Serum immunoglobulins, complements and circulating immune complexes in oral lichen planus

Serum IgG, IgM, IgA, C3, C4 concentrations and circulating immune complexes (CIC) were measured in a series of 46 patients with oral lichen planus (LP). This investigation revealed a significant increase in the level of serum IgG in patients with oral LP as compared with 36 healthy subjects. In erosive LP, serum IgM was also elevated as compared with healthy subjects and patients with the non-erosive type. The results of this study did not support the suggestion that a humoral immunodeficiency underlies oral LP. Elevated serum level of IgM may be considered to represent secondary oral infection during mucosal erosion. The study also demonstrated a significant reduction in serum C4 in both variants of oral LP, but the C3 level was normal. A 3% polyethylene glycol precipitation (PEG-ppt) method was used, no significant amount of CIC could be detected in the patients. It is tempting to speculate that oral LP reflects an immunologic disorder in which serum IgG and C4 is disturbed. However, further investigation is needed to clarify the pathogenesis of oral LP.

Feasibility of computer screening of blood films for the detection of malaria parasites

This paper considers the feasibility of automatic screening procedures for detecting malaria parasites in blood smears prepared in the field. A simple programme for pattern recognition by computer has been developed for thin blood films that identifies parasites as densely stained particles within an erythrocyte. The parasites are detected correctly, but platelets falling accidentally within the outline of an erythrocyte and perhaps reticulocytes may be wrongly classified as parasites. The results indicate that automated detection of parasites is technically feasible but that the technique needs to be refined to reduce the incidence of false positives. A substantial increase in processing speed is required if the automatic procedure is to be economically feasible in screening programmes. The complexity of the equipment and the need for well prepared blood smears point to a possible use of the technique in laboratory checks but not under usual field conditions.