Cell-bound complement activation products (CB-CAPs) have high sensitivity and specificity in pediatric-onset systemic lupus erythematosus and correlate with disease activity

OBJECTIVE

Elevated levels of cell-bound complement activation products (CB-CAPs) (C4d deposition on B lymphocytes (BC4d) and/or erythrocytes (EC4d)) are sensitive and specific in diagnosis and monitoring of adult systemic lupus erythematosus (SLE). Our objective was to evaluate the role of CB-CAPs for diagnosis and monitoring of pediatric-onset SLE (pSLE).

METHODS

A prospective cohort study of 28 pSLE and 22 juvenile arthritis patients was conducted. SLE disease activity was determined using a clinical Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) that excluded serologies. Autoantibodies were measured using solid-phase immunoassays, C3 and C4 using immunoturbidimetry, and CB-CAPs using quantitative flow cytometry. Abnormal CB-CAPs were defined as EC4d or BC4d above the 99th percentile for healthy adults (>14 and > 60 net mean fluorescence intensity (MFI), respectively). Performance characteristics of CB-CAPs were assessed using area under the curve (AUC) for receiver operating characteristics. Linear mixed effect models evaluated the correlation between CB-CAPs and clinical SLEDAI over 6 months.

RESULTS

BC4d yielded higher AUC (0.91 ± 0.04) than C3 (0.63 ± 0.08) and C4 (0.67 ± 0.08) ( p < 0.05). Abnormal CB-CAPs were 78% sensitive and 86% specific for diagnosis of pSLE (Youden's index = 0.64 ± 0.11). In contrast to BC4d, EC4d levels correlated with clinical SLEDAI ( p < 0.01).

CONCLUSION

CB-CAPs (EC4d and BC4d) have higher sensitivity and specificity than low complement in pSLE, and may help with diagnosis of pSLE. EC4d could provide a useful biomarker for disease activity monitoring.

Early versus later onset childhood-onset systemic lupus erythematosus: Clinical features, treatment and outcome

The objective of the study was to compare clinical features, treatment and disease outcome in patients with early versus later onset of childhood-onset systemic lupus erythematosus (cSLE). A retrospective matched cohort study of cSLE patients diagnosed between 1988 and 2008 and followed for a minimum of one year was conducted. Thirty-four pre-pubertal cSLE patients with disease onset prior to their 12th birthday were matched by ethnicity and year of diagnosis to 34 pubertal cSLE patients. The most common criteria at diagnosis in both groups were malar rash, arthritis, hematologic manifestations, and renal disease. After a mean follow-up of more than six years, a similar proportion of patients in the two groups were still prescribed corticosteroids (47% and 41%); patients in the early onset group required a significantly higher daily dose (0.6 mg/kg prednisone-equivalent versus 0.2 mg/kg, p < 0.05). There were no significant differences in organ involvement, disease activity and disease damage between the two groups, and severe complications occurred at similar rates. There were a greater number of admissions to the pediatric intensive care unit (PICU) in the early onset group (18 versus 5, p = 0.01), with time-to-event analysis demonstrating a significantly shorter disease duration from diagnosis to first PICU admission in the early onset group ( p < 0.001). While a similar proportion of patients in the early and later onset groups required treatment with cyclophosphamide, patients in the early onset group received treatment earlier in their disease course (mean 13.7 versus 19.9 months, p < 0.001). Early onset cSLE leads to earlier and more frequent PICU admission, earlier use of cyclophosphamide, and higher corticosteroid dose at long-term follow-up.

Minocycline and autoimmunity

Minocycline is the most widely prescribed systemic antibiotic for the management of acne. In the past several years, increasing attention has been paid to the drug, both for its potential use as a disease-modifying antirheumatic agent and for its propensity to engender untoward autoimmune reactions, including serum sickness-like disease, drug-induced lupus, and autoimmune hepatitis. This paper reviews the evidence for minocycline as an anti-inflammatory and immunomodulatory agent, its utility in the treatment of rheumatoid arthritis, and the spectrum of adverse reactions that have been ascribed to the drug in the past 5 years.

Comparative value of urinalysis, urine cytology and urine sIL2R in the assessment of renal disease in patients with systemic lupus erythematosus (SLE)

Serial immunological testing has been recently proposed for monitoring patients with lupus nephritis as routine serological tests have shown sub-optimal correlation with clinical status. To assess the value of urine cytology and urine sIL2R in the evaluation of patients with SLE, in particular those with lupus nephritis, we conducted a prospective double-blind study of 31 patients with SLE, during an 18-month period. A comparison of routine urinalysis with urine cytology and urine sIL2R was performed in 84 samples: 15 from patients without a history of renal involvement and 69 from patients with a history of renal involvement. A high urine cytology score (> or = 6), particularly in the presence of lymphoblasts, plasma cells or monocytes, was significantly associated with lupus nephritis in relapse. Urine sIL2R levels were significantly elevated during all SLE relapses, unrelated to the presence of renal involvement. Fifteen urine specimens were obtained at the time of a kidney biopsy: 9 with active lesions and 6 with inactive renal disease. UC score was 2.0 +/- 1.89 for those with absent activity, 8.4 +/- 3.4 for mild activity and 11.0 +/- 2.4 for moderate/severe activity (p < 0.001 between active vs inactive disease). No urinalysis parameter alone permitted distinguishing the degree of renal disease activity. In the subgroup of patients with renal disease urinalysis was overall less accurate than urine cytology or urinary sIL2R levels for predicting renal disease activity defined by biopsy. Urine cytology and urine sIL2R proved to be reliable measures of lupus activity.

Successful treatment of severe cytophagic histiocytic panniculitis with cyclosporine A

Cytophagic histiocytic panniculitis (CHP) can be a severe variant of Weber-Christian disease characterized by the histopathologic appearance of lobular panniculitis infiltrated by histiocytes containing blood cell fragments and by a clinical course with marked systemic features including multiorgan failure, hypertriglyceridemia, and coagulopathy, which may lead to death. Therapy of CHP includes standard treatment for panniculitis, such as antimalarials, plus immunosuppressives for more severe cases. The response to treatment, however, is unpredictable. In several recent reports, cyclosporine A has been successfully used to treat panniculitis. We report a patient and review the literature on CHP and the use of cyclosporine A as therapy. Published reports reveal that in instances of severe CHP when cyclosporine A was not given, 19 of 27 patients died (70% mortality). When severe CHP was treated with cyclosporine A, rapid remission was achieved in our patient and all five previously published cases (0% mortality). We believe cyclosporine A is the drug of choice in severe CHP and should be considered in all such patients.

Recurrent reflex sympathetic dystrophy as a manifestation of systemic lupus erythematosus

Reflex sympathetic dystrophy (RSDS) is a syndrome of hyperesthesia and vasomotor disturbance of an extremity, often following trauma or an inflammatory process. We describe a patient with systemic lupus erythematosus (SLE) and recurrent RSDS involving all 4 extremities at various times during her illness. Treatments, including corticosteroid use, physical therapy and at times sympathetic nerve blockade led to the resolution of each episode. We suggest the diagnosis of RSDS be considered in patients with connective tissue diseases who present with atypical pain syndromes not attributable to their primary illness.

Atypical arthropathy associated with Crohn's disease

Inflammatory bowel disease may be associated with a variety of rheumatologic abnormalities. The patterns of described enteropathic arthritis, not associated with the HLA B27 antigen, include non-deforming peripheral arthritis, bilateral, symmetric sacroiliitis, an on occasion, destructive monoarthritis. We report three patients with Crohn's disease and patterns of joint disease that have not been previously described. The patients ranged in age from 16 to 31 yr. In all cases, both joint and bowel disease were present since childhood. Antinuclear antibody, rheumatoid factor, and HLA B27 antigen determinations were negative. The distribution and pattern of joint disease were similar to that seen in rheumatoid arthritis. We propose that these cases do not represent coincident rheumatoid arthritis and Crohn's disease, but, rather, atypical manifestations of enteropathic arthritis.

Hypercalcemia during the resolution of calcinosis universalis in juvenile dermatomyositis

Dystrophic calcification is seen in more than 50% of children with juvenile dermatomyositis and tends to resolve spontaneously in some patients. Calcinosis universalis is the least common type of calcification seen and rarely regresses. We describe a boy with juvenile dermatomyositis and calcinosis universalis who developed hypercalcemia during spontaneous regression of dystrophic calcification. The treatment and possible mechanisms of this complication are discussed.

Safety and efficacy of methotrexate therapy for juvenile rheumatoid arthritis

Twenty-nine children with juvenile rheumatoid arthritis were studied to determine the safety and efficacy of methotrexate therapy. The initial dose of methotrexate averaged 7.1 mg/m2/wk and was given as a single, oral weekly dose or as three divided doses, each separated by 12 hours. Current antiinflammatory medications were continued; 25 of 29 children had had lack of efficacy, and 8 of 29 had toxic effects, with one or more prior drugs such as intramuscularly or orally administered gold, hydroxychloroquine, or D-penicillamine. Intolerable corticosteroid dependency or toxic effects were present in 18 of 29 cases. Methotrexate-treated patients were examined monthly; minimum treatment duration required to assess efficacy and toxicity was 6 months. The range of treatment duration was 8 to 39 months (mean 18.5 months). Efficacy was assessed by comparing pretreatment versus posttreatment fever and rash, swollen-joint counts, articular indexes, duration of morning stiffness, functional class, hemoglobin levels, and platelet counts. Treatment with methotrexate effectively controlled fever and rash in 83% of children with systemic juvenile rheumatoid arthritis, reduced morning stiffness by 63%, eliminated recalcitrant joint restriction in 48%, and reduced numbers of swollen joints and swelling indexes by 46% and 52%, respectively. No significant toxic effects were observed. Juvenile rheumatoid arthritis of long duration, or with major erosions, was more likely to be refractory to methotrexate therapy. We recommend earlier consideration of methotrexate in place of other slow-acting antirheumatic drugs for juvenile rheumatoid arthritis not responding well to usual therapy. Future studies should address potential methotrexate toxic effects in the lungs and reproductive system, as well as outcome after discontinuation of methotrexate treatment.

Lymphedema associated with juvenile rheumatoid arthritis

We describe 3 children with lymphedema associated with polyarticular juvenile rheumatoid arthritis (JRA). We review the occurrence of lymphedema in adult rheumatoid arthritis (RA) as well as other associations.

Nuclear imaging and clinical features of childhood reflex neurovascular dystrophy: comparison with adults

Reflex neurovascular dystrophy (RND) is less common in children than in adults, and differences in onset, clinical course, response to treatment, and degree of disability suggest a different pathogenesis. We have assessed the usefulness of nuclear imaging in 15 children with RND who were evaluated from March 1983 to September 1985. Abnormal findings on 3-phase bone scans were observed in 14 children, with diffusely decreased bone uptake at the symptomatic site being the most common observation. This contrasts sharply with previous reports of diffusely increased uptake in most adults with RND.

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.

Lyme arthritis in children. An orthopaedic perspective

The cases of forty-three children with clinical and serological evidence of Lyme arthritis that was diagnosed between August 1983 and July 1985 were evaluated. The mean length of follow-up was twenty months, with a range of five to thirty months. All of the children lived in or had visited an area where the disease was known to be endemic. Arthritis was the presenting feature in more than half of the children, and half of the children had initially consulted an orthopaedic surgeon, none of whom made the correct diagnosis. Only twenty patients had a history of erythema chronicum migrans, the characteristic rash that precedes the arthritis, and for only nineteen children was there any recollection of having been bitten by a tick. Three patients had Bell palsy and one had a popliteal cyst in conjunction with the arthritis. All of the patients had oligoarticular involvement. The knee was involved in all but two patients. Recurrent attacks of synovitis were common. Effusion was the only radiographic abnormality that was observed, and it was found in thirty-two patients. The sedimentation rate was elevated in thirty of thirty-six patients. Immunofluorescent serology for Lyme disease, which is sensitive and specific, was uniformly positive. Of thirty-three patients who were treated with oral administration of penicillin or tetracycline alone, thirty-one responded, while two patients who had recurrent attacks of the disease responded to parenteral administration of antibiotics. The remaining ten patients responded to combinations of orally and parenterally administered antibiotics. Longer follow-up is needed to further document the apparently low rate of relapse after antibiotic therapy in this young population.

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.

Treatment of Salmonella gastroenteritis in infants. The significance of bacteremia

During 1981, we treated 20 infants, less than 24 months old, for nontyphoid Salmonella (NTSal) gastroenteritis (GE). Blood cultures were obtained in 17 cases, and Salmonella bacteremia was demonstrated in 8 (47%). Of the 13 children 3 to 24 months of age, 7 (54%) had positive blood cultures. One child (8 months old) appeared septic. The patients with bacteremia were treated with parenteral ampicillin. All 20 infants recovered, and no focal infectious complications occurred. The incidence of bacteremia in NTSal GE is highest in children under 2 years of age. Previous reports have shown that the peak incidence occurs among infants less than 3 months of age. An infant with Salmonella bacteremia may be afebrile and show no symptoms of sepsis. In most cases, bacteremia is transient and does not alter the course of NTSal GE, but it may result in life-threatening complications such as septicemia and meningitis. Therefore we believe an infant with NTSal GE under 3 months old should have a blood culture and receive antibiotic treatment.