Thank you for your inquiry.
Unfortunately there is little that one can offer in a typical office setting related to the workup of a possible immunodeficiency disease involving cell-mediated immunity in a 4 month-old. I have copied for you below the suggested workup for cell-mediated immunity in the most recent Parameters dealing with primary immunodeficiency disorders published by the Joint Council. As you can see, the only things you might consider at this time are flow cytometry for the enumeration of T cell and natural killer cells and perhaps in vitro proliferation to mitogens and antigens.
In a 4 month-old continuing with the manifestattions you described, you should consider sending her to an immunodeficiency center for evaluation after doing the tests mentioned above.
Thank you again for your inquiry and we hope this response is helpful to you.
Cellular immune function
Flow cytometry to enumerate T cells and natural killer cells
Cutaneous delayed hypersensitivity
Enzyme assays (ADA, PNP)
FISH for 22q11 and 10p11 deletion
In vitro proliferative response to mitogens and antigens
Natural killer cell cytotoxicity
Cytokine production in response to mitogen or antigen stimulation
Expression of surface markers after mitogen stimulation
Source: Practice Parameter for the Diagnosis and Management of Primary Immunodeficiency. Ann Allergy 2005; 94:S1-S63.
Phil Lieberman, M.D.