Dermatomyositis responding to treatment of associated toxoplasmosis

Prevalence of Toxoplasma gondii and Toxocara canis Among Myositis Patients in the Southwest of Iran

INTRODUCTION

Parasitic myositis is caused by some parasites, such as Toxoplasma gondii) T. gondii (and Toxocara canis (T. canis). So, the aim of the study was to evaluate the prevalence T. gondii and T. canis in patients with myositis and healthy individuals.

METHODS

A total of 108 samples were randomly selected as the control (54 healthy individuals) and test (54 myositis patients) groups. IgG and IgM antibodies (Ab) against T. gondii and IgG Ab against T. canis were measured by the enzyme-linked immunosorbent assay (ELISA). The detection of chronic and acute toxoplasmosis was performed by the ELISA IgG avidity. The presence of T. gondii in the blood was evaluated using the nested polymerase chain reaction (nested-PCR).

RESULTS

Of 108, 33 (30.6%) cases were positive for IgG against T. gondii that 19 (35.2%) and 14 (25.9%) were observed in myositis patients and healthy individuals, respectively (P=0.296). Of 19 positive cases, 12 (63.2%) and 7 (36.8%) cases were detected as chronic and acute toxoplasmosis, respectively, while, all positive cases in the control group had chronic toxoplasmosis (P=0.013). One (1.9%) sample was positive for anti- T. gondii IgM and two (3.7%) samples were positive for IgG against T. canis by the ELISA that these positive cases were observed only in myositis patients (P=1.000 P=0.495, respectively). B1 T. gondii gene was amplified in 12 (63.2%) and 1 (7.1%) in myositis patients and healthy subjects (P=0.001).

CONCLUSION

Our findings showed that there was a relatively high prevalence of acute toxoplasmosis in myositis patients in comparison with the control subjects in the Southwest of Iran.

Idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies are a group of systemic autoimmune syndromes characterized by striated muscle inflammation. Here, we discuss the clinical features of this group of conditions and review the recent developments in the understanding of the pathogenesis and immunogenetics of the idiopathic inflammatory myopathies. The role of myositis-specific autoantibodies and their clinical significance and an overview of management are also provided.

Mannose binding lectin (MBL) polymorphisms associated with low MBL production in patients with dermatomyositis

One theory for the pathophysiology of photosensitive autoimmune skin diseases is that photoinduction of tumor necrosis factor alpha (TNFalpha) secretion leads to keratinocyte apoptosis and translocation of previously sequestered cellular antigens that then activate the immune system. We previously found an association of the overproducing TNFalpha-308 A variant with adult dermatomyositis and with subacute cutaneous lupus erythematosus. Here we focused on mannose binding lectin (MBL), which is one of several proteins involved in clearance of apoptotic cells and could thereby lessen photosensitive autoimmunity. We examined three variant MBL polymorphisms associated with decreased MBL protein (Asp54, Glu57, and the LX promoter polymorphism) in adult dermatomyositis, subacute cutaneous lupus erythematosus, and discoid lupus, and controls. The variant Asp54 allele was positively associated with adult dermatomyositis in a dose-responsive fashion (p=0.0004), as was the Glu57 allele (p=0.004). None of the three variant MBL alleles considered individually was significantly associated with either subacute cutaneous lupus erythematosus or discoid lupus. In adult dermatomyositis patients homozygous for the wild-type TNFalpha-308G allele (GG), i.e., presumably without elevated TNFalpha production, 69% had at least two of the MBL polymorphisms, versus 20% of healthy GG controls (p=0.0011). Combinations of low-producing MBL variants were over-represented in adult dermatomyositis in a dose-responsive fashion (p=0.0002). In adult dermatomyositis patients with one variant TNFalpha-308 A allele (GA), 46% had at least two MBL polymorphisms, versus 7% of GA controls (p=0.0077). Thus, low-producing MBL genes are very strongly associated with adult dermatomyositis. Our model is that genetic polymorphisms leading to overproduction of apoptotic keratinocytes and then impaired clearance of these cells contribute to the pathogenesis of adult dermatomyositis, a photoinduced autoimmune skin disease.

Rheumatic manifestations of parasitic diseases

OBJECTIVES

To consolidate the spectrum and frequency of parasite-related rheumatic syndromes, which have largely been regarded as exceedingly rare by the general medicine, infectious disease, and rheumatology literature.

METHODS

A MEDLINE search was performed for articles on rheumatic syndromes related to parasitic infections published from 1966 through December 2000. Identified articles included clinical and epidemiologic studies describing cases of rheumatic syndromes associated with verified parasitic infection.

RESULTS

Rheumatologic syndromes, including inflammatory arthritis, inflammatory myositis, and vasculitis, have been described among multiple different parasite infections of all parasitic divisions, including Protozoa, Nematoda, and Platyhelminthes. Individual parasitic divisions are often associated with particular rheumatic syndromes, such as reactive arthritis and spondyloarthropathy, inflammatory or infectious myositis, and reactive or parainfectious vasculitis.

CONCLUSIONS AND RELEVANCE

Parasitic infection may underlie the clinical presentation of some rheumatic conditions. Given the continued and growing number of patients at risk for parasitosis by virtue of their country of origin, travel habits, and an immunocompromised state, potential parasitosis must be considered in patients undergoing evaluation for rheumatic complaints.

Toxoplasmic polymyositis revisited: case report and review of literature

Toxoplasmosis can cause polymyositis either by reactivation or by recent infection. Inconsistent response to antiprotozoal therapy has been the strongest argument against toxoplasmic polymyositis as a separate entity. We report a biopsy-proven case of toxoplasmic polymyositis in a cardiac transplant patient presenting with a severe proximal weakness, myopathic, electromyographic changes and ten-fold increase of anti-Toxoplasma antibodies. An early antiprotozoal therapy and plasmapheresis led to recovery. A review of previously reported cases of toxoplasmic polymyositis suggests that an early antiprotozoal therapy is the most important variable affecting the outcome of this disease. We propose that toxoplasmic polymyositis has two phases: acute, responsive to antiprotozoal therapy, and chronic, manifested by altered immune response requiring steroids. We suggest that all patients presenting with polymyositis should have serological tests for toxoplasmosis as a part of their initial evaluation and an early trial of antiprotozoal therapy in case of positive findings.

Rheumatic syndromes associated with parasites

A variety of musculoskeletal syndromes has been described in association with numerous parasitic infestations. Arthritis, enthesitis, myositis and vasculitis have been described in infected individuals resident in, or visitors to, endemic areas. The diagnosis of parasitic rheumatism is supported by poor response to anti-inflammatory drugs and improvement following antiparasitic treatment.

Current dermatologic therapy

This article reviews therapeutic advances reported in the English-language literature during 1991. Readers should review the original article in full before attempting any experimental or controversial therapy.