1. Invasive mycoses in cystic fibrosis and lung transplant
Elio Castagnola
Infectious Diseases Unit
“G.Gaslini” Children Hospital
Genoa - Italy

2. Cystic fibrosis (CF)
An autosomal recessive disease that cause abnormalities of ion transport of epithelilal cells and presents as a multisystem disease
Chronic infections in the lungs are among the most preminent clinical manifestations and are related with the obstruction of respiratory ways by viscous secretions
Mucus hypoxia and stasis may contribute to the propensity for bacterial infections, mainly due to Sthaphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas maltopilia and Burkholderia cepacia.

4. Fungi in the respiratory tract of patients with CF
The defective mucociliary clearance is associated with local immunological disorders. Moreover, the prolonged antibacterial therapy and the use of corticosteroid treatments also facilitate fungal growth.
A. fumigatus, S. apiospermum and A. terreus for filamentous fungi and C. albicans for yeasts are the main fungal species associated with CF
A. flavus and A. nidulans may be isolated transiently from CF respiratory secretions, while others such as Exophiala dermatitidis and Scedosporium prolificans may chronically colonize the airways
Penicillium emersonii and Acrophialophora fusispora are encountered in humans almost exclusively in the context of CF
The clinical relevance of the fungal airway colonization is mainly unknown, but it would be not surprising the discover that filamentous fungi contribute to the local inflammatory response, and therefore to the progressive deterioration of the lung function.

5. Allergic Broncho Pulmonary Aspergillosis (ABPA)
ABPA is a long-term allergic response to Aspergillus, mainly observed in patients with severe, persistent asthma and in CF
In CF bacterial pneumonia and ABPA may present with similar clinical features, and their differential diagnosis could be very difficult, not forgetting that both conditions could be present simultaneously.
Therefore, specific criteria are used to establish the diagnosis of ABPA

6. Allergic Broncho Pulmonary Aspergillosis (ABPA)
Pathogenesis is very complex:
After colonization, Aspergillus germinates to form hyphe.
The response to these antigens is of the Th2 type, with release of cytokines IL-4, IL-5, and IL-13 (maybe driven also by peculiar HLA)
Recent studies suggest a pivotal role of chemokines (especially CCL17 and its receptor CCR4)
The inflammation in the bronchial submucosa leads to excessive mucin production, extravasation of eosinophils into the bronchial mucin, intermittent bronchial obstruction with atelectasis, and, over time, to bronchiectasis
The picture may become even worst if we consider that the brochial secretion in CF are particularly though and may represent a culture media for other pathogens (e.g. Pseudomonadaceae)
Allergic Broncho Pulmonary Aspergillosis (ABPA)
ABPA is a long-term allergic response to Aspergillus, mainly observed in patients with severe, persistent asthma and in CF
In patients with asthma clinical manifestations are episodic wheezing, expectoration of brown mucus plugs, low-grade fever, eosinophilia, and transient pulmonary infiltrates due to atelectasis. Central bronchiectasis occurs in some patients after several years of disease
In CF bacterial pneumonia and ABPA may present with similar clinical features, and their differential diagnosis could be very difficult, not forgetting that both conditions could be present simultaneously.
Therefore, specific criteria are used to establish the diagnosis of ABPA

7. Criteria for the diagnosis of ABPA
Using these criteria in CF patients the incidence of ABPA is approximately 7% (ranging 2%-15%), increasing after the 6th year of age
This is not surprising since colonization with Aspergillus has been shown to be age-related aslo in children with asthma
1999
Clin Infect Dis, 2003/2004
In these patients eosinophilia is not a useful diagnostic tool because the patients may have elevated peripheral blood eosinophils from other causes such as Pseudomonas aeruginosa infection.

8. In patients with asthma clinical manifestations are episodic wheezing, expectoration of brown mucus plugs, low-grade fever, eosinophilia, and transient pulmonary infiltrates due to atelectasis.
Central bronchiectasis occurs in some patients after several years of disease.
Without adequate treatment the evolution is toward progressive, irreversible lung damage, leading to pulmonary fibrosis

9. Therapy
Attenuation of inflammation and immunological activity: systemic steroids
Side effects tue to long term, high dose steroids
Attenuation of antigen burden from heavy colonization: itraconazole, some effect, but
Many drug interactions, long term suppression of adrenal glucocorticoid synthesis (associated with budesonide), liver toxicity

10. Other therapeutic options
Voriconazole: improvements in serological parameters (IgE) and decrease in steroids administration, some effect on pulmonary function, but not in all patients
Triazoles: many drug interaction
Probably necessary TDM
Nebulized liposomal amphotericin B+ nebulized budesonide
Use of anti IgE monoclonal antibodies (omalizumab)

11. Effect of A.fumigatus infections in CF without ABPA
Retrospective analysis on 230 patients
FEV(1) lower in chronically infected patients
Interactions between A.fumigatus and P.aeruginosa on lung function
Higher risk of exacerbation of pulmonary disease,
Respiratory deterioration not responding to antibacterials in patients colonized with A.fumigatus, in absence of criteria for diagnosis of ABPA: a new clinical syndrome in CF or the first stage of ABPA ?

12. Scedosporium... a new challenge?
Voriconazole should be the drug of choice, but the caveats regarding interactions and absence of kinetics data still remains...

13. Implanted CVC-related fungal infections
Type of CVC
Infections/ 100 CVC
Proportions of candidemias
Infections/ 1000 CVC days
Literature CF
(3 studies)
Totally
5-8
(95%CI )
8-10%
1.4%-4.6%
(95%CI )
Partially
21-37
47 (*)
6.6%
(**)
(*) 7 episodes in 1 patient!
(**) PIVADS in 1 study only, not stratified TIVADS/PIVADS
In patients with CF
disease severity
frequent antibiotic usage
corticosteroid therapy
diabetes mellitus
all have been associated with an increased risk of candidemia

14. Lung transplant becomes the only therapeutic option for end-stage lung disease in CF, but...
Type of transplant
(n of procedures) (Dummer, 2005)
infections per patient
invasive mycoses (%)
proportions of infectios (%)
most common site
kidney (64)
0.98 41
urinary tract
heart (119)
1.36 8 27
lung
heart-lung (31)
3.19 23 57
liver (101)
1.86 16
abdomen & biliary tract

15. Aspergillosis
Incidence 6-16% of transplant, 2.4% cumulative incidence at 1 year, late onset (> 3 months) infection is becoming more frequent and is associated with rejection (intensified immunosuppression) and retransplantation (Clin Chest Med 2009; 30: 307. Curr Infect Dis Rep 2009; 11: Pediatrics 2008; 121:1286)
Clinica features
Acute inflammatory pneumonia
Chronic necrotizing aspergillosis
Tracheobronchitis affecting the anastomotic site and causing dehiscence of the suture
Possibe dissemination
No distinctive radiological features

16. Pre transplant colonization
22-58% of FC, 28% of non-FC
In FC 25%-42% of colonized patients will develop invasive disease after LTx
In non fc 34% with IA
A.fuigatus the most frequently isolated
Risk of disease without prophylaxis 11 times higher than in non colonized, within 6 months from Tx
Colonization within 1 year after tx, 6 times higher risk of IA
No major role of azole prophylaxis

17. Post transplant aspergillosis in CF (Helmi et al, Chest 2003; 123: 800)
Fungal infection developed in 44% (14/32) of patients
tracheo-bronchial aspergillosis was observed in 9 (in 1 associated with pneumonia)
isolated pneumonia was observed in 5
survival was 21% (3/14)

18. Candida
Candida is frequently isolated from the respiratory tract; however, it rarely causes invasive pulmonary disease.
The risk of invasive candidiasis seems be associated with concomitant bacterial infections or multiple organ failure
Invasive infections due to Candida (Transplant Infect Dis 2009: 11:112; transplantation 2000; 70:112)
384 L/HLTx from 1980 to 2004, with a decreasing incidence in process of time
32 IFD (8%): manly tracheobronchitis (31%), including the anastomotic site, bloodstream (28%) and disseminated (13%) infections

19. Other mycoses
Pneumocystosis (Clin Infect Dis 2002; 34:1098; Clin Microbiol Rev 2004; 17:770)
Attack rate % without prophylaxis, 35% symptomatic, 4% severe infections
Between 3 and 6 months after Tx
Short prodromic period (< 5 days)
Cryptococcosis (Clin Infect dis 2009; 48:1566)
In LTx the incidence is increasing
Up tp 6% of patients treated with tacrolimus
Non-aspergillus filamentous fungi (J Heart Lung Transpant 2008; 27: 850):
Colonization in 14.5% of LTx, a median of 415 days from the procedure, mainly zygomycetes, 1 case of probable IFD

20. Indirect diagnosis Serum 1-3 bera-D-Glucan: no data
Serum Galactomannan: no data in a wide meta-anaysis (Clin Infect Dis 2006; 42:1417)
Only 1 study in LTx Cochrane Review 2009: high risk of false positive in the early days after LTx in FC (Am J Transplant 2004; 4:796)
Galactomannan in BAL fluid: Sensitivity 82%. Specificity 96%, (Clin Vacc immunol 2008; 15: 1760)

21. Drugs

22. Nebulized amphotericin B for prophylaxis (Int J Antimicrob Agents 2008; 32 (Suppl 2): s161
Nebulized lipid preparations of amphotericin B: greater deposition in the lungs and longer half-life (compared with deoxy-AmB)
Unclear the correct dose: 24-28% of the administerd dose is deposited in the trnsplanted lung(s); recommended mg, doubled if the patient is incubatet
The frequency could be every 2 weeks (long peristence in the BAL)
Clinical studies:
ABLC mg for 4 days, then 1/week up to 2 mts
ABLC vs deoxy-AmB: similar efficacy (11% vs 14%), better tolerability (14% vs 29%)
ABLC 50 mg pre Tx, 50 mg every 48 hrs up to 2 weeks after estubation, 1/week for 3-13 weeks after Tx; fluconazole allowed for the 1st month: 6 months f.u. in 60 pts: 1 (1.7%) colonization, 4 (7%) mild adverse events
Some programs use 1 dose every 2 weeks lifelong
Combination with systemic prophylaxis ?

23. Azoles High risk of interactions (Clin Infect Dis 2009; 48: 1441)
Therapeutic Drug Monitoring (TDM) is mandatory
Voriconazole TDM in CF LTx (Transpl Infect Dis 2009; 11:211)
Usual dose: 200 mg q12h after load,

24. Azoles High risk of interactions (Clin Infect Dis 2009; 48: 1441)
Therapeutic Drug Monitoring (TDM) is mandatory
Voriconazole TDM in CF LTx (Transpl Infect Dis 2009; 11:211)
Usual dose: 200 mg q12h after load,
14% neurologic effects, 30% liver toxicity
Increased levels of tacrolimus (dose reduction by factor 4)
Posaconazole and tacrolimus in CF LTx (Ther Drug Monit 2009; 31: 396): daily tacrolimus reducted by a factor 3 (2 mg/day)

25. Conclusions
At present fungal infections do not seem to represent a major challenge in patients with CF
ABPA and CVC-related candidemias are the most frequent clinical features, but invasive infections due to Aspergillus and Scedosporium are described with increasing frequency, especially after lung transplant
This scenario may change in the (next) future because of the overall increase in patients survival and therefore it is possible that fungal pathogens become (soon) a challenge also in CF
Considering the peculiarity of pharmacokinetics of drugs in CF and the great number of drugs administered to these patients, specific studies are needed in order to identify the correct schedules and the possible risk of adverse events due to drugs interactions