BONE REMODELING IN HUMAN IMMUNODEFICIENCY VIRUS-1-INFECTED PATIENTS -A HISTOMORPHOMETRIC STUDY

The aim of this study was to identify and describe possible alteration s of bone histomorphometry in patients with human immunodeficiency vir us (HIV-1) infection and to assess the relation between these alterati ons and disease severity, Forty-four HIV-1-infected patients seen succ essively at our hospital were evaluated for the study, In an attempt t o avoid confounding factors as far as possible, we excluded patients w ho fulfilled any of the following criteria: age less than 18 or greate r than 40 years; recent history of extended bed rest; previous diagnos is of metabolic bone disease, renal insufficiency, or hepatic failure; clinical or echographic signs of liver cirrhosis; diabetes mellitus o r previous diagnosis of other endocrine diseases; drug therapy that co uld act on bone metabolism; and/or moderate to severe nutritional alte ration, Twenty-two patients (13 men, 9 women; age: 27.9 +/- 4.1 years, mean +/- standard deviation) were included in the study, Plasma and u rine biochemistry and calcium-regulating hormones were determined, Bon e mineral content was measured on vertebrae L2 to L4 and an the neck a nd intertrochanteric areas of the femur by dual-photon absorptiometry, A transiliac bone biopsy was performed after double-tetracycline labe lling, with histomorphometric study of undecalcified bone, Serum osteo calcin was found to be lower in patients who, according to the Centers for Disease Control (CDC) classification, had greater disease severit y, and showed a positive correlation with the number of CD4(+) T lymph ocytes, No alterations in bone densitometry were observed, Several his tomorphometric parameters of bone formation and turnover and the numbe r of osteoclasts were significantly lower in the patients than in the healthy controls (surface-based bone formation rate: 0.01 +/- 0.01 mu m(3)/mu m(2)/day versus 0.04 +/- 0.02 mu m(3)/mu m(2)/day, p = 0.05; a ctivation frequency: 0.02 +/- 0.03 year(-1) versus 0.25 +/- 0.13 year( -1), p = 0.004; osteoclast index: 0.02 +/- 0.08 mm(-2) versus 0.03 +/- 0.04 mm(-2), p = 0.005), Several parameters of formation, such as sur face-based bone formation rate, or of turnover, such as activation fre quency, were lower in patients with greater disease severity according to the CDC classification and presented a positive correlation with t he number of CD4(+) T lymphocytes, No biochemical parameter of mineral metabolism or hormones, except osteocalcin, showed a correlation with disease severity, We conclude that HIV-1-infected patients in our ser ies presented a notable decrease in bone formation and turnover, These changes appeared to be more marked in patients with more severe disea se.