I am slowly going through my still unopened Science Daily updates…the August 27 issue (see: http://tinyurl.com/mmg7j5) contained a title that caught my interest: “Common blood disorder may not be linked to as many serious diseases.” The common blood disorder turns out to be MGUS.
In a nutshell, doctors have long been linking MGUS to more diseases than “just” multiple myeloma, amyloidosis and Waldenström macroglobulinemia. To my surprise, I discovered that there is a list of 75 other MGUS-associated diseases out there. 75! This list will almost certainly undergo some changes now…after the publication of the August 2009 Mayo Clinic Proceedings, which contain an interesting patient screening study declaring that the above-mentioned association is likely coincidental, in most cases, at least.
After reading the Science Daily summary, I went to have a look at the study (full study: http://tinyurl.com/lr55lc). Do you know that one of the MGUS-linked diseases is urticaria?! Eeek, just writing that word makes me itch all over!
Well, even though the full study is available online (above link), I thought I would take the time to go over a few points. Let’s see. The researchers confirmed that disorders of the bone, such as hip and vertebral fractures, osteoporosis, and hypercalcemia, are all significantly increased with MGUS, even in the absence of progression to multiple myeloma. We also confirmed known associations of MGUS with chronic inflammatory demyelinating neuropathy […] and autonomic neuropathy.
But they also found no significant association with MGUS in the 61 remaining disease diagnoses, an indication that most of these previously reported associations are either coincidental or clinically insignificant. So, in this patient population, 61 out of 75 diseases cannot be linked to MGUS. Interesting. Incidentally, see Table 2 (http://tinyurl.com/md35fy) for a complete list of diseases…you might be surprised by some of ’em…I was!
Also, have a look at Table 3 (http://tinyurl.com/mdzoqk) for a list of 20 new MGUS-associated diseases, including acute depression (!!!)…
In the Discussion part, we are also told that the frequency of osteoporosis and bone fractures is increased in patients with MGUS, independent of progression to myeloma. Eh.
Further on: The fact that we did not demonstrate a significant disease association with MGUS in such a large sample size is of major importance because it implies that these associations are likely not true associations, but rather coincidental ones. This has important therapeutic implications, because in some settings therapy has been administered to eradicate the monoclonal protein in the hopes that the associated disorder would be alleviated. Our study suggests that caution is needed.
Caution…indeed, I couldn’t agree more!