if his WBC and lymphocytes are both clinically low, it can mean a few different things and without any other information to puzzle piece, it’s difficult to say for sure, but here are some of the more likely possibilities:

-could be a low-grade, simmering chronic viral or bacterial infection
-could be an active bacterial infection (is he sick? UTI perhaps?)
-could be suppressed bone marrow function
-could be pancreatic insufficiency (body uses phagocytic white cells to break down food causing a decrease in white count)
-could be autoimmune in nature (systemic lupus – anemia is usually present as well)

Other conditions associated with decreased WBC/lymphocytes:
-hepatitis
-free radical diseases
-vitamin B12, B9 & B6 deficiency
-anterior pituitary dysfunction
-adrenal dysfunction
-parathyroid hyperfunction
-parasites (chronic)
-rheumatoid arthritis
-multiple food allergies

 you won’t always see these patterns with pancreatic insufficiency