Correlation of Quantitative Bone Marrow and Blood Cultures in AIDS Patients with DisseminatedMycobacterium aviumComplex Infection

Abstract

The relationship between Mycobacterium avium complex (MAC) infection of blood and bone marrow was studied in human immunodeficiency virus-infected patients before and during treatment. Quantitative cultures were obtained at baseline from 17 persons with newly detected MAC bacteremia. Serial blood cultures were obtained, and a second bone marrow sample was obtained at 4 or 8 weeks. At baseline, the median MAC load in bone marrow core samples was 3 log10 higher than in blood. Bone marrow MAC loads ranged widely (866-847,315 cfu/g), and no significant correlation was found between MAC load in blood and that in bone marrow core samples. MAC loads in bilateral bone marrow biopsy samples from 7 subjects were highly correlated. MAC loads declined in blood and bone marrow at similar rates during therapy, but blood was sterilized before bone marrow. Length of survival was inversely associated with initial bone marrow core MAC load but not with blood MAC load. Initiation of treatment when tissue MAC load is low may increase the likelihood of favorable clinical outcome.

A Randomized, Double-Blind Trial Comparing Azithromycin and Clarithromycin in the Treatment of Disseminated Mycobacterium avium Infection in Patients with Human Immunodeficiency Virus

“…The definition of relapse was similarly affected, and in sensitivity analyses performed on these data, when cultures with 1 cfu/mL were treated as sterile, relapse rates overall were reduced and relative differences in relapse rates between the azithromycin and the clarithromycin groups disappeared (data not shown). This observation underscores the difficulty in defining a sterilization end point that represents true clearance of bacterial burden, because a negative blood culture does not necessarily reflect sterility at all sites [20].…”

“…It has recently been observed that the addition of rifabutin to a combination of clarithromycin and ethambutol did not add significantly to efficacy [20]. However, as was suggested by the authors of that report [20], perhaps the addition of rifabutin to an azithromycin and ethambutol combination would provide an added measure of efficacy given the lower breakthrough rate of that combination in prophylaxis of MAC and the lack of pharmacokinetic interactions between the 2 drugs [22,23].…”

Impaired CD4-cell immune reconstitution upon HIV therapy in patients with toxoplasmic encephalitis compared to patients with pneumocystis pneumonia as AIDS indicating disease

“…A less probable reason for the observed difference would be a direct interaction of the opportunistic infection with the immune system, for example by suppressing myelopoiesis, as it has been shown for generalized infection with Mycobacterium avium complex (MAC) [25-27]. A similar myelosuppressive effect caused by Toxoplasma has been demonstrated in the acute infection in mice.…”

Killing ofMycobacterium aviumandMycobacterium tuberculosisby a Mycobacteriophage Delivered by a Nonvirulent Mycobacterium: A Model for Phage Therapy of Intracellular Bacterial Pathogens

“…7.8 ϫ 10 Figure 4 shows the effect of M. smegmatis-TM4 in macrophages infected with M. avium for 48 h prior to treatment. became available, killing of the bacteria in deep tissues (i.e., bone marrow) usually is not achieved [20]. In addition to the problem of M. avium and M. tuberculosis resistance to antibiotics, both bacteria are able to infect and grow within macrophages and monocytes, and in vivo undergo a latent or dormant phase of infection in the host [1].…”