Variable presentation of primary immune deficiency: two cases with CD3 gamma deficiency presenting with only autoimmunity.

BACKGROUND: CD3 chain expression defects including CD3 gamma, epsilon, delta, and zeta chain subunits, are autosomal recessive inherited severe combined immunodeficiencies (SCID). The phenotype is usually T-B+NK+ SCID with lymphopenia where the clinical findings may be mild (CD3γ) or severe (CD3δ, ε, ζ) owing to the underlying molecular defect. There is limited information about the disease in literature. METHODS: Here, we present two siblings from non-consanguineous family with autoimmunity including Evans syndrome, autoimmune hepatitis, nephrotic syndrome, and Hashimoto's thyroiditis and with no previous history of infections. To define the molecular basis of the disease, we performed linkage analysis around the CD3 receptor cluster and found consistent linkage to this region. RESULTS: The patient one displayed low TCRαß expression, low IgG, low IgA, low IgM, low CD3, low CD4, low CD8. The patient two also displayed low TCRαß expression and low anti-HBs titer. We went onto identify a homozygous splicing mutation (IVS2-1G>C) in the two affected individuals in the CD3γ gene. DISCUSSION: To date, only four cases have been reported with CD3γ deficiency. Occasionally, the patients present with only autoimmunity including autoimmune hemolytic anemia, vitiligo, Hashimoto's thyroiditis, and autoimmune enteropathy. However, Evans syndrome, autoimmune hepatitis, and nephrotic syndrome have not been reported in previous cases. We believe that our cases will contribute to the literature.

SLFN14 mutations underlie thrombocytopenia with excessive bleeding and platelet secretion defects.

Inherited thrombocytopenias are a group of disorders that are characterized by a low platelet count and are sometimes associated with excessive bleeding that ranges from mild to severe. We evaluated 36 unrelated patients and 17 family members displaying thrombocytopenia that were recruited to the UK Genotyping and Phenotyping of Platelets (GAPP) study. All patients had a history of excessive bleeding of unknown etiology. We performed platelet phenotyping and whole-exome sequencing (WES) on all patients and identified mutations in schlafen 14 (SLFN14) in 12 patients from 3 unrelated families. Patients harboring SLFN14 mutations displayed an analogous phenotype that consisted of moderate thrombocytopenia, enlarged platelets, decreased ATP secretion, and a dominant inheritance pattern. Three heterozygous missense mutations were identified in affected family members and predicted to encode substitutions (K218E, K219N, and V220D) within an ATPase-AAA-4, GTP/ATP-binding region of SLFN14. Endogenous SLFN14 expression was reduced in platelets from all patients, and mutant SLFN14 expression was markedly decreased compared with that of WT SLFN14 when overexpressed in transfected cells. Electron microscopy revealed a reduced number of dense granules in affected patients platelets, correlating with a decreased ATP secretion observed in lumiaggregometry studies. These results identify SLFN14 mutations as cause for an inherited thrombocytopenia with excessive bleeding, outlining a fundamental role for SLFN14 in platelet formation and function.

High on-treatment platelet reactivity in patients with ischemic cerebrovascular disease: assessment of prevalence and stability over time using four platelet function tests.

High on-treatment platelet reactivity (HTPR), referred to as a higher than expected platelet reactivity in patients under antiplatelet therapy, could influence outcome in cerebrovascular disease (CVD), but its prevalence and its stability over time is uncertain. Platelet reactivity was assessed in 18 patients with ischemic stroke/transient ischemic attack (TIA) 7 days (D7) and 90 days (D90) after prescription of clopidogrel, using four methods: light transmission aggregometry with 5 µmol/l ADP (LTA-ADP), vasodilator-stimulated phosphoprotein (VASP), Verify Now P2Y12 and platelet function analyzer (PFA) P2Y. HTPR was defined as LTA-ADP more than 46%; PFA-100-P2Y closure time less than 106 s; VerifyNow P2Y12, PRU greater than 235, VASP, PRI greater than 50%. Patients displayed, both at D7 and D90, a marked inhibition of platelet reactivity towards ADP in all tests as compared with reference levels. Correlations between the results obtained with all the tests at D7 and D90 and between measurements on each day in each test were low-to-moderate. The prevalence of HTPR for all the tests was 40% at D7 and 42% at D90. There was a moderate degree of agreement (k statistic < 0.5) between tests with regard to categorizing patients as HTPR/No-HTPR (D7 and D90). The on-clopidogrel platelet reactivity phenotype, HTPR/No-HTPR, remained stable in 55-72% of patients, depending on the test. A high prevalence of HTPR is found among CVD patients treated with clopidogrel and this platelet reactivity phenotype remains over time. There is poor agreement between the different platelet function tests for categorizing the platelet reactivity phenotype in these patients. The new PFA-100 P2Y equals other platelet function assays for evaluating HTPR in CVD.

Evaluation of platelet function during extended storage in additive solution, prepared in a new container that allows manual buffy-coat platelet pooling and leucoreduction in the same system.

BACKGROUND: A novel and practical storage container designed for manual buffy-coat pooling and leucodepletion was evaluated to assess its filtration performance and to analyse the quality of stored leucoreduced buffy-coat-derived platelet pools. MATERIALS AND METHODS: To analyse the grifols leucored transfer PL system, blood was collected from random donors into standard triple bag systems, and fractionated using standard procedures to obtain buffy-coats. Ten leucodepleted platelet pools were prepared each from five units of buffy-coats in additive solution. Concentrates were stored for 10 days at 22 °C on an end-over-end agitator. On days 0, 5, 7, and 10 of storage, samples were tested using standard in vitro platelet parameters. RESULTS: The use of this novel system for volume reduction and leucodepletion of buffy-coats resuspended in additive solution led to platelet pools that met the European requirements. pH was maintained well, declining from an initial value of 7.11±0.04 to 6.88±0.08 after 10 days. Parameters of cell lysis, response to a hypotonic stimulus and aggregation induced by agonists (arachidonic acid, ristocetin, collagen or thrombin receptor activating peptide) were also well-preserved. During storage, the quality profile of the platelet pools remained very similar to that previously reported in platelet concentrates in terms of metabolism, platelet activation (CD62, CD63, sCD62), expression of glycoproteins Ib and IIb/IIIa, capacity of glycoprotein IIb/IIIa to become activated upon ADP stimulation, and release of biological response modifiers (sCD40L and RANTES). DISCUSSION: This new system allows the preparation of leucodepleted buffy-coat platelet pools in additive solution with good preservation of platelet function. The logistics of the procedure are relatively simple and it results in good-quality components, which may reduce costs and ease the process of buffy-coat pooling and leucocyte reduction in transfusion services.