BK nephritis in the non renal transplant setting

BK nephropathy got it's fame in kidney transplantation. Why can't this entity exist in native kidneys?
While reports have been seen following stem cell transplantation, no study had looked at this question till recently. A recent study in NDT presents 8 cases of BK nephritis in a native kidney setting.

The settings were:

1. HSCT
2. TB
3. Other hematologic malignancies
4. lung transplantation

What is interesting is that HIV patients don't get BK? Or there are scare reports. One study did find that HIV patients do shed BK virus. But most studies have found that they don't co exist. Some have suggested that they share the same co receptor.  Why don't we get full blown BK nephritis in this setting?- is it the altered immune setting or is it the one of the HAART meds that are protective ( and potentially a treatment for BK). Here is one case report in the literature.