Any connection between low platelets and low cd4 t-cell counts? if a person has both should it be looked into further?

No: Reference ranges are set so that a few percent of healthies fall outside on either side. Only if you're way out of range should these be a concern. Your personal physician knows when to work these up. I trust you know your HIV status; advancing HIV infection is the only illness I know that is likely to drive both into the way-low, and if you're HIV-negative and near-normal range I'd relax.