Infection in Immunologically-mediated Diseases: A Review

Exacerbation of systemic lupus erythematosus related to cytomegalovirus infection

We report two patients with systemic lupus erythematosus (SLE) in whom cytomegalovirus (CMV) infection may have played a significant role in the exacerbation or onset of symptoms. The first patient had thrombocytopenia and the second had proteinuria. CMV infection was observed in both patients when their symptoms developed.

Invasive aspergillosis in systemic lupus erythematosus

Invasive aspergillosis is seldomly described in systemic lupus erythematosus. We present two cases of aspergillosis and review 21 cases reported between 1957 and 1994. The typical clinical presentation is fever and cough in a hospitalized SLE patient previously treated with corticosteroids, immunosuppressors, and broad-spectrum antibiotics. Unlike aspergillosis in other conditions, granulocytopenia is uncommon. Chest radiographs show diffuse or patchy infiltration of lung fields. Diagnosis was suspected premortem in 2 patients. Aspergillus fumigatus was identified or isolated in sputum or parenchimal tissues in the majority of cases. Twenty-two patients died (95%). The finding of hyphae in the sputum of a systemic lupus erythematosus patient with a suggestive clinical picture should lead to bronchoscopy, bronchoalveolar lavage, and lung biopsy. Proof of diagnosis will come from the demonstration of hyphae in tissues and isolation of aspergillus from tissue cultures. Long-term therapy with amphotericin B alone or in combination with fluorocytosine or itraconazole may help improve survival.

Rises in anti-double stranded DNA antibody levels prior to exacerbations of systemic lupus erythematosus are not merely due to polyclonal B cell activation

We investigated whether rises in anti-double stranded DNA (anti-ds DNA) antibody levels prior to disease exacerbations of systemic lupus erythematosus (SLE) are part of a restricted immune response or merely the consequence of polyclonal B cell activation. As possible inducers of polyclonal B cell activation, we analyzed, in addition, the role of clinically apparent infections in relation to changes in levels of anti-ds DNA and disease exacerbations. We prospectively followed 72 lupus patients who were examined for disease activity and infections at least every 3 months by history and physical examination according to a protocol. Once a month, we measured levels of IgG-class antibodies to an unrelated recall antigen (tetanus toxoid), levels of IgG-class antibodies to a viral antigen (cytomegalovirus late antigens [CMV-LA]), levels of total immunoglobulins G and M, and levels of anti-ds DNA (by ELISA and Farr assay). Thirty-three exacerbations and 31 infections were observed during a follow-up period of an average of 18.5 patient months. Twenty-four out of the 27 exacerbations accompanied by a positive test for anti-ds DNA were preceded by a significant rise in anti-ds DNA: in 17 cases by ELISA and in 22 cases by Farr assay. These 24 rises in levels of anti-ds DNA prior to the exacerbation were paralleled by a significant rise in levels of IgG-class anti-tetanus antibodies in 8 cases, anti-CMV-LA antibodies in 9 cases, total IgG in 7 cases, and total IgM in 15 cases. Median rise in anti-ds DNA, as measured both by ELISA and Farr assay, exceeded the median rise in anti-tetanus antibodies, anti-CMV-LA antibodies, and total IgG and IgM (P less than 0.0001). Only one infection was recorded within a period of 3 months prior to an exacerbation, whereas infections never occurred within a period of 3 months prior to a rise in anti-ds DNA. We conclude that rises in anti-ds DNA prior to exacerbations of SLE are largely due to preferential activation of anti-ds DNA-specific B cells and not merely to polyclonal B cell hyperactivity. Clinically significant infections are not related to rises in levels of anti-ds DNA nor to the induction of exacerbations in SLE.