Osteonecrosis in human immunodeficiency virus-infected patients may not be related to immune reconstitution

Thrombophilia in human immunodeficiency virus-infected patients with osteonecrosis: Is there a real connection? The first case-control study

Several reports have described an increased incidence of osteonecrosis in human immunodeficiency virus-infected patients (HIV+), but the cause has not been established. The association between thrombophilia and osteonecrosis in HIV+ was studied. A case-control study in HIV+, 19 cases and 38 controls, was designed. Magnetic resonance imaging was made in both groups to confirm or exclude hip osteonecrosis. The extensive tests of thrombophilia were measured, and the clinical data were recorded, nadir of CD4(+) cell count and well-known risk factors for osteonecrosis. Thrombophilia has been frequently found both in patients with and without osteonecrosis (thrombophilia, 68.4% vs 60.5%), but no specific thrombophilia tests were significantly associated with osteonecrosis. A low nadir of CD4(+) (<60 cells/microL) and corticoid use were significantly (P < .05) associated with osteonecrosis. In multivariate analysis, only nadir of CD4(+) <60 cells/microL remained a predictor of osteonecrosis (odds ratio = 7.33; 95% confidence interval, 1.80-29.82, P = .005). Thrombophilia might have a limited role in the development of osteonecrosis in HIV+. Nadir of CD4(+) <60 cells/microL and corticoid use were main factors.

Avascular Necrosis in HIV‐Infected Patients: A Case‐Control Study from the Aquitaine Cohort, 1997–2002, France

Using a case-control study design, we studied the factors associated with HIV-related avascular necrosis (AN). During a 6-year period, 12 symptomatic AN cases were validated, and each case was individually matched with 3 control cases. A conditional logistic regression model showed that current alcohol consumption and a history of steroid use were the only factors associated with the occurrence of AN.

Osteonecrosis in six HIV-infected patients receiving highly active antiretroviral therapy

OBJECTIVE

To report 6 cases of osteonecrosis in HIV-infected patients treated with highly active antiretroviral therapy (HAART) and compare the observed risk factors with those of published cases.

CASE SUMMARIES

Osteonecrosis was diagnosed between 1999 and 2002 in 6 of 417 HIV-infected patients in our department of infectious diseases. At the time of diagnosis, mean patient age was 42 years, and 5 patients had developed AIDS. Mean CD4+ lymphocyte count was 563.5 cells/mm(3) and viral load was undetectable (<50 copies/mL) in 5 patients. The patients' mean body mass index was 22.5 kg/m(2). Four had lipodystrophy. All were receiving HAART, including a protease inhibitor in 4 patients; the remaining 2 patients had a history of protease inhibitor treatment. Median time from the first antiretroviral therapy to osteonecrosis diagnosis was 46.5 months. Established risk factors were the use of corticosteroids in 2 patients and dyslipidemia in all patients. All of the patients developed pain and functional impotence of the hip or ankle joints. Osteonecrosis of the hip was bilateral in 4 cases. Three patients required surgical intervention, all of whom had favorable outcomes.

DISCUSSION

HIV-infected patients are at a higher risk for the development of osteonecrosis and are more likely to be exposed to predisposing factors to its development. The HAART implication as a predisposing factor remains controversial.

CONCLUSIONS

The pathogenesis of osteonecrosis in HIV-infected individuals may be multifactorial; the reasonable approach for clinicians consists of treating concomitant predisposing conditions that might further cause osteonecrosis.

[Immune restoration inflammatory syndromes]

Increase of prevalence of certain immunodeficiencies is caused by more frequent use of immunosuppresive treatment, by advances in supportive care of immunodeficient individuals and by the pandemic spread of HIV-infection respectively. Highly active antiretroviral treatment (HAART) is able to reconstitute the impaired immunity in the HIV-infected individual and therefore to reduce morbidity and mortality. On the other hand paradoxical exacerbation of inflammatory or opportunistic diseases may develop during immunoreconstitution. By their distinct pathophysiological, clinical and therapeutic particularities these disease have been summarized as Immune Restoration Inflammatory Syndromes (IRIS). This review summarizes the variety of immunoreconstitution disorders and describes possible diagnostic pitfalls. Potential therapeutic options and an algorithm for the classification of the syndrome are proposed.

Immune Restoration Inflammatory Syndromes: The Dark Side of Successful Antiretroviral Treatment

The prevalence of cellular immunodeficiency has increased due to rising use of immunosuppressive therapies and the pandemic spread of HIV infection. More recently, the introduction of highly active antiretroviral therapy (HAART) in HIV has led to significant immune reconstitution, even in patients with previously long-lasting secondary immunodeficiency. HAART reduces morbidity and mortality in HIV infection and also changes the clinical course of prevalent subclinical opportunistic infections or autoimmune diseases. Atypical inflammatory disorders develop after initiation of HAART and have been summarized as "immune reconstitution syndrome," "immune restoration disease," and "immune restoration inflammatory syndrome." However, diagnostic criteria and standards of therapy are yet to be defined. The awareness for these diseases is of increasing importance from a clinical point of view. This review summarizes the variety of immunoreconstitution disorders and describes possible diagnostic pitfalls. We also propose possible therapeutic options.

Osteonecrosis of the hip (Legg-Calvé-Perthes disease) in human immunodeficiency virus-infected children

OBJECTIVE

Osteonecrosis of the hip has been reported in human immunodeficiency virus (HIV)-infected adults; whether this is related to HIV infection or its treatment is unknown. There has been 1 report of osteonecrosis among HIV-infected children. Specifically, avascular necrosis of the hip consistent with Legg-Calvé-Perthes disease (LCPD) was reported in 3 HIV-infected children with AIDS from Spain in 1992. We evaluated the prevalence and incidence of LCPD, the pediatric equivalent of adult osteonecrosis of the hip, in HIV-infected children participating in a prospective cohort study of long-term outcomes in HIV-infected and HIV-exposed children-Pediatric AIDS Clinical Trials Group (PACTG) protocol 219.

METHODS

PACTG 219 enrolled 2014 HIV-infected and 849 HIV-exposed, uninfected children between April 1993 and September 2000. Children had periodic examinations with collection of clinical and laboratory data. The database was reviewed for reports of LCPD and other bone disorders. A prevalent case was defined as LCPD diagnosis preceding PACTG 219 enrollment and an incident case had to have occurred between enrollment and September 2000. A case-control study (matching on age, gender, and race/ethnicity, which are known to be associated with risk of LCPD and HIV infection status) was performed to investigate factors possibly associated with LCPD.

RESULTS

Six cases of LCPD (4 prevalent cases reported at study entry; 2 diagnosed during 5837 person-years of follow-up) were observed; LCPD was seen only in children with perinatal HIV infection. LCPD prevalence was 199 per 100 000 compared with an estimated general pediatric population prevalence of 23 per 100 000. Based on age-adjusted general population rates, the expected number of prevalent cases at PACTG 219 study entry would have been 0.44; the age-adjusted LCPD prevalence rate ratio was 9.0 (95% confidence interval [CI]: 8.3-9.7) for HIV-infected children compared with the general population. LCPD incidence was 34 per 100 000 person-years (95% CI: 0.42-124) compared with the estimated general population incidence of 6 per 100 000 person-years (95% CI: 5-7). Based on age-adjusted general population rates, the expected incidence of LCPD in PACTG 219 would have been 0.42; the age-adjusted relative risk of LCPD in HIV-infected PACTG 219 children was 4.8 (95% CI: 0.56-10.4). No cases were observed in uninfected children during 1919 person-years of follow-up on PACTG 219; the age-adjusted expected number of cases was 0.09. Median onset age was 7 years; 67% were of Hispanic or black race/ethnicity and 33% were female. Four of the 6 LCPD cases had received antiretroviral therapy before diagnosis; treatment was primarily with nucleoside reverse transcriptase inhibitors, and 2 had received protease inhibitors. Three of the LCPD cases had corticosteroid exposure before the diagnosis, but only 1 child had systemic exposure and the remaining 2 had topical exposure exclusively. In the case-control study, antiretroviral and corticosteroid therapy, CD4 cell percentage, birth weight, height for age and gender percentile, and triglyceride levels were not significantly associated with LCPD. However, the case-control study had limited power to evaluate possible associations.

CONCLUSION

Similar to HIV-infected adults, children with perinatal HIV infection have an increased risk for osteonecrosis of the hip, and clinicians should be alert to this diagnosis when HIV-infected children present with limp or hip pain. Whether LCPD is attributable to HIV infection itself, HIV-associated complications that could predispose to hypercoagulopathy, HIV-related therapies, or to the growth abnormalities in HIV-infected children is unknown and deserves additional evaluation.