Nontuberculous mycobacterial infections in hematopoietic stem cell transplant recipients: Characteristics of respiratory and catheter-related infections

Abstract

Over a 20-year period, 40 nontuberculous mycobacteria (NTM) were isolated from 6259 hematopoietic stem cell transplant (HSCT) recipients (0.64%), of which 28 were considered to have probable or definite infection (0.44%). Only 3 of 15 lower respiratory isolates obtained by bronchoalveolar lavage (BAL) and/or biopsy; (Mycobacterium avium complex [n = 2] and M. gordonae [n = 1]) caused definite or probable lower respiratory tract disease, whereas 12 of 15 were considered to cause possible lower respiratory tract disease according to Centers for Disease Control and Prevention definitions. The median time to diagnosis was 251 days following HSCT. All 3 patients with definite NTM disease were successfully treated with 3 antimicrobials for several months. Twenty-three patients had catheter-related infections, including exit site infection (n = 5), tunnel infection (n = 7), and catheter-related bacteremia (n = 11). All were caused by rapidly growing mycobacteria. The median time to diagnosis was 61 days following HSCT. All patients with catheter-related infections were successfully treated with an average of 2 antibiotics for a median of 3 weeks for exit site infection and 6 weeks for tunnel infection and catheter-related bacteremia. Soft tissue debridement was performed in all cases with tunnel infection. The catheter was removed in 21 of 23 patients with catheter-related infections. Two additional patients were diagnosed, one with lymphadenitis and one with skin lesion, due to NTM. In conclusion, NTM infections are infrequent in HSCT recipients and carry a good clinical prognosis. In the majority of lower NTM respiratory isolates obtained by BAL, a pathogenic role could not be established. However, lower respiratory tract disease can occur late after HSCT and should be considered if patients fail to respond to the treatment of concomitant infections or if evidence of tissue infection or concomitant bacteremia is present. Therapy should be performed with 2 to 3 antimicrobials, guided by antimicrobial susceptibilities, with additional surgical debridement in patients with tunnel infection.

High rates of infection and colonization by nontuberculous mycobacteria after allogeneic hematopoietic stem cell transplantation

“…21,24 Despite their pathogenicity among a wide variety of hosts, NTM are uncommon pathogens in alloSCT recipients according to published reports. 8,9,12,15,25 Table 2 includes a comparison of the patients reported here and those from other series. The rates of positive cultures for NTM and NTM infection were 5-to 20-fold higher at our institution than at other centers.…”

“…CDC and American Thoracic Society criteria ( Figure 1) were used to define NTM infection. 9,21 Mycobacteria specimens were stained with the auramine acid-fast stain and cultured on Middlebrook 7H11 agar. In addition to conventional incubation, all mycobacteria specimens were evaluated for M. haemophilum using X-factor strips (Becton Dickinson Microbiology Systems) and incubated at 301C in a 10% CO 2 atmosphere for 6 weeks.…”

“…Both Mycobacterium tuberculosis and nontuberculous mycobacteria (NTM) are well-described pathogens in alloSCT recipients. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] However, distinguishing infection from colonization by NTM such as Mycobacterium avium complex (MAC) can be difficult, as infection by organisms other than NTM and noninfectious conditions such as graft-versus-host disease (GvHD) can mimic NTM infection in alloSCT recipients. Formal diagnostic criteria for NTM infection ( Figure 1) have been established by the Centers for Disease Control and Prevention (CDC) and the American Thoracic Society but remain controversial.…”

“…Formal diagnostic criteria for NTM infection ( Figure 1) have been established by the Centers for Disease Control and Prevention (CDC) and the American Thoracic Society but remain controversial. 9,21 Two comprehensive reviews of NTM infection among alloSCT recipients have been published, 9,12 both from centers that primarily perform conventional (ie, T-cell replete) transplants. In these reviews, NTM infection was rare, occurring in only 0.37 and 0.40% of patients.…”

Non-Tuberculous Mycobacterial Infection Localized in Small Intestine Developing after Allogeneic Bone Marrow Transplantation

“…An increased incidence of NTM infection has been reported among allogeneic HSCT recipients in recent years, ranging from 0.4% to 9.7% of cases (3)(4)(5)(6)(7). However, intestinal NTM infection is quite rare, and there has been only one other reported case after allogeneic HSCT (5) T a b l e 1 .…”