Day +18: An HLH comeback?

Sam's recent labs indicate that there may be some HLH activity in his body. The signals are mixed, however.

On the less promising side, Sam's ferritin and soluble IL-2 levels are elevated--not abnormally high, but higher than expected given his condition. Both are bio-markers for HLH, so both are red flags. In addition, Sam's triglycerides are abnormally high. This, too, is indicative of some kind of inflammation, including--although not necessarily--HLH.

On the other hand, the docs say HLH activity this soon after transplant would be unusual. Moreover, Sam's platelet count is healthy and rising. HLH attacks platelets, so a healthy platelet level would be inconsistent with HLH activity. Sam also recently tested positive for a (readily treatable) bacterial infection, and the associated inflammation could account for at least part of the ferritin and soluble IL-2 values, if not the triglycerides.

In short, we have mixed signals and need more data. Tomorrow Sam is scheduled to get another spinal tap (to see if there's evidence of HLH in his central nervous system) and his second bone marrow biopsy. Results, which we hope to see late Monday or early Tuesday, will tell us a lot more about what's going on.

It's ironic to be rooting for a bacterial infection, but I guess that's where we are.

We still have not yet seen results from the first chimerism (aka engraftment analysis) test, so we don't yet know how much of Sam's blood is his own and how much comes from the donor. Doctors are confident, however, that we will see continued evidence of good engraftment. Sam's donor was perfectly matched, and his blood counts would not be rebounding so quickly if the engraftment wasn't going according to plan.

In the meantime, here's Alyson and Rufus serenading Sam. Background melody provided by the mobile overlooking Sam's bed. Security courtesy of Mr. Shark.

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