<s>[INST] hi my grandson was in hospital w pneumonia a month ago. He had blood work 2 weeks ago which revealed low white blood cell count and false positive hiv.  I am so very worried.  I know his immune system is very low.  Please tell me what your diagnosis would be and my next step. Thank you. [/INST] HIWell come to HCMIf this is pneumonia then the white blood cell count would have been increased but as you said it is low so the pneumonitis is ruled out here false positive is not considered as diagnostic criteria and this is not taken into consideration, the test need to be repeated with the deferent methods, hope this information helps. </s>