Table 1.
Summary of MAC Osteomyelitis Cases, Organized by Site of Infection (Vertebral vs Nonvertebral)
| Vertebral Cases | Age/Sex | CD4 Nadir (cells/mm3) | CD4 at Pres (cells/mm3) | Osteomyelitis Site | Time From ART Start to Presa | MAC Prophylaxisb | AFB Blood Culture | Surgical Debridement? | MAC Therapyc |
|---|---|---|---|---|---|---|---|---|---|
| Case 1 | 50/M | 14 | 414 | L1–L2 | 18 mo | None | Not done | Yes | Clarithro, ethambutol, rifabutin; amikacin later added |
| Case 2 | 52/M | 40 | 250 | L1–L4 | 9 mo | Azithro stopped 4 mo before pres | Negative | No | Azithro, ethambutol, cipro; amikacin and rifabutin later added |
| Matt 2013 et al [15]d | 50/F | 24 | 68 | L1 | 3 mo | Azithro started 5 wk before pres | Negative 4 mo before pres | Yes | Isoniazid, ethambutol, rifampin; cipro also for first 6 weeks |
| Corrales-Medina 2006 et al [18] | 35/M | 24 | 320 | L1–L3 | 12 mo | NR | NRe | CT-guided drainage | Clarithro, ethambutol, rifabutin, isoniazid, pyrazinamide; dexamethasone later added |
| Phillips 2005 et al [22]f | 37/M | 60 | 180 | T10 | 27 mo | NR | NR | CT-guided drainage | Clarithro, ethambutol |
| Aberg 2002 et al [7] #1g | 49/M | 16 | 465 | T9–T10 | 13 mo | Stopped 15 mo before pres | Negative | Yes | Clarithro, ethambutol, rifabutin, cipro |
| Aberg 2002 et al [7] #2 | 49/M | 23 | 118 | T6–T7 | NR | Stopped 3 mo before pres | NR | Yes | Clarithromycin and ethambutol initially; later changed to azithro and cipro |
| Fraser 2002 et al [13] | 56/M | 24 | 27 | T9–T11 | 15 mo | Azithro | Negative | Yes | Clarithro, ethambutol, rifabutin |
| Erard 1999 et al [8] | 36/F | 44 | 423 | T8–T10 | 9 mo | None | Negative | Yes | Clarithro, ethambutol, rifabutin |
| Libraty 1998 et al [21] | 30/M | 55 | 251 | T5–T6, T10–T11 | 15 mo | None | NR | Yes | NR |
| Nonvertebral Cases | Age/Sex | CD4 Nadir (cells/mm3) | CD4 at Pres (cells/mm3) | Site | Time to Presa | MAC prophylaxisb | AFB blood culture | Surgical debride-ment? | MAC therapyc |
| Kadzielski 2009 et al [16]h | 51/F | 20 | 34 | Tibia | 2 mo | Azithromycin | Negative | Yes | Clarithro, ethambutol, rifabutin, pyrazinamide and isoniazid initially; later narrowed to clarithro, ethambutol, rifabutin |
| Kahlon 2008 et al [14]i | 58/M | 15 | 47 | Calcaneus, cuboid | 5.5 mo | Azithro | Negative | Yes | Clarithro, ethambutol, rifabutin |
| Aberg 2002 et al [7] #3 | 40/M | 10 | 188 | 6th rib | >12 mo | Secondary prophylaxis stopped 16 mo prior | Positive 4 yr prior | No (lesion spontaneously drained through chest wall) | Clarithro, ethambutol, rifabutin, cipro initially; later narrowed to clarithro and ethambutol |
| Hospenthal 2001 et al [10] | 41/M | NR | 23 | Proximal tibia | NR | Rifabutin | Negative | Bone biopsy only | Clarithro, ethambutol |
| MGH case records 2000 [9] | 49/M | NR | 81 | Proximal tibia | 3 yr | None | NRe | No | NR |
| Sheppard 1997 et al [19] | 46/M | 8 | 53j | Tibial plateau | 11 mo | None | Negative | Yes | Clarithro, ethambutol, rifabutin |
| Valdez 1997 et al [23]k | 32/F | NR | 450 | Ileum | Not on ART | None | Negative | Yes | Initially rifampin, isoniazid, pyrazinamide, ethambutol, and amikacin; later narrowed to clarithro, ethambutol, and cipro |
| Weingardt 1996 et al [24] | 51/M | NR | 13 | Distal femur, proximal tibia | NR | NR | NR | CT-guided bone biopsy | NR |
| Blumenthal 1990 et al [20] | 30/M | NR | NR | Wrists, ankle | Not on ART | NR | Positive | No | Ansamycin, cycloserine, clofazamine, ethionamide |
Abbreviations: AFB, acid-fast bacilli; ART, antiretroviral therapy; azithro, azithromycin; cipro, ciprofloxacin; clarithro, clarithromycin; CT, computed tomography; Dx, diagnosis; L, lumbar vertebra; MAC, Mycobacterium avium complex; MGH, Massachusetts General Hospital; MTB, Mycobacterium tuberculosis; NR, not reported; pres, presentation; RIPE, rifampin, isoniazid, pyrazinamide, and ethambutol; T, thoracic vertebra.
a Estimated time to presentation of illness (MAC osteomyelitis) from start or restart of antiretroviral therapy (if multiple prior regimens, time from start of most recent regimen used).
b Prophylaxis being prescribed at the time of MAC diagnosis.
c Several patients initially started 4-drug therapy for presumed MTB before changing to MAC-targeted therapy; in these cases, only MAC-targeted therapy is listed (secondary MAC prophylaxis not included).
d Also had epidural abscess and surgical cultures also grew Staphylococcus epidermidis and Streptococcus viridans.
e Report states that blood cultures were negative but does not specify whether this was bacterial or mycobacterial or both.
f Presented 31 months after ART start with T10 pathological fracture and posterior mediastinal mass; treated as MTB for 12 months based on granulomas and AFB smear (no culture done); infection relapsed 27 months after ART restart, at which point MAC identified (information for relapsed infection included for this analysis because cause of initial infection not confirmed as MTB vs MAC). Developed epidural abscess after initiation of RIPE for MTB and required 2nd surgical drainage before MAC diagnosis and therapy.
g Also history of prior T6–T7 decompression for osteomyelitis 19 months before pres and T6 aspiration 17 months before pres with negative histopathology and cultures both times; time since initial ART was 30 months, although time since most recent ART regimen not reported.
h Presented 2 months earlier, at time of HIV/AIDS diagnosis, with CD4 20 and imaging evidence of tibial osteomyelitis (MAC not identified at that time); MAC identified after patient presented with recurrent symptoms after 2 months on ART so information for time of MAC identification used for this analysis.
i On prednisone for rheumatoid arthritis.
j CD4 count at presentation not reported; CD4 count 2 months before presentation was 8 cells/mm3 and 2 months after presentation was 98 cells/mm3, so 53 cells/mm3 represents the mean of these 2 values and is used as an estimate of the CD4 count at presentation.
k Prior corticosteroid use for sarcoidosis.