Osteonecrosis in HIV: a case-control study

Osteonecrosis of the Femoral Head in Korean Patients with Human Immunodeficiency Virus Infection

Background

Osteonecrosis of the femoral head (ONFH) is a disabling condition that often necessitates total hip arthroplasty (THA). Although ONFH occurs more frequently among patients with human immunodeficiency virus (HIV) than among the general population, there is little epidemiological information regarding ONFH in Korean patients with HIV. In the present study, we aimed to investigate the incidence and clinical features of ONFH among Korean patients with HIV.

Materials and Methods

In this retrospective study, we reviewed the medical records of 1,250 Korean patients with HIV treated from January 1990 to December 2019. A standardised data collection sheet was used to obtain clinical information. Imaging data were analysed by a radiologist in accordance with the 2019 revised version of the Association Research Circulation Osseous (ARCO) staging system for ONFH.

Results

Among the 1,250 included patients, 13 patients (1.04%; 3 women, 10 men) were diagnosed with ONFH. The overall incidence of ONFH was 1.29 per 1,000 person-years (PYs) (95% confidence interval [CI]: 0.7 – 2.4 per 1,000 PYs). Median age among the 13 patients with ONFH was 47 years (interquartile range [IQR]: 41 – 57 years). The median duration since HIV diagnosis was 4.8 years (IQR: 2.3 – 10.1 years). The median CD4 cell count at the time of ONFH diagnosis was 381 cells/ mm³ (IQR: 161 – 551 cells/mm³). At the initial diagnosis of ONFH, 83.3% of patients exhibited bilateral involvement. ARCO stage 3 or 4 osteonecrosis was observed in 83% of patients. Among 22 hips, stage 1 ONFH was noted in 2 (9.1%), stage 2 ONFH was noted in 7 (31.8%), stage 3 ONFH was noted in 9 (40.9%), and stage 4 ONFH was noted in 4 (18.2%). THA was eventually performed in 84.6% of patients. Five (38.5%) patients had a history of steroid use, 4 (30.8%) patients had a history of alcohol abuse and 10 (76.9%) were smokers. Eight (61.5%) patients had a history of acquired immune deficiency syndrome-defining illness, including 7 with tuberculosis and 1 with pneumocystis pneumonia. Nine patients (69.2%) had a nadir CD4 cell count <200/µL, and 3 (23.1%) had a history of bone fracture. Overall, 84% of patients were exposed to antiretroviral therapy, while 54% had taken protease inhibitors for more than 1 year.

Conclusion

Considering that relatively high incidence of ONFH in patients with HIV, a high index of suspicion for those with risk factors and those with groin or hip pain for is required in HIV-infected patients.

Rheumatic diseases in HIV-infected patients in the post-antiretroviral therapy era: a tertiary care center experience

The aim of the study was to calculate the proportion of rheumatic diseases in HIV patients who were receiving ART and to identify association of the HIV medications with the development of rheumatologic diseases. We conducted a retrospective chart review during the period of 2010 to 2016. We identified 2996 patients as having chronic HIV infection and on ART, and we collected data regarding patient's demographic characteristics, comorbidities, CD 4 count, HIV viral load, and ART. One hundred thirteen out of 2996 HIV patients (3.8%) were found to have a rheumatic condition (mean age of 48.6 years, 83% male). The most frequent musculoskeletal condition was avascular necrosis (AVN) in 39 (1.3%), and the most frequent autoimmune condition was psoriasis in 28 patients (1%). Compared with the 200 HIV patients without any diagnosis of rheumatic disease were the older patients with rheumatic conditions (mean age of 48.9 vs. 42.7 years; p < 0.01), and had a longer duration of HIV infection (mean duration of 15.5 vs. 10.3 years; p < 0.01). The odds of rheumatic conditions were 1.7 times higher in males (relative to females). Those who received integrase inhibitors were more likely (63.3%) to develop rheumatologic manifestations relative to those who never received integrase inhibitors (21.6%; p < 0.01). The proportion of rheumatic diseases in HIV patients appears to be comparable to the prevalence in the US population. Older age, longer duration of HIV infection, and the use of ART regimens containing integrase inhibitors, appear to increase the risk of developing a rheumatic condition.

Associations Between Antiretroviral Treatment and Avascular Bone Necrosis: The Swiss HIV Cohort Study

Background

HIV-infected individuals have an increased risk of avascular bone necrosis (AVN). Antiretroviral therapy (ART) and particularly protease inhibitors (PI) have been implicated as a risk factor. We aimed to study the associations of ART with the occurrence of AVN among Swiss HIV Cohort Study participants (SHCS).

Methods

We used incidence density sampling to perform a case control study within the Swiss HIV Cohort Study (SHCS) comparing prospectively collected AVN cases and controls by conditional logistic regression analysis. To evaluate the effect of ART, multivariable models were adjusted for HIV transmission risk group, age, alcohol consumption, use of corticosteroids, CD4 nadir, maximum viral load, and pancreatitis.

Results

We compared 74 AVN cases and 145 controls. Associations with AVN were shown for heterosexual HIV acquisition (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.1–10), alcohol consumption (OR, 2.7; 95% CI, 1.3–5.7), and hyperlipidemia (OR, 3.6; 95% CI, 1.4–9.6). After adding ART substances to the multivariable base model, there was evidence of an association for treatment with tenofovir (TDF) >1 year (OR, 4.4; 95% CI, 1.4–14) with AVN. Neither exposure to specific frequently prescribed ART combinations or ART drug classes nor cumulative ART exposure showed any associations with AVN.

Conclusions

In the HIV-infected population, a combination of risk factors such as heterosexual HIV acquisition, moderate to severe alcohol intake, and hyperlipidemia seem to contribute to AVN. ART does not seem to be a relevant risk factor for AVN. The association of prolonged TDF exposure with AVN needs to be confirmed.

Update on current management of chronic kidney disease in patients with HIV infection

The prevalence of HIV-associated chronic kidney disease (CKD) varies geographically and depends on the definition of CKD used, ranging from 4.7% to 38% globally. The incidence, however, has decreased with the use of effective combined antiretroviral therapy (cART). A wide variety of histological patterns are seen in HIV-associated kidney diseases that include glomerular and tubulointerstitial pathology. In resource-rich settings, there has been a plateau in the incidence of end-stage renal disease secondary to HIV-associated nephropathy (HIVAN). However, the prevalence of end-stage renal disease in HIV-positive individuals has risen, mainly due to increased longevity on cART. There is a disparity in the occurrence of HIVAN among HIV-positive individuals such that there is an 18- to 50-fold increased risk of developing kidney disease among HIV-positive individuals of African descent aged between 20 and 64 years and who have a poorer prognosis compared with their European descent counterparts, suggesting that genetic factors play a vital role. Other risk factors include male sex, low CD4 counts, and high viral load. Improvement in renal function has been observed after initiation of cART in patients with HIV-associated CKD. Treatment with an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker is recommended, when clinically indicated in patients with confirmed or suspected HIVAN or clinically significant albuminuria. Other standard management approaches for patients with CKD are recommended. These include addressing other cardiovascular risk factors (appropriate use of statins and aspirin, weight loss, cessation of smoking), avoidance of nephrotoxins, and management of serum bicarbonate and uric acid, anemia, calcium, and phosphate abnormalities. Early diagnosis of kidney disease by screening of HIV-positive individuals for the presence of kidney disease is critical for the optimal management of these patients. Screening for the presence of kidney disease upon detection of HIV infection and annually thereafter in high-risk populations is recommended.

Rheumatoid arthritis in patients with HIV: management challenges

Over the past few decades, HIV has been transformed from a once-uniformly fatal disease to now a manageable but complex multisystem illness. Before highly active antiretroviral therapy (HAART), reports suggested that HIV-infected patients with rheumatoid arthritis (RA) would experience remission of their disease. It has now become clear that RA can develop in HIV-infected patients at any time, independent of HAART. Choosing the right medication to treat symptoms related to RA while avoiding excess weakening of the immune system remains a clinical challenge. Agents such as hydroxychloroquine and sulfasalazine might best balance safety with efficacy, making them reasonable first choices for therapy in HIV-infected patients with RA. More immune suppressing agents such as methotrexate may balance safety with efficacy, but data are limited. Corticosteroids such as prednisone may also be reasonable but could increase the risk of osteonecrosis. Among biologic response modifiers, tumor necrosis factor α inhibitors may balance safety with efficacy, but perhaps when HIV replication is controlled with HAART. Monitoring RA disease activity remains challenging as only one retrospective study has been published in this area. Those with HIV infection and RA can experience comorbidities such as accelerated heart disease and osteoporosis, a consequence of the chronic inflammatory state that each illness generates. Although HIV-infected patients are at risk for developing the immune reconstitution inflammatory syndrome when starting HAART, it appears that immune reconstitution inflammatory syndrome has a minimal effect on triggering the onset or the worsening of RA.

Early Outcomes of Primary Total Hip Arthroplasty for Osteonecrosis of the Femoral Head in Patients with Human Immunodeficiency Virus in China

Background:

Studies have reported that patients with human immunodeficiency virus (HIV) have a high incidence of osteonecrosis of the femoral head (ONFH). Total hip arthroplasty (THA) is an effective management of ONFH. However, little data exist regarding the use of THA for the HIV patients with ONFH in China. This study reviewed the outcomes of HIV-positive patients who underwent THA for ONFH, compared with HIV-negative individuals.

Methods:

The patients who underwent THA for ONFH from September 2012 to September 2014 in Beijing Ditan Hospital, Capital Medical University were retrospectively studied. Twenty-eight HIV-positive patients and 35 HIV-negative patients underwent 48 THAs and 45 THAs with cementless components, respectively. Medical records and follow-up data were reviewed. Harris Hip Score (HHS) was applied to evaluate the pain and function of the hips before and after THA. Complications such as wound healing, surgical site infection, deep venous thrombosis, pulmonary embolism, sepsis, mortality, and complications from the prosthesis were reviewed. The operation time, blood loss, and hospital stay were compared between the two groups.

Results:

The mean follow-up period was 19.5 ± 5.8 months (ranging from 6 to 30 months). The mean age of the HIV-positive patients with osteonecrosis at the time of surgery was 35 years old, which was significantly lower than that of the HIV-negative group (42 years old) (P < 0.05). The HIV-positive patients underwent surgery a mean of 2.5 years after their original symptoms, which was significantly shorter than the HIV-negatives’ (mean 4 years) (P < 0.05). Among HIV-positive patients, the prevalence of being male and rate of bilateral procedures were significantly higher than those in the HIV-negative group (P < 0.05). The operation time in HIV-positive patients was significantly longer than that in HIV-negative patients (P < 0.05). There were no significant differences in blood loss or hospital stay between the two groups (P > 0.05). The HHSs of two groups significantly improved after THAs (P < 0.05), without significant difference between two groups. No wound complication, sepsis, mortality, prosthesis complication, and occupational exposure occurred, except for two cases of heterotopic ossification and one case of humeral head necrosis.

Conclusions:

ONFH is more likely to occur bilaterally in younger HIV-positive males. The development of osteonecrosis seems faster in HIV-positive patients than in HIV-negative patients. This should be cautionary for asymptomatic HIV-positive patients with low viral RNA level and in the primary HIV stage. Despite longer operation times in the HIV-positive patients than in the HIV-negative patients, THA is still a safe and efficient approach to treat ONFH in HIV-positive patients. The incidence of complications is much lower than previously reported. However, the long-term follow-up is needed.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

HIV and its effects on bone: a primer for rheumatologists

PURPOSE OF REVIEW

As patients with HIV are living longer because of effective treatments, rates of comorbid chronic diseases such as bone complications are increasing. There is a growing body of literature showing increased rates of osteopenia and osteporosis in the HIV population. Less is known about the risk of fracture, as well as other bone complications, such as avascular necrosis (AVN).

RECENT FINDINGS

Increased rates of osteopenia and osteoporosis are seen in the HIV population, likely secondary to an interaction of traditional osteoporotic and HIV-specific risk factors, and possibly the effect of antiretroviral therapy (ART). There are conflicting recent data as to whether the decrease in bone mineral density seen in the HIV population, specifically with particular ART regimens, translates into an increased risk of fracture. Conflicting evidence emerges from recent studies exploring whether supplementation of vitamin D and calcium can prevent the bone loss seen with specific ART regimens.

SUMMARY

Bone disease is common in the HIV population, and will likely be a medical problem increasingly seen by rheumatologists. The role of ART regimens on bone complications such as fracture and AVN is unclear, and further research in this area as well as possible prevention strategies are needed.

Pulsed electromagnetic fields stimulation prevents steroid-induced osteonecrosis in rats

Background

Pulsed electromagnetic fields (PEMF) stimulation has been used successfully to treat nonunion fractures and femoral head osteonecrosis, but relatively little is known about its effects on preventing steroid-induced osteonecrosis. The purpose of the study was to investigate the effects of PEMF stimulation on the prevention of steroid-induced osteonecrosis in rats and explore the underlying mechanisms.

Methods

Seventy-two male adult Wistar rats were divided into three groups and treated as follows. (1) PEMF stimulation group (PEMF group, n = 24): intravenously injected with lipopolysaccharide (LPS, 10 μg/kg) on day 0 and intramuscularly injected with methylprednisolone acetate (MPSL, 20 mg/kg) on days 1, 2 and 3, then subjected to PEMF stimulation 4 h per day for 1 to 8 weeks. (2) Methylprednisolone-treated group (MPSL group, n = 24): injected the same dose of LPS and MPSL as the PEMF group but without exposure to PEMF. (3) Control group (PS group, n = 24): injected 0.9% saline in the same mode at the same time points. The incidence of osteonecrosis, serum lipid levels and the mRNA and protein expression of transforming growth factor β1 (TGF-β1) in the proximal femur were measured 1, 2, 4 and 8 weeks after the last MPSL (or saline) injection.

Results

The incidence of osteonecrosis in the PEMF group (29%) was significantly lower than that observed in the MPSL group (75%), while no osteonecrosis was observed in the PS group. The serum lipid levels were significantly lower in the PEMF and PS groups than in the MPSL group. Compared with the MPSL and PS groups, the mRNA expression of TGF-β1 increased, reaching a peak 1 week after PEMF treatment, and remained high for 4 weeks, then declined at 8 weeks, whereas the protein expression of TGF-β1 increased, reaching a peak at 2 weeks after PEMF treatment, and remained high for 8 weeks.

Conclusions

PEMF stimulation can prevent steroid-induced osteonecrosis in rats, and the underlying mechanisms involve decreased serum lipid levels and increased expression of TGF-β1.

Endocrine complications of human immunodeficiency virus infection: hypogonadism, bone disease and tenofovir-related toxicity

Treatment with highly active antiretroviral therapy (HAART) has revolutionized care of patients with HIV infection. The cost of increased survival has been antiretroviral toxicity and increasing age-related co-morbidities that include significant metabolic issues. Hypogonadism was first described in the setting of advanced AIDS and can be primary or secondary. Data regarding treatment largely concern patients with wasting. Varied syndromes involving bone have been described in patients with HIV including osteonecrosis, low bone mineral density (BMD) and osteoporosis, and rarely osteomalacia. Low BMD leading to osteoporosis is the most common bone pathology and may be as a result of HIV infection, drug toxicity or co-morbidities. However, increasingly fragility fractures are reported in HIV-infected patients, suggesting bone demineralization in this population is of clinical relevance. Further research is required to understand its pathogenesis and determine effective management; however, initiation of antiretroviral therapy seems to accelerate (in the short-term) bone demineralization. One particular antiretroviral agent, tenofovir is widely used and is potentially implicated as having a greater role in long-term bone and renal dysfunction. As this population ages, screening for low BMD will become increasingly more important.

Osteonecrosis in human immunodeficiency virus (HIV)-infected patients: a multicentric case-control study

Osteonecrosis (ON) is a rare disabling complication occurring in patients with human immunodeficiency virus (HIV) infection at a higher frequency than in the general population despite effective combination antiretroviral therapy being made available, as recently documented by several retrospective studies. We designed a multicentric case-control study among HIV-infected patients cared for at institutions in the Italian CISAI group (Italian Study Group for Adverse Events in HIV Infection) to search for additional predictors of ON in this special population. All centers which observed at least one case of ON were requested to report data for central re-evaluation. Parallel HIV-positive, ON-free controls were randomly selected and matched with confirmed cases of ON for sex, age and CD4 T-cell counts at the time of HIV diagnosis. Fifteen cases and controls were included in the final sample. Univariate statistical analyses revealed a significant association between ON and exposure to steroids (P = 0.001), exposure to one or more drugs in addition to HAART (Highly Active Anti-Retroviral Therapy) (P = 0.03), high titers of total serum IgE (P = 0.02), loss of working ability (P = 0.03), triglycerides levels over 200 mg/dL before antiretrovirals (P = 0.03) and cholesterol levels over 200 mg/dL before and after antiretrovirals (P = 0.03 and 0.05, respectively). High serum IgE levels and loss of working ability in advance of ON appeared for the first time as possible predictors of ON in HIV patients, while long-term exposure to steroids, combined hyperlipemia and chronic treatment with other drugs in addition to antiretrovirals were confirmed. Predicting and preventing ON in the individual HIV-infected patient is therefore a clinically challenging opportunity.

Operations about hip in human immunodeficiency virus-positive patients

BACKGROUND

The number of human immunodeficiency virus (HIV)-infected patients is increasing constantly, and it is well known that there is a significantly high prevalence of osteonecrosis of the femoral head in HIV-infected patients. Therefore, it is important to develop methods that can ensure the safety of both the patients and medical personnel who participate in surgery on HIV-infected patients. Recently, the authors performed 8 procedures on 5 HIV-infected patients. This paper reports our experience.

METHODS

This study examined the medical records and radiological studies of 5 HIV-infected patients who had undergone surgery around the hip joint from January, 2005 to September, 2007. During the procedures, their mean age was 38.6 years (range, 23 to 53 years) and all were male. Four of them were under an anti-retroviral therapy program. The reasons for the operations were nonunion of the femoral shaft after trauma in two patients and osteonecrosis of both femoral heads in three. One autologous bone grafting, one screw fixation with autologous bone grafting, five total hip replacement arthroplasties, and one multiple drilling were performed. All procedures were carried out according to the guidelines of HIV infection control made by the Korea Centers for Disease Control and Prevention. The mean follow-up period was 16.6 months (range, 4 to 37 months).

RESULTS

The preoperative CD4 count was 130 in one patient, and 200 to 499 in the other 4. The viral loads were 15100 and 420 in two patients, and negative in the other 3. Bony union was achieved in those who had undergone autologous bone grafting. There were significant improvements in both the Harris Hip Score and functional state in those who had total hip replacement arthroplasty. There were no immediate postoperative complications, such as infection. During the follow-up period, one patient died from esophageal variceal bleeding. However, no surgery-related complications were observed in the other 4 patients.

CONCLUSIONS

There were no significant complications in HIV-infected patients after the operations around the hip joint when their preoperative immunity was optimal. In addition, the safety of medical personnel can be assured when the operation is performed in line with the guidelines of HIV infection control.

SAS weekly rounds: avascular necrosis

Osteonecrosis of the femoral head is a condition that affects upwards of 10,000 individuals in the USA each year. The peak incidence is in the fourth decade of life, and overall, there is a male preponderance. The condition accounts for up to 12% of total hip arthroplasties performed in developed countries. The etiology can be traumatic or non-traumatic, with 90% of atraumatic cases attributed to corticosteroid therapy or excess alcohol consumption. Osteonecrosis of the femoral head reflects the final common pathway of a range of insults to the blood supply and ultimately results in femoral head collapse, acetabular involvement, and secondary osteoarthritis. Currently, conservative treatment options, which aim to correct pathophysiologic features allowing revascularization and new bone formation, appear to be able to delay but not halt the progression of this condition. As a consequence of femoral head osteonecrosis, many individuals undergo surgical treatments including: core decompression, osteotomy, non-vascularized bone matrix grafting, free vascularized fibular grafts, limited femoral resurfacing, total hip resurfacing, and total hip arthroplasty.

Glucocorticoids in osteonecrosis of the femoral head: a new understanding of the mechanisms of action

Glucocorticoid (GC) usage is the most common non-traumatic cause of osteonecrosis of the femoral head (ON). Despite the strong association of GC with ON, the underlying mechanisms have been unclear. Investigators have proposed both direct and indirect effects of GC on cells. Indirect and direct mechanisms remain intimately related and often result in positive feedback loops to potentiate the disease processes. However, the direct effects, in particular apoptosis, have recently been shown to be increasingly important. Suppression of osteoblast and osteoclast precursor production, increased apoptosis of osteoblasts and osteocytes, prolongation of the lifespan of osteoclasts and apoptosis of endothelial cells (EC) are all direct effects of GC usage. Elevated blood pressure through several pathways may raise the risk of clot formation. High-dose GC also decreases tissue plasminogen activator activity (t-PA) and increases plasma plasminogen activator inhibitor-1 (PAI-1) antigen levels increasing the procoagulant potential of GC. Inhibited angiogenesis, altered bone repair and nitric oxide metabolism can also result. Also, GC treatment modulates other vasoactive mediators such as endothelin-1, noradrenalin and bradykinin. Thus, GCs act as a regulator of local blood flow by modulating vascular responsiveness to vasoactive substances. Vasoconstriction induced in intraosseous femoral head arteries causes femoral head ischemia. GCs also cause ischemia through increased intraosseous pressure, which subsequently decreases the blood flow to the femoral head by apoptosis of ECs as well as elevating the level of adipogenesis and fat hypertrophy in the bone marrow. It is difficult to predict which patients receiving a specific dose of GC will develop ON, indicating individual differences in steroid sensitivity and the potential of additional mechanisms. The textbook model of ON is a multiple hit theory in which, with a greater number of risk factors, the risk of ON increases. While more effort is needed to better comprehend the role of GC in ON, newer data on GC action upon the endothelial cell and the regional endothelial bed dysfunction theory sheds new light on particular GC mechanisms. Better understanding of GC pathomechanisms can lead to better treatment options.

Rationale for prostaglandin I2 in bone marrow oedema--from theory to application

Introduction

Bone marrow oedema (BME) and avascular osteonecrosis (AVN) are disorders of unclear origin. Although there are numerous operative and non-operative treatments for AVN, pain management in patients with AVN remains challenging. Prostaglandins play an important role in inflammatory responses and cell differentiation. It is thought that prostaglandin I₂ ([PGI₂] or synonoma prostacyclin) and its analogues promote bone regeneration on a cellular or systemic level. The purpose of this study was to assess the curative and symptomatic efficacy of the prostacyclin analogue iloprost in BME and AVN patients.

Method

We are reporting on 50 patients (117 bones) affected by BME/AVN who were treated with iloprost. Pain levels before, during and 3 and 6 months after iloprost application were evaluated by a visual analogue scale (VAS). The short form(SF)-36 health survey served to judge general health status before and after treatment. Harris Hip Score (HHS) and Knee Society Score (KSS) were performed as functional scores and MRI and X-rays before and 3 and 6 months after iloprost application served as objective parameters for morphological changes of the affected bones.

Results

We found a significant improvement in pain, functional and radiological outcome in BME and early AVN stages after iloprost application, whereas patients with advanced AVN stages did not benefit from iloprost infusions. Mean pain level decreased from 5.26 (day 0) to 1.63 (6 months) and both HHS and KSS increased during follow-up. Moreover, the SF-36 increased from 353.2 (day 0) to 560.5 points (6 months). We found a significant decrease in BME on MRI scans after iloprost application.

Conclusions

In addition to other drugs, iloprost may be an alternative substance which should be considered in the treatment of BME/AVN-associated pain.

Influence of antiretroviral drugs on the pharmacokinetics of prednisolone in HIV-infected individuals

BACKGROUND

Corticosteroids are cytochrome P450 3A4 substrates, which have been associated with toxicities in patients receiving cytochrome P450 3A4 inhibitors such as human immunodeficiency virus protease inhibitors. In a study in healthy volunteers, ritonavir significantly increased prednisolone exposure.

METHODS

We investigated the influence of antiretroviral (ARV) medications on prednisolone pharmacokinetics in 3 groups of 10 human immunodeficiency virus-infected subjects. One group received lopinavir/ritonavir, and another efavirenz, as part of their ARV regimen; a third group did not receive ARV medications. Each subject received a single 20-mg prednisone dose followed by serial blood sampling for prednisolone. Prednisolone pharmacokinetics were compared among the groups.

RESULTS

Area under the concentration-time curve was significantly lower in efavirenz recipients versus subjects receiving lopinavir/ritonavir (geometric mean ratio = 0.60, P = 0.01). Average prednisolone area under the concentration-time curve was higher in subjects taking lopinavir/ritonavir versus subjects not on ARVs; however, this difference was not significant (P > 0.05).

CONCLUSIONS

These data indicate that prednisolone concentrations may fluctuate widely when human immunodeficiency virus-positive individuals established on efavirenz therapy change to lopinavir/ritonavir or vice versa.

The incidence and natural history of osteonecrosis in HIV-infected adults

BACKGROUND

Osteonecrosis is increasingly recognized as a debilitating complication of human immunodeficiency virus (HIV) infection, but the natural history has not been well described. We previously documented a high prevalence (4.4%) of magnetic resonance imaging (MRI)-documented osteonecrosis of the hip in a cohort of 339 asymptomatic HIV-infected patients. The present study was designed to determine the incidence of newly diagnosed osteonecrosis in this cohort and to describe the natural history of osteonecrosis in HIV-infected patients.

METHODS

Asymptomatic HIV-infected patients with a previous hip MRI negative for osteonecrosis underwent follow-up MRI. Patients with asymptomatic or symptomatic osteonecrosis were enrolled in a natural history study, which included serial MRIs and a physiotherapy follow-up.

RESULTS

Two hundred thirty-nine patients underwent a second MRI a median of 23 months after the initial MRI. Osteonecrosis of the femoral head was diagnosed in 3 patients (incidence, 0.65 cases per 100 person-years). During the period of January 1999 through April 2006, symptomatic hip osteonecrosis developed in 13 clinic patients (incidence, 0.26 cases per 100 person-years). Among 22 patients enrolled with symptomatic hip osteonecrosis, 18 had bilateral involvement of the femoral heads, and 7 had osteonecrosis involving other bones. Two (11%) of 18 asymptomatic patients and 13 (59%) of 22 symptomatic patients underwent total hip replacement. The percentage of involvement of the weight-bearing surface of the femoral head and the rate of progression to total hip replacement was significantly greater (P<.001) in symptomatic patients than in asymptomatic patients.

CONCLUSIONS

HIV-infected patients are at approximately 100-fold greater risk of developing osteonecrosis than the general population. Disease progression is slower in asymptomatic patients than in symptomatic patients. Given the high frequency of total hip replacement in symptomatic patients, studies to assess preventive and treatment strategies are essential.

Contrast-Enhanced MRI and Micro-CT Adopted for Evaluation of a Lipid-Lowering and Anticoagulant Herbal Epimedium-Derived Phytoestrogenic Extract for Prevention of Steroid-Associated Osteonecrosis

We developed an alternative steroid-associated osteonecrosis (ON) rabbit model using a combination of a single injection of low-dose lipopolysaccharide (LPS) and three subsequent injections of pulsed high-dose methylprednisolone (MPS).The usefulness of this experimental ON model was evaluated using both conventional and advanced bio-imaging techniques, including contrast-enhanced dynamic MRI and a high-resolution micro-CT. Details on establishment of methodology are described, which were adopted into an efficacy study on a herbal Epimedium-derived phytoestrogenic extract (HEPE) developed for prevention of steroid-associated ON using an established rabbit model. The underlying mechanisms of HEPE for prevention of steroid-associated ON were found to be associated with inhibition of both intravascular thrombosis and extravascular bone marrow lipid deposition, the two known mechanistic pathways in pathogenesis of ON. Our experimental results provide for potential clinical trials or applications of HEPE in the prevention of ON among hig-hrisk patients undergoing steroid treatment.

Multiple bioimaging modalities in evaluation of an experimental osteonecrosis induced by a combination of lipopolysaccharide and methylprednisolone

Aims:

The present study employed both static and dynamic imaging modalities to study both intra- and extravascular events attributing to steroid-associated osteonecrosis (ON) using an experimental protocol with a single low-dose lipopolysaccharide (LPS) injection and subsequently three injections of high-dose methylprednisolone (MPS).

Methods:

Fourteen 28-week-old male New Zealand white rabbits received one intravenous injection of LPS (10 μg/kg). 24 h later, three injections of 20 mg/kg of MPS were given intramuscularly at a time interval of 24 h. Additional 6 rabbits were used as controls. Dynamic MRI was performed on bilateral femora for local intraosseous perfusion before and after LPS injection. Blood samples were collected for hematological examinations before and after LPS injection. Bilateral femora were dissected and decalcified for microCT-based microangiography. ON lesion, intravascular thrombus and extravascular marrow fat cell size were examined histopathologically.

Results:

Intravascular thrombus was observed in all ON rabbits. Extravascular marrow fat cell size was significantly increased in ON rabbits than that of the controls (P < 0.05). Compared to baseline, a significant decrease in ratio of tissue-type plasminogen activator/plasminogen activator inhibitor 1, activated partial thromboplatin time and a significant increase in ratio of low-density lipoprotein/high-density lipoprotein were only found in ON rabbits (P < 0.05). Dynamic MRI showed a significant decrease in the perfusion index ‘maximum enhancement’ in the ON rabbits (P < 0.05), and microCT-based microangiography showed blocked stem vessels in ON samples. Overall, 93% of the rabbits (13/14) developed ON, and no rabbits died throughout the experiment period.

Conclusion:

Both intra- and extravascular events were found attributing to the steroid-associated ON based on our experimental protocol with a single low-dose LPS injection and subsequent three injections of high-dose MPS. Both high ON incidence and no mortality in rabbits treated with this inductive protocol suggested its effectiveness for future studies on evaluation of therapeutic efficacy of interventions developed for prevention of steroid-associated ON.

[Bilateral femoral cephalic osteonecrosis in a human immunodeficiency virus-infected child taking HAART]

Musculoskeletal complications are uncommon in HIV-infected patients. In adults, one manifestation is osteonecrosis which can be associated with risk factors such as alcohol consumption, smoking or use of corticosteroids. Such risk factors are rare in children. Over the last decade musculoskeletal complications have been observed in patients with advanced-stage disease or whose immune system has been reconstituted with highly active antiretroviral therapy (HAART). This complication has been reported in adults but to date not in children. We present the case of a 5-year-old child with AIDS (C stage 3) who developed osteonecrosis related to the advanced stage of the illness and to HAART. No risk factors were found.

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.

[Pain management in non-juvenile, aseptic osteonecrosis]

BACKGROUND

Adult aseptic osteonecrosis (ON) represents a clinical picture with unexplained etiology. Since curative treatment of this disease often succeeds only in the early stage, pain therapy plays an important role in the treatment process.

METHOD

We compared established and novel treatment options for ON as well as our own results after i.v. administration of the prostacyclin analogue iloprost with corresponding studies in the literature.

RESULTS

In addition to treatment with nonsteroidal antirheumatic agents and opioids, surgical "core decompression," vasoactive medications, and hyperbaric oxygenation are effective. Treatment with iloprost for 5 days resulted in highly significant pain reduction.

CONCLUSION

Symptomatic treatment is indicated in all stages of ON and curative treatment in stage I and early stage II. In cases of disease progression in the large joints, early endoprosthetic replacement is indicated to avoid secondary damage. In addition to employing vasoactive substances, a further curative treatment approach could be the use of mesenchymal stem cells.

Bone Disorders Associated with the Human Immunodeficiency Virus: Pathogenesis and Management

Bone disorders such as osteopenia, osteoporosis, and osteonecrosis have been reported in patients infected with the human immunodeficiency virus (HIV), but the etiology and mechanism of these disorders are unknown. The prevalence estimates vary widely among studies and may be influenced by the presence or absence of antiretroviral therapy and lipodystrophy, severity of HIV disease, and overlapping bone loss risk factors. Addressing potential underlying bone disease risk factors (e.g., smoking and alcohol intake), evaluating calcium and vitamin D intake, and performing dual x-ray absorptiometry in patients with HIV who have risks for bone disease are important strategies in preventing osteopenia and osteoporosis in HIV-infected patients. Management of osteopenia and osteoporosis is still being evaluated. Administration of bisphosphonates (e.g., alendronate), with calcium and vitamin D supplementation, may be reasonable in treating osteoporosis; however, surgical intervention is the only method for treating symptomatic osteonecrosis.

Principles of antiretroviral treatment of children and adolescents with human immunodeficiency virus infection

Human immunodeficiency virus (HIV) infection requires life-long therapy to attain durable suppression of HIV replication and prevent or reverse HIV-related symptoms or immune system dysfunction. Combination therapy with 3 or more antiretroviral medications is currently widely recommended for treatment of children and adolescents with HIV infection. While potent regimens can initially reduce virus load to below assay quantitation limits in the majority of persons with HIV infection, 30% to 80% of children will have regimen failure and return of detectable plasma virus within 1 year. Adherence to therapy is critical to regimen success. Optimal treatment requires careful use of potent combinations of drugs, with attention to adherence, palatability, toxicity, and pharmacokinetics. Practitioners with experience caring for children and adolescents with HIV infection should be involved.

Interactions between antiretroviral drugs and drugs used for the therapy of the metabolic complications encountered during HIV infection

Treatment of HIV infection with potent combination antiretroviral therapy has resulted in major improvement in overall survival, immune function and the incidence of opportunistic infections. However, HIV infection and treatment has been associated with the development of metabolic complications, including hyperlipidaemia, diabetes mellitus, hypertension, lipodystrophy and osteopenia. Safe pharmacological treatment of these complications requires an understanding of the drug-drug interactions between antiretroviral drugs and the drugs used in the treatment of metabolic complications. Since formal studies of most of these interactions have not been performed, predictions must be based on our understanding of the metabolism of these agents. All HIV protease inhibitors are metabolised by and inhibit cytochrome P450 (CYP) 3A4. Ritonavir is the most potent inhibitor of CYP3A4. Ritonavir and nelfinavir also induce a host of CYP isoforms as well as some conjugating enzymes. The non-nucleoside reverse transcriptase inhibitor delavirdine potently inhibits CYP3A4, whereas nevirapine and efavirenz are inducers of CYP3A4. Drug interaction studies have been performed with HIV protease inhibitors and HMG-CoA reductase inhibitors. Coadministration of ritonavir plus saquinavir to HIV-seronegative volunteers resulted in increased exposure to simvastatin acid by 3059%. Atorvastatin exposure increased by 347%, but exposure to active atorvastatin increased by only 79%. Conversely, pravastatin exposure decreased by 50%. Similar results have been obtained with combinations of simvastatin and atorvastatin with other HIV protease inhibitors. Thus, the lactone prodrugs simvastatin and lovastatin should not be used with HIV protease inhibitors. Atorvastatin may be used with caution. Although there are no formal studies available, calcium channel antagonists and repaglinide may have significant interactions and toxicity when used with HIV protease inhibitors because of their metabolism by CYP3A4. Sulfonylurea drugs utilise mainly CYP2C9 for metabolism, and this isoenzyme may be induced by ritonavir and nelfinavir with a resulting decrease in efficacy of the sulfonylurea. Losartan may have increased effect when coadministered with ritonavir and nelfinavir because of the induction of CYP2C9 and the expected increase in formation of the active metabolite, E-3174. Overall, well-designed drug-drug interaction studies at steady state are needed to determine whether antiretroviral drugs may be safely coadministered with many of the drugs used in the treatment of the metabolic complications of HIV infection.

Antiphospholipid antibodies and infections

Many infections have been found to be associated with antiphospholipid antibodies (aPL), although a pathogenic role for these antibodies has not usually been obvious except in a few isolated cases. Two types of aPL have been referred to as "autoimmune" and "infectious" types. This distinction, however, has subsequently been found not to be absolute.

A study of the immunology, virology, and safety of prednisone in HIV-1-infected subjects with CD4 cell counts of 200 to 700 mm(-3)

Adult Clinical Trials Group Study 349 examined the immunology, virology, and safety of 40 mg/d prednisone as an adjunct to antiretroviral therapy in 24 HIV-infected subjects with >200 CD4+ T cells/mm in a randomized placebo-controlled trial. After 8 weeks, median lymphocyte and CD4+ cell numbers increased >40% above baseline values (p =.08). No effect was observed on markers of cell activation or apoptosis, although the proportion of CD28+ CD8+ T cells increased (p =.006). Prednisone inhibited monocyte TNFalpha production without affecting T-cell responses to antigens or mitogens. Two subjects assigned to prednisone were subsequently found to have asymptomatic osteonecrosis of the hip. Many questions remain regarding the role of activation-induced sequestration and apoptosis as causes of progressive CD4+ T-cell loss in AIDS. The potential role of corticosteroids as tools to examine this question will be limited by concerns regarding their toxicity; however, further studies of other agents to limit cellular activation in AIDS are warranted.

Management of metabolic complications associated with antiretroviral therapy for HIV-1 infection: recommendations of an International AIDS Society-USA panel

OBJECTIVE

Alterations in glucose and lipid metabolism, lactic acidemia, bone disorders, and abnormal body fat distribution have been recognized recently as frequent complications associated with HIV-1 infection and potent antiretroviral therapy, but limited data are available regarding the appropriate management of these disorders. These recommendations were developed to guide physicians actively involved in HIV care in the management of metabolic complications that occur primarily within the context of potent antiretroviral therapy.

PARTICIPANTS

A 12-member panel representing international expertise in HIV-1 patient care, antiretroviral therapy, and endocrine and metabolic disorders was selected in the spring of 2000 by the International AIDS Society-USA, a not-for-profit physician education organization. Panel members met in closed meetings beginning in May 2000. All work was funded by the International AIDS Society-USA; the panel members are not compensated for their participation.

EVIDENCE

The panel reviewed published results of clinical, epidemiologic, and basic science studies and data and abstracts presented at research conferences, primarily from 1997 to 2002. The panel also considered studies of the pathophysiology and treatment of similar metabolic abnormalities in noninfected persons. Emphasis was placed on results from prospective, randomized, controlled clinical trials when available.

PROCESS

For each metabolic complication, 1 or more member(s) reviewed and presented all available evidence to the panel, and then wrote a summary of the evidence and preliminary recommendations. Final recommendations were determined by full group consensus. The summaries were combined into a single working document and all panel members edited and approved all subsequent drafts.

CONCLUSIONS

Carefully controlled studies to determine the incidence, etiology, risk factors, and most appropriate treatments for metabolic complications in HIV-1 infection are urgently needed. In the absence of these data, and to prevent acute illness and mitigate long-term risks, the panel recommends routine assessment and monitoring of glucose and lipid levels and assessment and monitoring of lactic acidemia and bone abnormalities if clinical signs or symptoms are detected. With the exception of body fat distribution abnormalities, specific treatments for these complications are also recommended. Successful long-term antiretroviral therapy will require diligent monitoring and preemptive treatment of metabolic complications to optimize the risk-benefit ratio of antiretroviral therapies.

Long-term exposure to lifelong therapies

Three categories of highly active antiretroviral therapy (HAART)-associated major toxic effects have been identified: nucleoside-related toxic effects (e.g., neuropathy, myopathy, pancreatitis, hepatic steatosis, lactic acidosis, and possibly lipoatrophy), metabolic complications (e.g., fat redistribution, insulin resistance, and hyperlipidemia), and bone disease (e.g., osteopenia and/or osteoporosis). The toxic effects caused by nucleosides are hypothesized to be a result of mitochondrial injury and include myopathy, pancreatitis, liver failure, and lactic acidosis. Alterations in lactic acid metabolism range from common instances of asymptomatic lactic acidemia to rare occurrences of life-threatening lactic acidosis with hepatic steatosis. A metabolic syndrome consisting of lipodystrophy (i.e., fat redistribution), hyperlipidemia and insulin resistance has been observed, particularly with protease inhibitor treatment. Some additive interaction between protease inhibitors and nucleosides has also been described. The potential relationship of these metabolic abnormalities to increased risk of cardiovascular disease and diabetes has broad implications on long-term patient management. Lipodystrophy associated with HAART is generally accompanied by potentially serious abnormalities, including dyslipidemia (i.e., hypercholesterolemia and hypertriglyceridemia) and altered glucose metabolism (i.e., insulin resistance). Regimens of HAART may have adverse effects on bone metabolism, as indicated by emerging reports of osteopenia, osteoporosis, and avascular necrosis.