are reported and compared to four previously reported cases. All three children had systemic-type juvenile rheumatoid arthritis with tachypnea, shortness of breath, and chest pain. Cardiac signs in these children included decreased heart sounds, pericardial friction rub, jugular venous distention, and pulsus paradoxus greater than 12 mm Hg. Roentgenograms of the chest showed cardiomegaly with bilateral pleural effusions. Electrocardiograms showed sinus tachycardia and nonspecific ST-T wave changes. Echocardiograms demonstrated pericardial effusions in all subjects and poor ventricular movements in one child. All three children were treated with short-acting anti-inflammatory drugs and/or prednisone. Pericardiocentesis was performed in two cases. There was no significant morbidity after a mean follow-up of two years.

Pulmonary manifestations of juvenile rheumatoid arthritis. A report of eight cases and review

Pleuropulmonary disease was seen in 4 per cent of patients with juvenile rheumatoid arthritis. Roentgenographic abnormalities seen in association with juvenile rheumatoid arthritis include: transient pneumonitis, interstitial reticular and nodular infiltrates, pleural and pericardial effusions, and patchy pleural infiltrates. Pathologic abnormalities seen in association with juvenile rheumatoid arthritis include pulmonary hemosiderosis, lymphoid follicular bronchiolitis, and lymphocytic interstitial pneumonitis. Patients with juvenile rheumatoid arthritis and pleural disease recover fully. In children with parenchymal disease, residual abnormalities include roentgenographic evidence of interstitial fibrosis and minimal abnormalities of pulmonary function.

A micromethod for the analysis of cryoglobulins via laser nephelometry: evaluation and comparison to C1q binding activity in autoimmune diseases in pediatrics

Quantitative determinations of cryoglobulins (IgG, IgA, IgM, and C3) were performed by a laser nephelometry microtechnique on 250 serum samples from a group of pediatric patients suspected of having immune complex-mediated disorders. Approximately 50% of these samples were cryoglobulin positive. Patients with cryoglobulins were examined as three separate groups: systemic lupus erythematosus, presumptive autoimmune disorders, and chronic bacterial or viral infections. Nearly all of these patients have mixed cryoglobulins. The relation of cryoglobulinemia with serum hypocomplementemia and renal involvement was examined in a group of systemic lupus erythematosus patients. High levels of cryoglobulins were found in patients with hypocomplementemia and anti-DNA antibodies without clinical evidence of nephritis. Highly significant correlations were oberved between C1q binding activity, presence of cryoglobulins, and serum hypocomplementemia in systemic lupus erythematosus patients. Only 60% of the cryoglobulin positive samples had immune complex demonstrable by C1q binding. Cryoglobulin analysis using the laser nephelometry microtechnique permits screening of pediatric patients for the presence of immune complex, permits detection of low levels of cryoglobulins, allows quantitative determination of the specific imunoglobulin classes in the precipitate, and requires only a very small amount of blood suitable for the pediatric population.

Salicylate therapy in juvenile rheumatoid arthritis. Dose, serum level, and toxicity

In a prospective study of aspirin therapy for 67 children with juvenile rheumatoid arthritis, we have found that (1) doses greater than 100 mg/kg/day of aspirin may be necessary to achieve therapeutic salicylate levels greater than 20 mg/dL; (2) no improvement in clinical remission rate is seen at salicylate levels greater than 30 mg/dL; (3) clinical toxicity to aspirin is of relatively low incidence (16%), and infrequently causes serious morbidity; (4) symptomatic SGOT elevations are common in the first three months after onset of therapy; and (5) these elevated SGOT levels generally return to normal despite continuation of therapy.

Neonatal presentation of I-cell disease

Two patients are described in whom the diagnosis of I-cell disease was established in early infancy. These patients lacked many of the clinical and radiographic features described in other children with this disorder. Differences between the neonatal and early childhood presentation of ICD are discussed.

Acute encephalopathy, streptococcal infection, and cryoglobulinemia

A 9-year-old girl had an acute encephalopathic illness characterized by disordered consciousness, seizures, and multiple cortical deficits. The acute illness was associated with serologic evidence of an antecedent streptococcal infection and the presence of a mixed cryoglobulin with specific antistreptococcal antibody activity. Although the patient had no other evidence of a systemic or central nervous system vasculitis, computerized tomography demonstrated changes compatible with a vasculitic process. Treatment with corticosteroids was associated with resolution of the cryoglobulinemia and complete clinical recovery.

Hapten-specific stimulation of secondary B cells independent of T cells

Treatment of spleen cell suspensions from immunized mice with anti-theta serum and complement before transfer to nonimmune irradiated recipients reduced the degree of in vitro stimulation by hapten-homologous carrier complexes by 90%, but did not decrease at all the number of isolated precursor cells stimulated by hapten on heterologous carriers. Thus, secondary B cells can be stimulated by low concentrations of multiply substituted hapten-carrier complexes in the apparent complete absence of specific T cells.