Letters to the Editor
Table 2. Recovery of 5 Patients from Tenofovir-Related Nephrotoxicity Age (years)/ Sex
Months after Discontinuation of Tenofovir
Base/Trough Serum Creatinine (mg/dL)
53/Male
3
1.1/1.2
46/Male
2
1.2/1.3
38/Male
1
1.1/1.2
45/Male
3
1.3/1.4
34/Male
3
1.0/1.1
Urinalysis/ Sediment
Protein/ Creatinine ratio
K⫹ (mg/dL)
HCO3 (mEq/L)
Phos (mg/dL)
Glu (mg/dL)
0.3
3.8
22
2.9
89
0.6
4.3
24
3.6
98
0.12
4.0
23
3.8
90
0.85
4.7
22
3.9
89
0.18
4.1
22
3.6
96
1.018 trace protein (⫺) glucose 1.020 1⫹ protein (⫺) glucose 1.018 (⫺) protein (⫺) glucose 1.015 1⫹ protein (⫺) glucose 1.020 (⫺) protein (⫺) glucose
Glu ⫽ serum glucose; HCO3 ⫽ serum bicarbonate; K⫹ ⫽ serum potassium; Phos ⫽ serum phosphorus.
tiation of tenofovir. Fortunately, no long-term renal impairment has been described as a consequence of tenofovir-related nephrotoxicity. Brian S. Rifkin, MD Mark A. Perazella, MD Yale University School of Medicine New Haven, Connecticut 1. Coca S, Perazella MA. Rapid communication: acute renal failure associated with tenofovir: evidence of drug-induced nephrotoxicity. Am J Med Sci. 2002;324:342–344. 2. Meier P, Dautheville-Guibal S, Ronco PM, Rossert J. Cidofovir induced end-stage renal failure. Nephrol Dial Transplant. 2002;17: 148 –149. 3. Tanji N, Tanji K, Kambham N, et al. Adefovir nephrotoxicity: possible role for mitochondrial DNA depletion. Hum Pathol. 2001;32:734 –740. 4. Ho ES, Lin DC, Mendel DB, Cihlar T. Cytotoxicity of antiretroviral nucleotide adenovir and cidofovir is induced by the expression of human renal organic anion transporter 1. J Am Soc Nephrol. 2000;11:383–393. 5. U.S. Food and Drug Administration. FDA report: background package for NDA 21-356: VIREAD (tenofovir disoproxil fumarate). 2001. 6. Karras A, Lafauri M, Furco A, et al. Tenofovir-related nephrotoxicity in human immunodeficiency virus infected patients: three cases of renal failure, Fanconi syndrome, and nephrogenic diabetes insipidus. Clin Infect Dis. 2003;36:1070 –1073. 7. Schaaf B, Aries SP, Kramme E, et al. Acute renal failure associated with tenofovir treatment 284
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in a patient with acquired immunodeficiency syndrome. Clin Infect Dis. 2003;37:41– 43. 8. Verhelst D, Monge M, Meynard JL, et al. Fanconi syndrome and renal failure induced by tenofovir: a first case report. Am J Kidney Dis. 2002;40:1331–1333.
SPONTANEOUS SPONDYLODISCITIS CAUSED BY BACTEROIDES UNIFORMIS To the Editor: Most cases of infectious discitis in adults have occurred following spinal surgical procedures. Disc infection that occurs as a spontaneous process is considerably less common (1). Spondylodiscitis caused by anaerobic bacteria is exceptional (2). We report an immunocompetent adult with spontaneous lumbar spondylodiscitis due to Bacteroides uniformis. A 78-year-old man without remarkable medical history was admitted with a 2-week syndrome of fatigue, anorexia, malaise, fever, chills, and low back pain without a radicular component. Physical examination revealed fever of 37.6°C, moderate ten-
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derness to palpation over L4 –L5, and decreased range of motion in the lumbar spine. Motor examination, deep-tendon reflexes, and sensation were normal. Laboratory data showed an erythrocyte sedimentation rate of 63 mm/h, C-reactive protein level of 5.16 mg/dL, white blood cell count of 12,400 ⫻ 103/L with 78% polymorphonucleocytes, 4 percent bands. Results of urine culture were negative. Serologic tests for Brucella, Salmonella, Francisella, Treponema, Legionella, Mycoplasma, Chlamydia, Leptospira and Rickettsia spp. were negative. Magnetic resonance imaging (MRI) showed findings suggestive of spondylodiscitis (Figure). The search for an infectious entrance door was negative. Blood cultures were positive (3/3) for B. uniformis. The patient was treated with intravenous imipenem and metronidazole for 4 weeks, and amoxicillin-clavulanic acid (875/125) for 2 more weeks. Complete recovery was achieved 6 months after discharge. Patients with spontaneous spondylodiscitis have demonstrated a wide variety of aerobic gram-positive and gram-negative organisms (1). Spon-
Letters to the Editor
Figure. Magnetic resonance imaging findings. Narrowing of the disc space at L4 –L5 affecting the bone marrow of vertebral bodies with destruction of the anterosuperior edge (panels A and B, arrows and asterisk). Masses in soft tissue of both sides without compressive effect (panel C, star).
dylodiscitis due to anaerobic organisms is exceptional and could occur uncommonly in an immunocompetent patient (2). Little attention has been paid to the potential role of anaerobes (Bacteroides, Fusobacteria, and anaerobic cocci) in bone infection (3). The anaerobic gram-negative bacteria from Bacteroides are among the most important components of human flora, abounding in the mouth, gastrointestinal tract, and vagina, where they could produce a wide variety of infections with a tendency to abscess (4). On 911 strains isolated by Rodloff et al (5), bone constituted only 0.1% of isolates. The usual isolates from Bacteroides group causing spondylodiscitis are B. fragilis and B. melaninogenicus (2). Bacteroides uniformis is the least common
species isolated from clinical specimens (5,6). The most sensitive and specific imaging modality for diagnosing infectious discitis is MRI that identifies the lesion and changes consistent with discitis. Metronidazole, imipenem, and penicillins plus clavulanic acid remain very active against Bacteroides spp. The clinical presentation, laboratory data, and imaging findings in this case were similar to usual spondylodiscitis. We could not find an infectious entrance route. The patient did not have an immunosupressive state. Bacteroides uniformis had an excellent response to antibiotic therapy. In conclusion, we must keep in mind that other, unusual infectious organisms could cause spondylodiscitis. Blood and disc culture will allow August 15, 2004
the identification of the causal organism and so prevent the patient from receiving inadequate antimicrobial therapy (6). Enrique Antón, MD, PhD Conchi Fernández, MD Department of Internal Medicine Hospital of Zumárraga Guipúzcoa, Spain Jose Manuel Barragán, MD Department of Internal Medicine Hospital Nuestra Señora de Sonsoles Avila, Spain 1. Honan M, White W, Eisenberg G. Spontaneous infectious discitis in adults. Am J Med. 1996;100:85– 89. 2. Surbled M, Perrier C, Rabouille Y, et al. Spondylodiscite á Bacteroides melaninogenicus. La Presse Medicale. 1992;21:1870 –1871.
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Letters to the Editor 3. Lewis RP, Sutter VL, Finegold SM. Bone infections involving anaerobic bacteria. Medicine. 1978;57:279 –305. 4. Mader JT, Calhoun J. Osteomyelitis. In: Mandell GL, Bennett JE, Dolin R, eds. Mandell, Douglas and Bennett. Principles and
Practice of Infectious Diseases. 5th ed. Philadelphia: Churchill Livingstone, 2000: 1182–1195. 5. Rodloff AC, Werner H, Kresken M, et al. German multicentre study on the in vitro susceptibility of Bacteroides species. The
German Bacteroides Study Group. Eur J Clin Microbiol Infect Dis. 1990; 11:1074 –1080. 6. Zar F, Bond E. Infection with ClindamycinResistant Bacteroides uniformis. Chemotherapy. 1985;31:29 –33.
ERRATUM Ong MK and Glantz SA. Cardiovascular Health and Economic Effects of Smoke-Free Workplaces. Am J Med. 2004;117:32-38 On page 32, second column of the Abstract, the data for listed savings in direct medical costs in 1 year and at steady state are incorrect. The following text should replace the first two complete sentences: In 1 year, making all workplaces smoke free would prevent about 1500 myocardial infarctions and 350 strokes, and result in nearly $60 million in savings in direct medical costs. At steady state, 6250 myocardial infarctions and 1270 strokes would be prevented, and $279 million would be saved in direct medical costs annually. On page 36, second column, first paragraph, total averted costs within the first year should not include costs from prevented strokes. The following text should replace the first sentence: The total averted costs within the first year would include $48.6 million from prevented myocardial infarctions, of which $28.6 million (59%) would be attributable to prevented myocardial infarctions among former passive smokers (Table 4).
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