The impact of the World Health Organization classification and clonality assessment of posttransplant lymphoproliferative disorders on disease management.

CONTEXT: The World Health Organization classification of posttransplant lymphoproliferative disorders divides them into 4 main categories. OBJECTIVE: To classify cases of posttransplant lymphoproliferative disorders diagnosed in our institution according to the World Health Organization scheme and correlate the classification and clonality with clinical data. DESIGN: Cases of posttransplant lymphoproliferative disorders were reviewed. They were classified according to the World Health Organization scheme. Clonality was determined by flow cytometry and/or polymerase chain reaction. Patients' charts were reviewed. RESULTS: Thirty-one cases were identified. Median age was 33 years. There were 19 cases of kidney, 8 cases of liver, and 4 cases of bone marrow transplant. Immunosuppression consisted of cyclosporin A and prednisone (N = 24) or FK506 and prednisone (N = 7). Twenty cases (63%) were World Health Organization type 3, 7 cases (23%) type 2, 3 cases (6.4%) type 1, and 1 case type 4 posttransplant lymphoproliferative disorder. Ten patients received chemotherapy, 20 patients had reduction of immunosuppression, and 1 had no treatment. Follow-up was available on 25 patients. Seven (43.75%) of 16 with type 3 lesions with available follow-up died of their disease. Five of these patients received reduction of immunosuppression alone. Only 2 of 9 patients with type 3 disease who received chemotherapy died of disease. Two patients with type 2 disease died of unrelated causes. One patient is alive with disease; the remaining patients with types 1 and 2 disease are alive with no disease. CONCLUSIONS: The World Health Organization classification of posttransplant lymphoproliferative disorders is valuable in the identification of subtypes. It helps identify early lesions (1 and 2) requiring reduction of immunosuppression and type 3 disease, which requires chemotherapy from the outset.

Chlamydia trachomatis infections among Yemeni school pupils in relation to environmental conditions.

OBJECTIVE: This study is aimed at establishing the prevalence of Chlamydia trachomatis infections among school pupils in Sana'a, Republic of Yemen, and to explore the association of infection with environmental and social factors. METHODS: A total of 787 school children, 529 boys and 258 girls, were randomly selected for enrollment in this study. Four hundred and twenty-nine were from 4 schools in Sana'a city, and 358 from 3 rural schools around Sana'a, Republic of Yemen. Questionnaire forms were filled in for each child to investigate environmental and social factors. Sera were tested for anti Chlamydia trachomatis IgG antibodies using enzyme-linked immunosorbent assay CTM-IgG . RESULTS: An overall rate of infection of 45.9% was determined. The rate of infection among rural pupils (73.2%) was higher (P<0.0001) than that among urbanones (23.1%). The rate of infection was found significantly (P<0.001) inversely correlated with age of the pupils. Environmental factors which were found to influence the infection rate were; rural residence, unplastered walls, mud floor, lack of stand pipe water, lack of latrine and presence of animals within dwelling with odds ratio of 9.1, 6.3, 6.1, 5.2, 3.7, 3.5 and 1.7. Also, the male sex and illiteracy of the parents has been found to be risk factors for infection. CONCLUSION: Prevalence of Chlamydia trachomatis infection was found to be high. The prevalence correlates inversely with age. Rural residence, environmental conditions and social factors were risk factors for infections. Yemen could be identified as a trachoma endemic area, which should be targeted by the control programs.