Chest
Volume 102, Issue 1, July 1992, Pages 70-75
Journal home page for Chest

Nontuberculous Mycobacteria in Adult Patients with Cystic Fibrosis

https://doi.org/10.1378/chest.102.1.70Get rights and content

Because patients with cystic fibrosis (CF) may be predisposed to airway infections with unusual microorganisms, we screened the sputum of adult CF patients for mycobacterial organisms. Acid-fast bacilli (AFB) smears and mycobacterial culture were performed on 297 sputum specimens from 87 patients. Cultures for mycobacteria were frequently overgrown with other bacteria; 22.6 percent of cultures were contaminated. Despite this limitation of mycobacterial culture, 17 patients had at least one positive culture for a Mycobacterium other than tuberculosis (MOTT). Eleven patients were positive for Mycobacterium avium-intracellulare (MAI), two for MAI and M chelonei, three for M chelonei, and one for M fortuitum. None was positive for M tuberculosis. Patients with CF with MOTT were similar to patients with CF without MOTT; only a slightly different (older) age distribution was recognized. The clinical significance of MOTT was difficult to determine in any individual patient, but patients with positive AFB smears appeared more likely to suffer pathogenic effects. We conclude that MOTT is frequently recovered from adult CF patients in the southeastern United States. A specific risk factor for colonization and/or pathogenic infection in Ais patient group was not evident. The general prevalence and clinical pathogenesis in CF patients in the United States remains to be determined. (Cheat 1992; 102:70–75)

Section snippets

Patients

Ninety-one patients have been seen on a regular basis in the adult CF clinic at the University of North Carolina Hospitals since 1981 and 87 (96 percent) had at least one sputum specimen submitted for AFB smear and culture. Most of the regularly followed-up patients are young adults (mean age, 28.3 years; range, 18 to 64 years); eight of these patients are now dead.

We reviewed the medical records of all adult CF patients with particular attention to the diagnosis of CF and clinical status at

RESULTS

Eighty-seven of the patients followed up in the adult CF clinic between 1981 and late 1990 had at least one sputum specimen submitted for AFB smear and culture (see Table 1). A total of 297 respiratory tract specimens for AFB cultures were submitted, and 17 patients (20 percent) had at least one culture positive for MOTT. An AFB prevalence of 20 percent in this patient population may be an underestimation because bacterial contamination of AFB cultures was a problem in determining AFB status.

CASE REPORT

The case report describes the clinical course of the initial patient (case 1; Table 2) with pathogenic infection with MAI. She is a resident physician who had childhood wheezing and recurrent bronchitis. In 1982, at age 20 years, she had elevated sweat chloride values (>90 mEq/L). Pulmonary function tests showed moderate obstructive impairment (FEV1 = 63 percent predicted). Sputum AFB smear and cultures were negative. In 1986, the patient developed dyspnea on exertion, increased cough,

DISCUSSION

The prevalence of MOTT isolates in these adult CF patients is surprisingly high; 20 percent had at least one isolate of potentially pathogenic MOTT, while 7 percent had only contaminated cultures so that infection status could not be determined. Only two other studies, by Smith et al2 in London and Hjelte et al6 in Sweden, have screened large series of CF patients for mycobacteria; many of these patients were younger than age 18 years. Of 277 patients whose sputa were examined for AFB in these

ACKNOWLEDGMENTS

The authors thank Tom Boat, M.D., Gerald Fernald, M.D., John Jacoby, M.D., Marty Prince, M.D., Lynn Sobel, R.N., and the UNC Pulmonary Fellows for assistance in performing this study; and Jeffrey Glassroth, M.D., for a critical review of the manuscript. We also thank Karen Alston, Lisa Brown, and Leigh Noble for their assistance in preparing this manuscript.

REFERENCES (21)

  • EfthimiouJ et al.

    Fatal pulmonary infection with Mycobacterium fortuitum in cystic fibrosis

    Br J Dis Chest

    (1984)
  • BoxerbaumB.

    Isolation of rapidly growing mycobacteria in patients with cystic fibrosis

    J Pediatr

    (1980)
  • WoodRE et al.

    State of the art: cystic fibrosis

    Am Rev Respir Dis

    (1976)
  • SmithMJ et al.

    Mycobacterial isolations in young adults with cystic fibrosis

    Thorax

    (1984)
  • KinneyJS et al.

    Mycobacterium avium complex in a patient with cystic fibrosis: disease vs colonization

    Pediatr Infect Dis

    (1989)
  • HjelteL et al.

    Prospective study of mycobacterial infections in patients with cystic fibrosis

    Thorax

    (1990)
  • HighsmithWE et al.

    Frequency of Phe506 mutation and correlation with XV.2c/KM-19 haplotypes in an American population of cystic fibrosis patients: results of a collaborative study

    Clin Chem

    (1990)
  • SummersHM et al.

    Mycobacterium

  • DrakeTA et al.

    Rapid identification of Mycobacterium avium complex in culture using DNA probes

    J Clin Microbiol

    (1987)
  • Evaluation of impairment/disability secondary to respiratory disease

    Am Rev Respir Dis

    (1982)
There are more references available in the full text version of this article.

Cited by (0)

This work was supported in part by NIH grant HL34322; CRU grant RR00046; UNCCFRDP grant R015; and SCOR grant CR80739202.

Manuscript received August 22; revision accepted October 29.

View full text