Safety profile of intravenous and subcutaneous siplizumab,an anti‐CD2 monoclonal antibody,for the treatment of plaque psoriasis: results of two randomized,double‐blind,placebo‐controlled studies

Several biologics targeting different cytokines and receptors, including T‐cell receptors, have been approved for psoriasis treatment. Siplizumab, a humanized anti‐CD2 monoclonal antibody, may potentially provide an alternative therapy for psoriasis. Its safety profile and immunogenicity was examined in adults with plaque psoriasis. Two multicenter phase II randomized, double‐blind, placebo‐controlled studies: one tested two intravenous (I.V.) doses (0.012 and 0.04 mg/kg) of siplizumab every 2 weeks × 8 doses (124 patients); the second study tested three subcutaneous (S.C.) dose regimens of siplizumab (5 mg × 12 weeks, 5 mg × 6 weeks + placebo × 6 weeks, 7 mg × 4 weeks + placebo × 8 weeks), and placebo × 12 weeks (420 patients). Adverse events (AEs) and laboratory values were monitored. Immunogenicity was determined by anti‐siplizumab antibodies quantification. In both studies, siplizumab exhibited an acceptable safety profile; most common AEs judged to be siplizumab related were lymphopenia, chills, and headache, reported at a higher frequency in the siplizumab‐treated vs. placebo group. Siplizumab‐related reductions in absolute lymphocyte count did not result in clinical evidence of immune suppression. Anti‐siplizumab antibodies were detected after exposure to siplizumab; however, there was no evidence of an association between antibody development and AEs. Siplizumab exhibited an acceptable safety profile in adult patients with plaque psoriasis when administered as multiple I.V. or S.C. doses. Higher, clinically relevant doses of siplizumab would need to be tested to fully assess its safety.     

Rearrangement of the T cell receptor gamma-chain gene in childhood acute lymphoblastic leukemia

We analyzed rearrangements of the T cell receptor gamma-chain (T gamma) gene as well as rearrangements of the T cell receptor beta-chain (T beta) gene and immunoglobulin heavy-chain (IgH) gene in 68 children with acute lymphoblastic leukemia (ALL). All 15 patients with T cell ALL showed rearrangements of both T beta and T gamma genes. Twenty-four of 53 non-T, non-B ALL patients (45%) showed T gamma gene rearrangements and only 14 of these also showed T beta gene rearrangements. Only a single patient rearranged the T beta gene in the absence of T gamma gene rearrangement. The rearrangement patterns of the T gamma gene in non-T, non-B ALL were quite different from those observed in T cell ALL, as 20 of 23 patients retained at least one germline band of the T gamma gene. In contrast, all T cell ALL patients showed no retention of germline bands. These data indicate that rearrangement of the T gamma gene is not specific for T cell ALL. Further, the results also suggest that T gamma gene rearrangement precedes T beta gene rearrangement. The combined analysis of rearrangement patterns of IgH, T beta, and T gamma genes provides new criteria for defining the cellular origin of leukemic cells and for further delineation of leukemia cell heterogeneity.     

Twenty Years of Active Bacterial Core Surveillance

Active Bacterial Core surveillance (ABCs) was established in 1995 as part of the Centers for Disease Control and Prevention Emerging Infections Program (EIP) network to assess the extent of invasive bacterial infections of public health importance. ABCs is distinctive among surveillance systems because of its large, population-based, geographically diverse catchment area; active laboratory-based identification of cases to ensure complete case capture; detailed collection of epidemiologic information paired with laboratory isolates; infrastructure that allows for more in-depth investigations; and sustained commitment of public health, academic, and clinical partners to maintain the system. ABCs has directly affected public health policies and practices through the development and evaluation of vaccines and other prevention strategies, the monitoring of antimicrobial drug resistance, and the response to public health emergencies and other emerging infections.     

The costs of treating external genital warts in England and Wales: a treatment pattern analysis

The objective of the study was to determine the cost implications of patterns of treatment for patients with external genital warts. A retrospective case note review was carried out at six genitourinary medicine (GUM) clinics in the UK. Significant variations in the total costs of care were observed across the clinics and across the choice of therapy. The cost per successful outcome was pound 221.81 for males and pound 211.07 for females. A minority of patients accounted for the majority of costs, for example the 30.1% of male patients who recorded six or more visits contributed 66.2% of the total cost. Costs also varied significantly by therapy sequence chosen. Patients who remained on their initial therapy experienced the lowest costs, with the extent to which patients shifted therapies substantially impacting on costs. Therapy sequences involving podophyllin were found to be the most expensive options in achieving a completed episode of care. We concluded that a high proportion of costs for GUM clinics is due to the failure of the initial therapy and by subsequent therapy switching. A greater emphasis on the selection of alternative treatment options, such as the patient-applied therapies, may help to reduce overall costs of care.     

Immunoglobulin secretory function of B cells from untreated patients with chronic lymphocytic leukemia and hypogammaglobulinemia: role of T cells

The mechanism of the hypogammaglobulinemia in patients with chronic lymphocytic leukemia (CLL) was studied by determining the generation of specific immunoglobulin-secreting cells in response to mitogen and antigen stimulation in culture. Normal peripheral blood B lymphocytes from 18 normal subjects cocultured with equal numbers of autologous T cells generated cells secreting 2,542 +/- 695 IgG, 2,153 +/- 615 IgA, and 2,918 +/- 945 IgM. Normal B lymphocytes cocultured with normal allogeneic T cells generated similar numbers. However, B lymphocytes from patients with chronic lymphocytic leukemia cocultured with T cells from the same patient generated only 0.5% as many cells secreting IgG and 11% and 23% as many secreting IgA and IgM, respectively. The reason for this markedly defective generation of immunoglobulin-secreting cells was investigated by evaluating T-helper, T-suppressor, and B-cell function using B cells from tonsil and T and B cells from peripheral blood of normal and leukemic individuals. T cells from patients with chronic lymphocytic leukemia provided somewhat greater help than did normal T cells to normal peripheral blood B cells and normal help to tonsil B cells, whether stimulated with mitogen or antigen. T cells from patients with chronic lymphocytic leukemia did not demonstrate increased suppressor function compared to normals with B cells from normal peripheral blood. The hypogammaglobulinemia in these patients therefore was associated with a markedly defective generation of immunoglobulin secreting cells, and as there was normal or increased T- cell helper activity without excessive suppressor activity, it seems likely that this was due to an intrinsic B-cell defect.     

Complement and cytokine response in acute Thrombotic Thrombocytopenic Purpura

Complement dysregulation is key in the pathogenesis of atypical Haemolytic Uraemic Syndrome (aHUS), but no clear role for complement has been identified in Thrombotic Thrombocytopenic Purpura (TTP). We aimed to assess complement activation and cytokine response in acute antibody‐mediated TTP. Complement C3a and C5a and cytokines (interleukin (IL)‐2, IL‐4, IL‐6, IL‐10, tumour necrosis factor, interferon‐γ and IL‐17a) were measured in 20 acute TTP patients and 49 remission cases. Anti‐ADAMTS13 immunoglobulin G (IgG) subtypes were measured in acute patients in order to study the association with complement activation. In acute TTP, median C3a and C5a were significantly elevated compared to remission, C3a 63·9 ng/ml vs. 38·2 ng/ml (P < 0·001) and C5a 16·4 ng/ml vs. 9·29 ng/ml (P < 0·001), respectively. Median IL‐6 and IL‐10 levels were significantly higher in the acute vs. remission groups, IL‐6: 8 pg/ml vs. 2 pg/ml (P = 0·003), IL‐10: 6 pg/ml vs. 2 pg/ml (P < 0·001). C3a levels correlated with both anti‐ADAMTS13 IgG (r_s = 0·604, P = 0·017) and IL‐10 (r_s = 0·692, P = 0·006). No anti‐ADAMTS13 IgG subtype was associated with higher complement activation, but patients with the highest C3a levels had 3 or 4 IgG subtypes present. These results suggest complement anaphylatoxin levels are higher in acute TTP cases than in remission, and the complement response seen acutely may relate to anti‐ADAMTS13 IgG antibody and IL‐10 levels.