Rifampicin-induced lupus erythematosus

Adverse reactions to first-line antituberculosis drugs

INTRODUCTION

Tuberculosis continues to be a major cause of morbidity and mortality worldwide. Currently available drugs are effective for treatment of the disease or latent infection, but may cause serious adverse effects.

METHODS

The authors reviewed the literature for side effects of five first-line antituberculous medications (isoniazid, rifampin, pyrazinamide, ethambutol and streptomycin). Incidence of the major side effects were compiled with particular attention to the incidence of isoniazid hepatotoxicity.

RESULTS

Hepatotoxicity to isoniazid is a serious problem. Although overall incidence may be decreasing, incidence averaged 9.2 per 1000 patients who were compliant, in multiple studies, with a case fatality rate of 4.7%. The incidence is higher with increasing age. Other serious adverse effects include dermatological, gastrointestinal, hypersensitivity, neurological, haematological and renal reactions. They can lead to drug discontinuation (in up to 10% of patients) or even more serious morbidity or mortality.

CONCLUSIONS

Side effects to antituberculosis drugs are common, and include hepatitis, cutaneous reactions, gastrointestinal intolerance, haematological reactions and renal failure. These adverse effects must be recognised early, to reduce associated morbidity and mortality.

Haplotype associations define target regions for susceptibility loci in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by diverse and variable clinical manifestations. The etiology of SLE is still unknown, but both environmental and genetic factors are involved. Recent genome-wide scans and candidate genes studies in different ethnic groups have already suggested susceptibility loci for SLE, but most of the genetic component remains unexplained. We have previously conducted a genome-wide scan in 35 Finnish families multiply affected with SLE. With 417 microsatellite markers, we detected suggestive linkage in regions on chromosomes 6q and 14q as well as HLA on 6p. The 14q locus has also been implicated in three previous genome scans on SLE, whereas a partially overlapping region on 6q was implicated in one previous study. In an effort to obtain additional evidence for susceptibility loci on 6q and 14q and in order to refine their positions, we performed fine mapping at 1 cM density across the suggestive regions of linkage. Our results show evidence for excess sharing of a haplotype on 14q and excess transmission of a haplotype on 6q. Our results are compatible with the idea of a founder effect for susceptibility genes in SLE in central eastern Finland and suggest a path to the isolation of the putative susceptibility genes.

Drug-induced, Ro/SSA-positive cutaneous lupus erythematosus

OBJECTIVE

To study the clinical and immunopathologic findings of drug-induced, Ro/SSA-positive cutaneous lupus erythematosus (CLE).

DESIGN

Retrospective medical and laboratory record review.

SETTING

Immunodermatology Division of Johns Hopkins Hospital (Baltimore, Md).

PATIENTS

Of 120 patients found to have anti-Ro/SSA antibodies by hemagglutination and/or double immunodiffusion, 70 had clinical and immunopathologic confirmation of CLE. Fifteen of these 70 patients had a history of new drug exposure, defined as less than 6 months, associated with disease development.

RESULTS

The disease-associated drugs included hydrochlorothiazide (5 patients), angiotensin-converting enzyme inhibitors (3 patients), calcium channel blockers (3 patients), interferons (2 patients), and statins (2 patients). The most common presentations were photodistributed diffuse erythema and subacute CLE-type lesions without evidence of significant systemic disease. All specimens revealed interface dermatitis and fine granular IgG deposition along the basement membrane zone and throughout the epidermis. Most patients experienced improvement or resolution of clinical lesions within 8 weeks and decrease of Ro/SSA titers within 8 months after discontinuation of drug treatment.

CONCLUSIONS

Antihypertensive drugs are the most commonly associated with Ro-positive CLE. Clinical and immunopathologic features of this drug-induced variant do not seem to differ from the idiopathic disease. In most cases, the disease improves or resolves on discontinuation of the offending drug treatment. It is not known if these drugs precipitate disease in patients who have subclinical disease. Drug-induced Ro/SSA-positive CLE should be included on the differential diagnosis in patients presenting with photosensitive or subacute CLE-type eruptions.