Concomitant Myeloproliferative Disorders (MPD) and Amyloidosis

Background: The combination of MPD and amyloidosis is rare, and this patient population's clinical outcome is not well studied.

Methods: Pts with a MPD and amyloidosis were identified via an clinical note search engine that searches through the electronic medical records of patients seen at Mayo Clinic Rochester, Jacksonville, and Scottsdale between 1990 and 2016. Terms used included amyloid or amyloidosis, chronic myelogenous leukemia or CML, essential thrombocytopenia or ET, and polycythemia vera or PV. Demographic and clinical data were abstracted from the medical record. Pts with both disorders were analyzed and their mortality rates along with median time to death were calculated. Prevalences at the Mayo Clinic were calculated for the years 2014 and 2015.

Results: Twenty-three pts diagnosed with both a MPD and amyloidosis were identified. Thirteen (56.5%) were male, 10 (43%) were female. Eleven (47.8%) were initially diagnosed at the Mayo Clinic. Types of amyloidosis were as follows: Eleven (47%) had immunoglobulin light-chain (AL), four had localized (17%), two (8.7%) had wild-type transthyretin (ATTR), one (4.3%) had mutant ATTR, and five (21.8%) were unknown. Types of MPD were as follows: Seven (30%) had polycythemia vera (PV), seven (30%) had chronic myelogenous leukemia (CML), five (22%) had myelofibrosis, and four (17%) had essential thrombocytosis (ET). Fifteen (65%) were initially diagnosed with a MPD. Median time to last follow-up from second diagnosis was 1.7 years, and median time to death following second diagnosis was 1.4 years. The mortality rate was 87% in the total population. The median time to death for AL and PV was 2.7 years, AL and CML 1.0 years, and AL and ET 1.17 years. Myelofibrosis did not occur with AL. The most common combination was AL and PV, which accounted for five (22%) of the cases.

Treatment regimens for the patients with AL were varied. Multiple drugs were combined with dexamethasone including melphalan, velcade, pomalidomide, lenalidomide, doxorubicin, and revlimid. Cyclophosphamide, bortezomib, and dexamethasone (CyBorD) were used in two cases. The mean time to diagnosis of amyloidosis from symptom onset was 10.3 months.

Prevalences of AL and a MPD in 2014 and 2015 at the Mayo Clinic were 2.8% and 1.5%, respectively.

Conclusions: The mortality rate for the combined diagnoses is high. The most common combination of diagnoses was that of AL and PV, which was associated with a mean time to death of 2.7 years.