Toxoplasmosis in patients with hematologic malignancies

Association between Toxoplasma gondii exposure and hematological malignancies: A systematic review and meta-analysis

The possible association between Toxoplasma gondii infection and hematological malignancies has been suggested by several studies. The current systematic review and meta-analysis was directed to further understand this relationship. In the present study, five electronic databases were reviewed for T. gondii infection in patients with blood cancer. The random effects model and 95% confidence intervals (CI) were used to determine the overall odds ratio (OR). Heterogeneity was deliberate with Cochran's Q test and I² statistic. In total, 13 studies including 1504 patients with hematological neoplasia and 2622 subjects without any malignancies were included in this meta-analysis. Overall, 324 patients with blood cancer and 391 subjects without any malignancies were exposed to Toxoplasma infection. The pooled random effect favored a statistically significant increased risk of T. gondii infection in patients with hematological neoplasia compared with non-cancer individuals [OR = 2.43; 95% CI: 1.49-3.97; χ2 = 49.7, I² = 75.9%, P = 0.00]. Also, significant pooled ORs of positive association were observed for studies which measured anti- Toxoplasma antibodies (IgG) [OR = 2.66; 95% CI: 1.46-4.83; χ2 = 40.3; I² = 82.6%, P = 0.00]. T-value and P-value were obtained 0.20 and 0.85 by Harbords modified regression test. This meta-analysis demonstrates that toxoplasmosis may be associated with an elevated risk of hematological malignancies. Also, it has found that immunoglobulin class and types of blood cancer are the specific sources of heterogeneity. Additional studies should be performed to examine the impact of T. gondii infection in the onset or development of hematologic neoplasms in the future.

Acute Toxoplasma Dissemination With Encephalitis in the Era of Biological Therapies

We report the case of a 65-year-old patient with pseudolymphoma who developed acute toxoplasmosis following 6 cycles of rituximab and bendamustine therapy. Acute toxoplasmosis in the setting of biological response modifiers, rather than reactivation, is a unique unreported infection. The patient developed severe disease with multi-organ involvement, including retinitis, myocarditis, and myositis. We discuss the clinical findings, epidemiology, and laboratory diagnosis.

Association between Toxoplasma gondii exposure and paediatrics haematological malignancies: a case-control study

The possible association between Toxoplasma gondii infection and paediatric haematological malignancies in a group of patients and control subjects was evaluated in the present study. We performed an age-, gender- and residence frequency-matched case-control study of 101 blood cancer patients under 18 years of age, all of which were treated in Amirkola Pediatric Hospital. One hundred and thirty-eight control samples were gathered from the outpatient clinic in the hospital. All cases and controls were tested for the presence of anti-Toxoplasma IgG antibodies and then IgG-positive subjects were evaluated for IgM antibodies by enzyme-linked immunoassays. Anti-T. gondii IgG antibodies were found in 37 (36.6%) of the cases and 12 (8.7%) subjects in the control group (odds ratio 6.07, 95% confidence interval 2.963-12.437, P < 0.0001). The median and interquartile range (IQR) of IgG titre from case group (7.7 (IQR 0.25-13.5)) was higher than the control (0.2 (IQR 0.1-0.5)) (P < 0.0001). The frequency of anti-T. gondii antibodies (IgG) in lymphoblastic leukaemia (acute lymphoblastic leukaemia), Hodgkin's lymphoma and T-cell lymphoma were 33 (31.9%), 3 (50%) and 1(100%), respectively. Anti-T. gondii IgM was not detected in the IgG-positive patients in case group. In the case subjects, no significant difference was seen in the positive rates of T. gondii infection between genders (37.3% in male; 35.7% in female; P = 0.52) and ages groups (P = 0.31). This study demonstrated that T. gondii infection is prevalent in children with blood cancer. It also showed that toxoplasmosis may possibly be linked with an increased risk of childhood haematologic malignancies. Furthermore, these results may be helpful in research on blood neoplasia aetiology.

Seroprevalence and risk factors of Toxoplasma gondii infection in oral cancer patients in China: a case-control prospective study

Over the recent years, potential associations between Toxoplasma gondii (T. gondii) infection and cancer risk have attracted a lot of attention. Nevertheless, the association between T. gondii infection and oral cancer remains relatively unexplored. We performed a case-control study of 861 oral cancer patients and 861 control subjects from eastern China with the aim to detect antibodies to T. gondii by enzyme-linked immunosorbent assay (ELISA) in these patients. The results showed that oral cancer patients (21.72%, 187/861) had a significantly higher seroprevalence than control subjects (8.25%, 71/861) (P < 0.001). Among them, 144 (16.72%) oral cancer patients and 71 (8.25%) control subjects were positive for IgG antibodies to T. gondii, while 54 (6.27%) oral cancer patients and 9 (1.05%) controls were positive for IgM antibodies to T. gondii. In addition, multiple logistic analysis showed that T. gondii infection in oral cancer patients was associated with blood transfusion history, keeping cats at home, and oyster consumption. To our knowledge, this is the first study that provided a serological evidence of an association between T. gondii infection and oral cancer patients. However, further studies are necessary to elucidate the role of T. gondii in oral cancer patients.

Anti-Toxoplasma gondii antibodies in patients with beta-hemoglobinopathies: the first report in the Americas

Background

In Brazil, there have been no previous studies of Toxoplasma gondii infection in sickle cell anemia patients and carriers of severe forms of beta-thalassemia. This study evaluated T. gondii infection in patients with beta-hemoglobinopathies.

Methods

A total of 158 samples, 77 (48.7%) men and 81 (51.3%) women, were evaluated. Three groups were formed: G1 (85 patients with sickle cell disease); G2 (11 patients with homozygous beta-thalassemia; G3 (62 patients with heterozygous beta-thalassemia). ELISA was employed to identify anti-T. gondii IgM and IgG antibodies, and molecular analysis was performed to determine beta-hemoglobin mutations. Fisher’s exact test was used to compare frequencies of anti-T. gondii IgM and IgG antibodies in respect to gender and age.

Results

Anti-T. gondii IgG antibodies were found in 43.5% of individuals in G1, 18.1% in G2 and 50% in G3. All samples from G1 and G2 were seronegative for anti-T. gondii IgM antibodies, but 3.2% from G3 were seropositive. Considering anti-T. gondii IgG antibodies, no statistical significant differences were found between these groups nor in seroprevalence between genders within each group. Despite this, comparisons of the mean ages between G1, G2 and G3 were statistically significant (G2 vs. G1: p value = 0.0001; G3 vs. G1: p-value <0.0001; G3 vs. G2: p-value = 0.0001).

Conclusion

A comparison by age of patients with sickle cell anemia showed a trend of lower risk of infection among younger individuals. Therefore, this study demonstrates that T. gondii infection occurs in patients with beta-thalassemia and sickle cell anemia in Brazil as seen by the presence of anti-T. gondii IgM and IgG antibodies.