Bone problems are highly common among people with Gaucher disease, with symptoms including chronic bone pain, death of bone tissue due to insufficient blood supply to bones, and fractures, a long-term study shows.
The research, “Bone Manifestations in Gaucher Disease: A Monocentric Study of 128 Patients,” will be presented at the 2019 American College of Rheumatology (ACR)/Association for Rheumatology Professionals (ARP) meeting, set for Nov. 8-13 in Atlanta.
Bone symptoms are common among Gaucher disease patients, with problems including acute or chronic bone pain, risk of bone fracture, and death of bone tissue due to insufficient blood supply, a condition known as avascular necrosis (AVN).
Researchers in France evaluated the extent of bone manifestations in 128 Gaucher patients enrolled in the French Gaucher Disease Registry. Participants were followed at a single center for a median of 24.7 years.
Most patients (123) had type 1, while the remaining five had type 3 disease. Type 1 is the most common form of Gaucher and, unlike the other two types, does not usually involve neurological symptoms.
Nearly 80% of patients had the N370S mutation, previously associated with Gaucher disease, in at least one copy of the GBA gene.
Bone manifestations were the first symptoms in 11 patients (8.6%). At diagnosis, 31 patients (28.2%) had chronic bone pain and 16 (12.5%) had acute bone crisis.
During the almost 25 years of follow-up, 98 patients (76.6%) had clinical bone manifestations. In total, researchers registered 52 AVN episodes experienced by 30 patients, 14 of whom had multiple episodes. AVNs affecting the femur head (in the hip) were the most common, found in 33 cases.
Bone infarcts — essentially AVNs in the elongated part of bones instead of the bone head — were reported in 32 patients (25%), with multiple infarcts affecting 12 patients. Again, infarcts affecting the midsection of the femur were the most common (18 patients), followed by the tibia (13), pelvis (6), and humerus (upper arm, 3).
A total of 66 bone fractures occurred in 38 patients, more frequently in the upper limbs, followed by the lower limbs and vertebrae.
Erlenmeyer flask deformity of the femur, one of the early signs of bone involvement in Gaucher patients, was the most common alteration (36.4%) found in X-rays of 77 patients, followed by low bone density, or osteopenia, and bone lesions (23.4% each).
Bone density data were available from 66 patients, 11 of whom had osteoporosis (which makes bones extremely fragile) and 29 had osteopenia. Magnetic resonance imaging (MRI) from 119 patients showed bone marrow infiltration of Gaucher cells in 62 patients (52.1%).
At the time of the analysis, most patients (118) were alive and 106 were receiving either enzyme replacement therapy — 54 on Sanofi Genzyme’s Cerezyme (imiglucerase) and 31 on Shire‘s VPRIV (velaglucerase alpha) — or substrate reduction therapy with 21 patients on Cerdelga (eliglustat), also by Sanofi Genzyme.
“This retrospective monocentric study of 128 patients followed up in a [Gaucher disease] referral center during a median of 25 years provides useful information on bone involvement in [Gaucher], which occurs in a large majority of [Gaucher] patients,” the researchers stated.
