Will hair regrow after shock loss from PRP?

Unfortunately, shock loss has been reported after PRP with  A cell. It is one of the potential downsides of Acell. It is hard to predict whether all the follicles will return. Most likely they will. Find a hair loss expert.PRPHAIRMD.COM 

Shock Loss may occur after hair transplantation surgery. Individual results may vary. Shock loss is due to the loss of normal hair whether it is from donor site or recipient area.  It can occur with both FUE and strip procedures.  Usually if it occurs, it will take place in the recipient area.  
Shock loss from hair transplant can occur due to the following:
Anesthesia-  excessively long procedures taking longer than 12 hours can make shock loss more likely.  The repeated use of lidocaine, marcaine, and perhaps most importantly, epinephrine can affect nourishment of the hair.Traumatic harvest-  In strip surgery, traumatic harvest can cause shock loss.  Recipient area trauma- during the incision making process the hairs are either crushed or cut and damaged during the process. 
Ways to minimize shock loss are as follows:
Enhance the recipient’s bed and donor area environment.  Make your recipient environment better by the addition of growth factors and/or PRP to help reduce the extent of shock loss to native hairs.The use of Rogaine and Propecia can help shortened hair become more stable and less likely to fall out during procedure.9xRobotArtas- The latest version of the robot can make recipient sites and can determine angle of existing hair and help ensure that the angle will not damage existing hair. This is especially helpful in patients where you are transplanting hair to create density.Minimize anesthesia time and procedure time- We limit number of grafts to a safe number per session.  Extended periods of anesthesia and harvest times can increase patients chances of having shock loss. The 9x Robot harvests between 1000-1500 grafts per hour making it superior to previous additions and traditional FUE approaches.Best,
Anil Shah

A lot of doctors just see hair loss and start PRP. This is incorrect. The cause of the hair loss- the diagnosis- must be made before initiating any treatment for hair loss including PRP. Some types of hair loss resolve completely on their own while others need medical therapy. Shock loss from PRP can occur in about 2% of people- it is very uncommon. Its hard to predict who this will happen to or why.