PM-Scl and Th/To in systemic sclerosis: a comparison of different autoantibody assays.

OBJECTIVE: To compare test characteristics of the Euroimmun line blot assay with other assays for two uncommon autoantibody specificities in systemic sclerosis (SSc). METHODS: Patients from the Johns Hopkins Scleroderma Center were assayed routinely using the Euroimmun platform. Patients positive for anti-Th/To (N = 73) and anti-PM-Scl (PM75 and/or PM100; N = 290) by Euroimmun were compared with SSc patients negative for these autoantibodies. For Th/To antibodies, the comparison assay was immunoprecipitation (IP), performed using 4 Th/To complex components: POP1, RPP40, RPP30, and RPP25. For anti-PM-Scl, IPs were performed with PM100 and PM75. Different Euroimmun cut-offs for assigning antibody positive status (≥ 15/+, ≥ 36/++, ≥ 71/+++) were examined. Kappa statistics were calculated to determine agreement between assays. RESULTS: The best performing thresholds for defining anti-PM-Scl positivity were both PM75 and PM100 ≥ 15/+ on Euroimmun, corresponding to a kappa statistic of 0.79, sensitivity 72% and specificity 100%. For anti-Th/To, kappa values were lower for all comparisons (κ < 0.5). Given the high sensitivity of defining anti-Th/To by ≥ 15/+ (91-95%), a potential approach is to use Euroimmun screening (15/+ cut-off), followed by confirmatory IP. CONCLUSION: Given the increasing utilization of Euroimmun and the importance of comparing data across cohorts, continued use of this platform is warranted, acknowledging discordance with IP for some specificities. For these, using a two-step approach (Euroimmun to maximize sensitivity, confirmatory assay to increase specificity) is suggested. KEY POINTS: • For less common SSc autoantibody specificities, some discordances exist between IP and Euroimmun LIA. • The best performing thresholds for defining anti-PM-Scl positivity were both PM75 and PM100 ≥ 15/+ on Euroimmun. • For Th/To, a two-step approach (Euroimmun to maximize sensitivity, confirmatory assay to increase specificity) is suggested.

Treatment results of 23 cases of severe aplastic anemia with lymphocytapheresis.

We report the results of 23 patients with aplastic anemia (AA) treated with a program of 14 lymphocytapheresis (LC). Treatments were performed with apheresis machines, models Haemonetics 30-S and Baxter CS3000, using the standard program. This procedure was done because AA in many cases appears as a result of the action of a T cell population that inhibits hematopoiesis. Theoretically, removal of this clonal population would produce hematopoietic recovery. Of the total of 23 patients, 9 were excluded for final evaluation of treatment results because 7 died during or shortly after treatment (0.7-3 months); one patient abandoned treatment after three LC and another died 7 months later because of transformation to acute leukemia. The remaining 14 patients were included in the final evaluation of treatment; seven females and seven males, average age 46.1 years (range 22-69); 13 with severe, and one with moderate AA; 11 with recently diagnosed, and 3 with chronic AA; 12 without previous treatment and two treated before with antilymphocyte globulin + oxymetholone (OXM) + cyclosporine A (CsA) with transient partial remission (PR). Besides lymphocytapheresis, 13 patients received OXM; 4 of them GM-CSF and one low dose CsA. Four patients had complete remission lasting > 59.5 months (range 42-78); eight PR (average duration of > 38.6 months), and two minimal remission (> 37 and 29 months). Platelet, reticulocyte and granulocyte counts increased on average at 48.7, 73.3 and 91.4 days, respectively. In conclusion, 14 (60.8%) of 23 patients with AA showed an improvement related to LC treatment, with a survival probability of 63% from the fourth month, the latter with an added beneficial effect of the other therapies used. Larger numbers of patients have to be treated with LC to determine its real usefulness, mechanism of action and the best conditions for its use.

[Treatment of paroxysmal nocturnal hemoglobinuria with antilymphocyte globulin]. / Tratamiento de la hemoglobinuria paroxística nocturna con globulina antilinfocitaria.

OBJECTIVE: To evaluate the effectiveness of antilymphocyte globulin therapy (ALG) in patients with paroxysmal nocturnal hemoglobinuria (PNH). DESIGN: Prospective, non-controlled trial. SETTING: Hematology Service, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS, Mexico City. PATIENTS: Six patients were included. The median age was 37.5 years and the male/female ratio was 1:1. All the patients had clinical disease consistent with PNH (hemolytic anemia with some degree of transient or persistent pancytopenia) and also erythrocytes with enhanced sensitivity to complement mediated lysis in vitro, as documented by either the Ham test or the sucrose lysis assay. The criterion for severity was the existence of continuous hemolysis in all and transfusion requirements of two or more packed red cells per month in four cases. Prior to ALG therapy, androgens and/or steroids had been given to five patients with no improvement. INTERVENTION: A single batch of ALG was used during the trial (E 0034, Lymphoglobulin Mérieux, Lyon, France). Patients received an infusion of 10 mg/kg per day in a 20 hours lapse during four consecutive days. Also 500 mg/day of methylprednisolone were started simultaneously with the ALG; it was given for seven days and was gradually tapered off and stopped on day 30. MEASUREMENTS: The increases in hemoglobin, granulocytes and/or platelets as well as decreases in red cell transfusion requirements were used to evaluate the results of therapy. RESULTS: Two patients suffered anaphylaxis after the first administration of ALG and were withdrawn from the study. Two of the four remaining patients responded, one response was total and the other minimal. The responses were transient, and no response was seen in the follow-up of 11-14 months. CONCLUSION: ALG therapy for PNH in the doses and time periods used by us had no beneficial effect in patients with a severe form of PNH.