RARE BONE DISORDER FOUND IN H.I.V. PATIENTS
By Lawrence Altman
The New York Times 9 Sept. 2000
An uncommon disorder that destroys bone is turning up with surprising
frequency among people infected with the AIDS virus, federal researchers
The researchers, from the National Institutes of Health, said they did
not know precisely what was causing the bone destruction among individuals
infected with H.I.V., the virus that causes AIDS. Nor do they know why the
disorder, which has led to hip replacement for some patients, is being
detected only now.
The disorder is known as osteo necrosis, or avascular necrosis,
because the death of bone results from a lack of blood supply. The disorder
can be painful and affect bones in many areas. The type found among people
infected with H.I.V. involves the hip and affected 4 percent of such people
in a study conducted at the clinical center of the health institutes, Dr.
Joseph Kovacs, one of the researchers, said in an interview.
"We're very concerned about this," Dr. Kovacs said, "because it is
potentially a very debilitating problem and we think its prevalence will
The problem was at first thought to be related to anti-H.I.V. drugs
like the protease inhibitors that were first marketed about four years ago,
but the researchers say that so far this link has not been proved. They
presented their report at a meeting of the Infectious Diseases Society of
America in New Orleans.
Also under investigation as possible causes are the use of hormones
like testosterone and short-term steroids, as well as cholesterol-lowering
drugs, the researchers said.
The bone problem is not related to the degree of immune deficiency from
AIDS or any particular pattern in the use of anti-H.I.V. drugs. Those
affected were more likely than others in the study to have been involved in
weight training and body building.
Osteonecrosis is a different condition from osteoporosis, or thinning
of the bones. Last February, scientists reported that many infected people
had developed osteoporosis as a complication of anti-H.I.V. therapy.
Osteonecrosis is also different from another recently detected problem
known as lipodystrophy, in which fat is redistributed so that
H.I.V.-infected people develop disfiguring cosmetic problems.
The institutes' researchers first noted the osteonecrosis problem
during a four-day period in May 1999 when two H.I.V. patients complained of
pain deep in the groin. One, a bicycle rider, said that he felt as if he
had pulled something, but that the condition did not get better with time
the way a pulled muscle would. Other patients limped from pain in the hip
Dr. Kovacs, one of those who detected the first cases, said his team
performed magnetic resonance imaging tests that confirmed the pain was due
to avascular necrosis.
"The two cases focused our attention," he said, "because until then we
had never detected a case" in the 17 years the institutes' clinical center
has cared for H.I.V. patients.
The institutes' doctors then found two more cases. All four patients
needed hip replacement surgery.
At about the same time, Dr. Kovacs said, his team learned that doctors
in Washington, San Francisco and elsewhere were detecting the bone disorder
in a small but increasing number of people with H.I.V.
The team checked with the Food and Drug Administration and learned it
had also noted a small but increasing number of reported cases of
osteonecrosis, Dr. Kovacs said. The cases reported to the F.D.A. were not
linked to any product.
Dr. Kovacs's team then conducted a study of about two-thirds of the
H.I.V.-infected patients cared for at the health institutes. Of the 339 who
volunteered for the study, 15, or 4.4 percent, were found to have avascular
necrosis of one or both hips. None of the 15 had symptoms, but many had
large areas of bone destruction, raising the possibility that the condition
had been detected in an early stage, Dr. Kovacs said.
For purposes of scientific comparison, the team did M.R.I. scans on 118
noninfected volunteers. None had the bone disorder.
The health institutes is conducting larger studies to determine how
many H.I.V.-infected people will develop osteonecrosis and how many will
need surgery for a total hip replacement. The studies also seek to find
what is causing people with H.I.V. to develop osteonecrosis, with the hope
that the answer will lead to prevention and treatment.
"Our concern is that this is going to be getting worse with time," Dr.
Kovacs said. "But we're hopeful that it won't be as bad as we think."