Toxoplasma gondii pneumonia in liver transplantation: survival after a severe case of reactivation

Abstract

Toxoplasmosis is an infrequent infection in solid organ transplantation, except in heart transplantation, where the grafting of a positive organ in a negative recipient transmits the infection in a high percentage of cases, in the absence of prophylaxis. We report a case of pneumonia by Toxoplasma gondii in a woman who received a liver transplant and had pre-transplant positive serology. Diagnosis was made by cytologic examination of bronchoalveolar lavage fluid, where the parasite was observed with hematoxylin-eosin and Giemsa staining. That finding was confirmed by direct immunofluorescence and positive polymerase chain reaction. The patient had a favorable outcome, although she had not initially received first-choice drugs. This was a case of severe illness secondary to reactivation of Toxoplasma infection, diagnosed pre-mortem and with a favorable outcome. Duration of treatment and need for secondary prophylaxis in these patients are discussed in the literature. Although infrequent, toxoplasmosis must be considered among the differential diagnoses of pulmonary infiltrates in solid organ transplantation.

Temporal and Spatial Distribution of Toxoplasma gondii Differentiation into Bradyzoites and Tissue Cyst Formation In Vivo

“…However, several conditions may appear later in life that impair the function of the immune system and its ability to control the reactivation of T. gondii tissue cysts. These include infectious diseases such as human immunodeficiency virus infection (28-30) and treatment with immunosuppressive and chemotherapeutic agents commonly given to transplant and cancer patients, respectively (3,18,22,27,32,45). Reactivation of tissue cysts in these individuals leads to the recrudescence of T. gondii infection (15), a life-threatening condition that in the long term responds poorly to therapy and often develops into encephalitis (16,19,26,28,30,42).…”

Pulmonary toxoplasmosis in immunocompromised patients with interstitial pneumonia: a single-centre prospective study assessing PCR-based diagnosis

“…Pulmonary toxoplasmosis is a debateable concept as several authors consider this condition to be a disseminated form. However, this condition is thought to be rarer,15–17 and has been reported in far smaller numbers of SOT8 18 and HSCT patients 19 20. Pulmonary toxoplasmosis should be treated as a genuine emergency, but it can be difficult to diagnose: its clinical signs are not specific and serological testing is not entirely reliable in immunocompromised individuals 7 20…”

Toxoplasma reactivation after renal transplant – low expression of nitric oxide synthase and a Th2 pattern of immune response

“…Although other cells also produces IFN-γ, as dendritic cells, natural killer cells and CD4+ lymphocytes. Any disruption of this cascade can interfere with IFN-γ synthesis and loss of bradyzoites control 7 . When low levels of IFN-γ are present in the tissue, transformation of bradyzoites to tachyzoites occurs, allowing replication of this fast-growing forms and further disease reactivation.…”