Terry L. Moore

Thrombotic microangiopathic hemolytic anemia in systemic lupus erythematosus

Thrombotic microangiopathic hemolytic anemia (TMHA) is characterized by thrombocytopenia, microangiopathic hemolytic anemia, fever, neurological symptoms, and kidney involvement. It presents as thrombotic thrombocytopenic purpura (TTP) or hemolytic uremic syndrome (HUS). TMHA has been considered to occur only rarely in systemic lupus erythematosus (SLE). However, there has been an increase in the reporting of this association in recent years, and autopsy studies have suggested that TMHA may be underdiagnosed in SLE because of the similarity in symptoms. We report four patients with SLE-related TMHA and describe 24 more patients from a literature review. All patients were women, 50% had active SLE, 89% presented as TTP, and 11% presented as HUS. Those patients with active SLE had low complement levels. Antiphospholipid antibodies or lupus anticoagulant were positive in 5 of 8 cases. Patients treated with plasma infusions or plasmapheresis had a lower mortality rate at 25% compared with 57% mortality in patients who were not treated with plasma infusions or plasmapheresis. It is suggested that TMHA should be considered in any SLE patient presenting with neurological symptoms or renal failure associated with fever, hemolytic anemia, and thrombocytopenia. Early recognition and appropriate therapy with plasmapheresis may improve prognosis.

Parvovirus-associated arthritis.

Human parvovirus B19 is the cause of several distinct clinical syndromes. The most common is erythema infectiosum (fifth disease), a febrile exanthem occurring primarily in children. Recent studies have shown that parvovirus B19 can cause acute arthritis and occasionally a chronic arthropathy, both in children and adults. Parvovirus B19 DNA has been detected in studies in the synovial tissue of patients with rheumatoid arthritis, but other studies have varied in their findings. Recent studies also indicate a possible connective tissue disease–like syndrome with parvoviral infections. The common features of this syndrome are malar eruption, arthralgias, arthritis, and laboratory abnormalities including antinuclear antibody and rheumatoid factor positivity. However, the data indicate it is unlikely that B19 infection causes rheumatoid arthritis or systemic lupus erythematosus. Continued studies of the pathogenesis of acute and chronic parvoviral B19 infections and arthropathy may provide insights into virus–host interactions and mechanisms of joint disease and connective tissue disease.

Heart disease in systemic sclerosis

Primary cardiovascular manifestations of SSc include pericardial disease, myocardial disease, conduction abnormalities, and cardiac arrhythmias. Significant cardiac abnormalities are present in more than half of SSc patients at autopsy. As the frequency of subclinical cardiac involvement is now appreciated and noninvasive cardiac diagnostic modalities continue to improve, the ability to detect early asymptomatic involvement in SSc has improved. Two-dimensional echocardiography, radionucleotide imaging, and ambulatory ECG allow recurrent serial testing with virtually no morbidity. The current treatment of cardiac involvement in SSc is emperic and primarily directed at symptomatology. Large prospective randomized trials are needed to determine if preventive therapy is effective. With the advent of new immunological and cardiotropic agents and a better understanding of the primary disease process, our ability to alter the pathogenesis and final outcome of cardiac involvement in SSc should improve.

Rheumatoid factor-producing cells detected by direct hemolytic plaque assay.

Lymphocytes secreting anti-IgC antibodies, rheumatoid factors (RF), can be detected in the peripheral bloods, synovial fluids, and bone marrows of patients with seropositive rheumatoid arthritis by using a direct plaque-forming cell (PFC) assay with sheep erythrocytes sensitized with reduced and alkylated rabbit IgG hemolysin. The autospecific nature of the RF produced by RF-PFC was indicated by inhibition studies in which the order of patency was human IgG greater than rabbit IgG greater than bovine IgG. In metabolic studies puromycin, cycloheximide, and venblastine suppressed RF-PFC. Cyclic AMP and cyclic GMP were without effect. A need was recognized for using full tissue culture media during the cell separation and plaquing procedures to optimize detection of the RF-PFC. RF-PFC may appear in the blood of patients intermittently despite their continuing presence in the bone marrow. They have been found in the peripheral blood, especially during acutely exacerbating polyarticular synovitis, generalized vasculities, or generally active, aggressive disease. RF-PFC were found in synovial effusions of new or recrduescent acute synovitis. RF-PFC were observed to disappear from the peripheral circulation and the bone marrow during therapy with cytotoxic drugs. The data are consistent with the hypothesis that the appearance of RF-PFC in the peripheral blood represents an anamnestic response to transiently appearing antigen. The nature of the antigen is not specified. The bone marrow may be a site of origin of RF-PFC.

Parvovirus infection mimicking systemiclupus erythematosus

There are striking similarities between human parvovirus B19 (HPV-B19) infection and systemic lupus erythematosus (SLE): both may present with malar rash, fever, arthropathy, myalgia, cytopenia, hypocomplementemia, anti-DNA, and antinuclear antibodies (ANA). Therefore, it is difficult at times to differentiate HPV-B19 infection from SLE presentation or exacerbation. We report 4 cases of HPV-B19 infection mimicking SLE and review 10 other reported cases, all of whom were women. The similarity to a typical SLE presentation was indeed striking: most patients presented with rash, arthropathy, myalgia, fever, and positive ANA. In some cases, HPV-B19 infection seemed to exacerbate SLE rather then resemble it, and differentiation was difficult. Nearly all patients improved within several weeks. However, a few patients had symptoms and laboratory abnormalities lasting more than 6 months. The possibility of HPV-B19 infection should be entertained in patients presenting with SLE-like features.

Parvovirus infection mimicking systemic lupus erythematosusin a pediatric population

OBJECTIVES To assess the striking similarities of presentation in a pediatric population between human parvovirus B19 (HPV-B19) infection and systemic lupus erythematous (SLE). METHODS Medical records of seven patients (ages 6 to 15) with HPV-B19 infection were reviewed retrospectively. RESULTS Six of seven cases presented with a history of malar rash, and all seven had prolonged arthralgias and fatigue. Six of seven had a positive antinuclear antibody (ANA) titer ranging from 1:40 to greater than 1:640, with two patients having antibodies to Scl-70 and others to Sm, RNP, SS-A (Ro), or SS-B (La). The erythrocyte sedimentation rate (ESR) varied from 2 to 68 mm/h. Two patients presented with elevated rheumatoid factor (RF) titers of 24 and 271 IU/mL, respectively. All had elevated IgM antibody levels to parvovirus at the onset, and markedly elevated IgG levels when evaluated throughout their disease course. Over the course of 2 to 3 months, three improved, but the other four continued to have symptomatology for 14, 40, 78, and 120 weeks, respectively. Treatment was symptomatic, and no one developed classic SLE. CONCLUSIONS HPV-B19 infection in a pediatric patient group may present with SLE-like symptomatology and positive serology suggestive of SLE. The course of the disease is usually self-limited, though it may be prolonged in some for up to 120 weeks.

Presence of plasma complement regulatory proteins clusterin (Apo J) and vitronectin (S40) on circulating immune complexes (CIC)

The complement regulatory (CR) proteins clusterin and vitronectin bind to the membrane attack complex (MAC) and thus prevent cytolysis. In this report, we demonstrate the presence of both of these CR proteins on MAC bound to circulating immune complexes (CIC). We measured the amount of clusterin and vitronectin on MAC in plasma, also referred to as soluble MAC (SMAC), as well as on MAC bound to CIC (MAC–CIC), using antibody directed to polymerized C9 in systemic lupus erythematosus (SLE) patients. We observed a strong correlation among the quantities of SMAC and MAC–CIC. The amount of both clusterin and vitronectin associated with MAC–CIC was two‐ to threefold higher in comparison to the SMAC. Patients with high levels of clusterin and vitronectin demonstrated renal involvement. We hypothesize that these complement regulatory proteins besides regulating the insertion of MAC play other critical roles, in disease pathogenesis.

Autoantibody studies in juvenile rheumatoid arthritis

Early studies showed few immunologic abnormalities in juvenile rheumatoid arthritis (JRA) patients. There were no specific laboratory markers useful for diagnosis and assessment of the course of disease in JRA. Previous work showed an association of antinuclear antibodies (ANA) with early-onset pauciarticular disease and iridocyclitis. Similarly, the presence of 19S immunoglobulin (Ig) M rheumatoid factors (RF) was associated with late-onset polyarticular disease in girls. More recent studies have detected many unique autoantibodies. Newer assays show 19S IgM RF in up to 35% of JRA patients, although still mainly in girls with late-onset polyarticular disease. Hidden 19S IgM RF can be shown in up to 75% of JRA patients using different procedures, primarily in those with active polyarticular-or pauciarticular-onset disease. Immune complexes have been detected in JRA patients by means of different techniques; their presence usually correlates with active disease. Studies on a specific ANA in JRA have shown no common extractable nuclear antigen, but antihistone antibodies have been found in up to 75% of cases, again mainly in those with pauciarticular onset and iritis. Finally, a variety of unusual immunologic proteins have also been detected, including anti-ocular, anti-cellular, anti-cardiolipin, anti-perinuclear factor, and anti-collagen antibodies. This review evaluates the significance of these antibodies that can now be found in JRA.

Screening for Uveitis in Juvenile Rheumatoid Arthritis

BACKGROUND Uveitis associated with juvenile rheumatoid arthritis (JRA) is an important cause of visual impairment in children. Because uveitis is often asymptomatic in this age group, frequent ophthalmologic screening examinations are recommended. Recent reports have found a decrease in the prevalence and severity of uveitis in JRA when compared to older data. METHODS The charts of 52 consecutive patients with JRA seen over a 30-month period were retrospectively reviewed. RESULTS Eye examination identified uveitis in five (12%) patients. All patients with uveitis were female, ANA positive, and had pauciarticular-onset arthritis. Three patients had the onset of uveitis before the age of 2. All patients have maintained good visual acuity and have not developed serious sight-threatening ocular complications over the follow-up period. CONCLUSIONS Although the prevalence and severity of JRA-associated uveitis may be decreasing, we strongly recommend continued strict adherence to the current screening guidelines.

Immunopathogenesis of juvenile rheumatoid arthritis

The immunopathogenic mechanisms of juvenile rheumatoid arthritis (JRA) have been debated. A possible cellular-mediated hypothesis versus a possible B cell hyperreactivity have been entertained. This review will focus on some recent cellular work in JRA and also further evaluation of cytokine levels and their role in inflammation in JRA. Recent studies have evaluated the interrelationship of Th1/Th2 immune responses in the immunopathogenesis of JRA, and their effect on cytokine release. Studies have indicated a pro-inflammatory response in systemic-onset JRA manifested by increased secretion of interleukin-6, whereas an anti-inflammatory response has been noted by increases of IL-4 mRNA and IL-10 mRNA in pauciarticular-onset JRA. The continued finding of elevated levels of tumor necrosis factor-alpha (TNF-alpha) and its receptors in association with inflammatory activity has been seen. The recent use of a TNF fusion protein to block TNF-alpha activity in JRA has further contributed to this finding. Further studies on specific cytokines will be helpful in the future in trying to determine the different roles cytokines play in JRA subtypes and would contribute to the development of better therapeutic regimens.