Some observations on immunological status and immunodiagnosis in Bancroftian filariasis.

Filariasis displays a wide range of clinical and pathological manifestations, represented by asymptomatic carriers of microfilaria, symptomatic cases of filariasis with or without circulatory microfilaria and extreme cases of elephantiasis. The immunological status of the host is expected to play an important role in the genesis of the different manifestations. Diagnosis of filariasis is still a problem, since the only available test is based on examination of a night blood smear for microfilaria, which are often scanty or absent in the symptomatic cases. A study of the immune status of filarial subjects was performed with the ultimate object of understanding the mechanism of host resistance and developing a suitable immunodiagnostic test. Observations on certain cellmediated and humoral immune responses and on the feasibility of an ELISA test in the diagnosis of filariasis are discussed below.