Is there anything besides hiv that leads to acquired immunodeficiency syndrome?

No : For all practical purposes the answer is no, but there are other means of depleting the CD4 count, some of which are of unknown source. They can produce a similar result as hiv, and we can do this as well with some of the drugs used to treat a variety of illnesses in medical practice. But when we talk about immunodeficiency syndrome we are almost always talking about HIV disease.