Flow cytometric detection of leukemic blasts in Libyan pediatric patients with acute lymphoblastic leukemia.

The diagnosis of acute lymphoblastic leukemia (ALL), which is the most common type of cancer in children, has become more accurate with the use of flow cytometry. Here, this technology was used to immunophenotype leukemic cells in peripheral blood samples from Libyan pediatric ALL patients. We recruited 152 newly diagnosed patients at Tripoli Medical Center (Tripoli, Libya) by morphological examination of blood and bone marrow. Twenty-three surface and cytoplasmic antigen markers were used to characterize B and T cells in circulating blood cells by four-color flow cytometry. Six children (3.9%) turned out to have biphenotypic acute leukemia, 88 (57.9%) had B ALL, and 58 (38.1%) had T ALL. There were 68 cases of pro-B ALL CD10-positive (44.7%), 8 cases of pro-B ALL CD10-negative (5.2%), 6 cases of pre-B ALL (3.9%), and 6 of mature-B ALL (3.9%). CD13 was the most commonly expressed myeloid antigen in ALL. We present immunophenotypic data for the first time describing ALL cases in Libya. The reported results indicate that the most common subtype was pro-B ALL, and the frequency of T-ALL subtype was higher compared to previous studies. Six cases were positive for both myeloid and B lymphoid markers. Our findings may provide the basis for future studies to correlate immunophenotypic profile and genetic characteristics with treatment response among ALL patients.

Absolute CD4 count and percentage values among Libyan patients with HIV by single-platform flow cytometry.

BACKGROUND: Single-platform flow cytometry technology together with CD45-gating is becoming the method of choice for absolute CD4 T cell enumeration. Immunological assessment of HIV patients by monitoring CD4 can provide valuable information on antiviral treatment response and disease progression. METHODS: A total of 97 HIV-positive individuals were recruited from 2 hospitals in Tripoli, Libya, and 14 healthy blood donors. The HIV-infected individuals were classified by CD4+ count into HIV-positive (>200 cells/µL) or AIDS (≤200 cells/µL) groups. CD4+ and CD8+ cell counts were determined and compared among the groups and with similar published data. RESULTS: The mean ± SD CD4+ cell counts were 1106 ± 442.8 cells/µL in healthy individuals, 460 ± 219.7 cells/µL in the HIV-positive group, and 78 ± 64.3 cells/µL in the AIDS group. The mean ± SD CD4+/CD8+ ratio was 1.6 ± 0.58, 0.4 ± 0.22, and 0.1 ± 0.1, respectively. CD4+ counts in Libyan healthy adults might be higher than those reported in several studies in other regions, whereas CD4+ counts in Libyan AIDS patients seem lower. CONCLUSION: Reference values for T lymphocyte counts in Libyan healthy individuals should be investigated more extensively, and the reasons why Libyan AIDS patients seem to have such lower CD4+ counts should be examined.

Single ChAdOx1 nCoV-19 dose elicits stronger immune response in previously infected individuals than in SARS-CoV2 naive persons.

BACKGROUND: Current vaccines against COVID-19 effectively reduce morbidity and mortality and are vitally important for controlling the pandemic. Between December 2020 and February 2021, adenoviral vector vaccines such as ChAdOx1 (AstraZeneca-Oxford) were put in use. Recent reports demonstrate robust serological responses to a single dose of messenger RNA vaccines in individuals previously infected with SARS-CoV-2. We aimed to study the association between previous COVID-19 infection and antibody levels after a single dose of ChAdOx1 nCoV-19. METHODS: This cross-sectional study was conducted on 657 individuals who were either convalescent or SARS-CoV-2 naive and had received one dose of ChAdOx1 (AstraZeneca). A questionnaire was used to collect data on age, sex, and self-reported history of COVID-19 infection. We then compared the average levels of immunoglobulin G (IgG) between the previously infected and COVID-19-naive participants. RESULTS: We compared the antibody responses of individuals with confirmed prior COVID-19 infection with those of individuals without prior evidence of infection. The mean antibody levels in those who reported no history of COVID-19 infection were substantially lower than in those who were previously infected, in both males and females. Sex-related differences were observed when we compared antibody levels between men and women. In males, anti-S IgG antibody levels were higher in those who had been previously infected (156.1 vs. 87.69 AU/mL, p = .009), compared with the same pattern was observed in females (113.5 vs. 90.69 AU/mL, p = .005). CONCLUSIONS: Previous COVID-19 infection is associated with higher levels of SARS-CoV-2 antibodies following ChAdOx1 (AstraZeneca) vaccination. Our finding supports the notion that a single dose of ChAdOx1 nCoV-19 administered post-SARS-CoV-2 infection serves as an effective immune booster. This provides a possible rationale for a single-dose vaccine regimen for previously infected individuals.