Circulating non-human microfilaria in a patient with systemic lupus erythematosus

A 12-year-old girl with systemic lupus erythematosus requiring steroid therapy was found to have a circulating microfilaria during an exacerbation of her illness. Morphologically, the microfilaria does not correspond precisely with any previously described species, though similarities exist between the patient's microfilaria and those of Dipetalonema reconditum of the dog and D. interstitium of the grey squirrel. The organism reported here is probably an undescribed species from a wild mammal. Although the association may be merely coincidental, this case suggests that compromised immunity might have led to this unusual infection with a non-human filaria.