Natural Killer (NK) Cell Deficiency: Clinical Phenotypes in Presence or Absence of Antibody Deficiency

Rationale:  Clinical manifestations of NK cell deficiency and its comorbidities remain poorly characterized. In an IRB approved retrospective chart review we identified patients with NK cell deficiency and divided them in two subsets defined by the presence or absence of antibody deficiency.  

Methods:  Forty patients with NK cell deficiency (decreased or absent function on three occasions) were identified, 29 had documented antibody studies. Patients were divided into two groups. Nineteen patients (group 2) had antibody abnormalities: either common variable immunodeficiency; specific antibody deficiency; or abnormal level of at least one immunoglobulin. Ten patients had normal antibody function (group 2).

Results:  Average age was 32 and 37 for group 1 and 2, respectively. Females were predominant in both groups, 63%, 100%. Comorbidities and infections included: allergic disease (31%, 20%), autoimmune disease (15%, 30%), cancer (15%, 10%), gastrointestinal disease (26%, 0%), documented total infections (100%, 90%), pulmonary disease (21%, 10%), sinus disease (47%, 70%), bacterial infections (36%, 20%), viral infections (15%, 0%), fungal infections (10%, 20%) and protozoal infections (10%, 0%). ANA was checked in 14 patients and was positive in three patients of group 2.

Conclusions:  Infections are predominant clinical manifestation in patients with NK cell deficiency. Immunologic abnormalities, particularly antibody deficiency seem to be an important comorbidity in patients with NK cell deficiency. Statistical significance is hampered by the low number of patients but it appears that there are no major differentiating aspects in the clinical phenotype of both groups.