*Solid organ transplant (SOT) recipients have a higher risk of developing TB compared with general population

*post transplant TB incidence depend on the epidemiology rather than the organ transplanted

*majority of posttransplant TB cases are due to reactivation of TB in the recipients BUTTransmission through allograft (donor-derived)

and new infection with community acquired TB can occur

Epidemiology

*Most cases of TB in recipient is secondary to reactivation of latent infection

*donors can be divided into low , moderate and high risk categories for active or LTBI based on social and medical history.

*donor-derived TB may be associated with donors who were born or lived for significant period in TB endemic area

*Diagnosis of LTBI and risk assessment for transmission in donors should be based on objective medical data (e.g. prior historical results of TST, IGRA and CXRs)

*History and physical exam*cultures and radiologic studies

*living donors TST or IGRA screening*deceased donors may have lung infiltrate due

to other causes cofounding the evaluation*residual pulmonary lesion:

lung transplant contraindication other organs can be considered under

certain situation*disseminated TB

-IGRA is more specific than TST -recent study showed that the rate of progression

to active TB among patients with positive IGRA is higher than those with positive TST

(14.6 % vs 203%** ) -Deceased donors with indeterminate or positive

IGRA should not be excluded from donation -for living donors with positive TST or IGRA,

transplantation can be delayed till active or latent TB is diagnosed

**Am J Respir Crit Care Med 2008; 177:1164-1170

Emergency transplantation

Indication for LTBI treatment-recipient who have 1 or more of the following

* PPD> 5mm* hx of untreated TB

* hx of contact with pt with active TB* pt with CXR findings compatible with TB

-recipient of an organ from donor with hx of untreated TB

Patient whose previous TB was properly treated DO NOT require further treatment for LTBI

Recommended regimens for LTBI *INH + vit B6 for 9 months

*alternatives: - rifampicin + / - INH for 4 months (B- 2)

- rifampicin + pyrazinamide for 2 months ( C-3)

*If active TB can not be ruled out?? Treat with 3 drugs ( INH + PZA + ethambutol)

-ve cultures + normal CXR continue INH only

*Rifampicin decreases the serum level of immunosuppressive agents high risk of graft rejection

*increase the dose of calcineurin inhibitors 3-5 folds and monitor the level

*rifabutin could be an alternative to rifampicin

Other anti TB-streptomycin and aminoglycosides risk of

nephrotoxicity with calcineurin inhibitors-fluoroquinolones is an alternative and can be

used as 1st line agent ( risk of resistant MTB)

-Linezolid can be used in case of drug resistance or drug related toxicity

thrombocytopenia , anemia and poly neuropathy

Duration of therapy

-INH + PZA + streptomycin for 9 months-oral regimens should be maintained for 12–18

months -the benefit of treatment with injectable agents

should be evaluated during the first 2–3 months in extensive or cavitary forms.

-One Spanish study showed increased mortality when anti TB is used for less than

9 months-another study document that the only factor

that is associated with greater risk of TB recurrence was the duration of therapyNO recurrence in pt who received more than 12 months treatment irrespective of rifampicin use

*Living donors with a positive TST or IGRA should be offered treatment for LTBI prior to donation

*completion of treatment may delay the transplant and adversely impact the recipient, expert opinion was that each situation should be individualized, but the prophylaxis need not be completed before the transplant.

*no data on optimal duration of LTBI therapy in this setting

*Chemoprophylaxis should be considered for recipients whose donor TST or IGRA was positive if donor did not receive either any or sufficient chemoprophylaxis.

*Recipient risk for INH toxicity must be weighed against the risk of donor-derived TB transmission

*drug interactions of transplant medicationsand rifamycins should also be carefully

considered after transplant .

References*Diagnosis and Management of Tuberculosis in

Transplant Donors: A Donor-Derived InfectionsConsensus Conference Report

American Journal of Transplantation 2012; 12: 2288–2300

* Tuberculosis in Solid-Organ Transplant Recipients:Consensus Statement of the Group for the Study of Infection in Transplant Recipients (GESITRA) of the Spanish Society of Infectious Diseases and Clinical Microbiolog

Clinical Infectious Diseases 2009; 48:1276–84.