Fatal Familial Leiner's Disease: A Deficiency of the Opsonic Activity of Serum Complement

The second family with a deficiency of phagocytosis enhancement (opsonization) related to a dysfunction of the fifth component of serum complement is reported. The clinical entity is similar to that of the first family, as well as that described by Leiner, in 1908. The four cardinal features are: (1) generalized seborrheic dermatitis; (2) intractable, severe diarrhea; (3) recurrent local and systemic infections, usually of gram-negative etiology; and (4) marked wasting and dystrophy. The diagnostic laboratory finding is the demonstration of deficient opsomc activity in the patient's serum. This demonstration requires a laboratory assay which measures uptake of a particle which requires C5 for total opsonization. Baker's yeast satisfies these requirements, whereas phagocytic assays utilizing such particles as erythrocytes, pneumococci, or latex particles are inadequate screening procedures for C5 deficiency. A functional assay is necessary, since immuno-chemical measurement of C5 has been normal in all deficient family members. Life-saving therapy has been administered to two patients with the disorder through the use of fresh plasma. Fresh plasma contains opsonically active C5, which is absent in 5-day-old stored bank blood. Based upon genetic and laboratory criteria, separate mechanisms of C5 dysfunction may be involved in the present family and that previously reported.