ACTN1-related thrombocytopenia: Homozygosity for an ACTN1 variant results in a more severe phenotype.

ACTN1-related thrombocytopenia is a rare disorder caused by heterozygous variants in the ACTN1 gene characterized by macrothrombocytopenia and mild bleeding tendency. We describe for the first time two patients affected with ACTN1-RT caused by a homozygous variant in ACTN1 (c.982G>A) with mild heart valve defects unexplained by any other genetic variants investigated by WES. Within the reported family, the homozygous sisters have moderate thrombocytopenia and marked platelet macrocytosis with giant platelets, revealing a more severe haematological phenotype compared to their heterozygous relatives and highlighting a significant effect of allelic burden on platelet size. Moreover, we hypothesize that some ACTN1 variants, especially when present in the homozygous state, may also contribute to the cardiac abnormalities.

Pediatric Presentation of Antiphospholipid Syndrome: A Review of Recent Literature With Estimation of Local Prevalence.

We aimed to investigate the epidemiology, the clinical and laboratory characteristics of the pediatric involvement of antiphospholipid syndrome (APS), by performing a review of the current evidence and reviewing local experience in the Northwest Italy. To achieve this, we performed a detailed literature search to identify articles describing clinical and laboratory characteristics of pediatric APS. In concomitance, we conducted a registry-based study collecting data from the Piedmont and Aosta Valley Rare Disease Registry including pediatric patients diagnosed with APS in the last 11 years. The literature review led to inclusion of six articles with a total of 386 pediatric patients (65% females, 50% with systemic lupus erythematosus (SLE) as concomitant diagnosis). Rates of venous and arterial thrombosis were 57 and 35%, respectively. "Extra-criteria manifestations" included mostly hematologic and neurologic involvement. Almost one-quarter of patients (19%) reported recurrent events and 13% manifested as catastrophic APS. A total of 17 pediatric patients (mean age 15.1 ± 2.8, 76% female) developed APS in the Northwest of Italy. In 29% of cases, SLE was a concomitant diagnosis. Deep vein thrombosis was the most frequent manifestation (28%) followed by catastrophic APS (6%). The estimated prevalence of pediatric APS in Piedmont and Aosta Valley Region is 2.5/100,000 people, whereas the estimated annual incidence is 0.2/100,000 inhabitants. In conclusion, clinical manifestations of pediatric APS seem to be more severe and with a high prevalence of noncriteria manifestations. International efforts are needed to better characterize this condition and to develop new specific diagnostic criteria to avoid missed/delayed diagnosis in children with APS.

Successful use of antihistamines in severe hypereosinophilia.

Eosinophilia is common in childhood, and in most cases it is mild and of limited clinical relevance, being often secondary to allergy or infections. In rare cases, eosinophilia may be idiopathic or related to neoplastic aetiology. When severe and protracted, it can cause potentially irreversible organ or system damage, whose prevention is the first priority in the clinical management of hypereosinophilia. We describe the case of a patient with very severe eosinophilia, in whom antihistamines proved to be effective and safe in contributing to the eosinophil count normalization, thus avoiding the use of steroids until the hypothesis of an underlying neoplastic disorder was reasonably excluded.

Adrenal axis function after high-dose steroid therapy for childhood acute lymphoblastic leukemia.

BACKGROUND: A 4-week course of high-dose glucocorticoids may cause prolonged adrenal suppression even after a 9-day tapering phase. In this study, adrenal function and signs and symptoms of adrenal insufficiency were prospectively assessed in children with acute lymphoblastic leukemia (ALL) after induction treatment including high-dose prednisone (PDN) or dexamethasone (DXM). PROCEDURES: Sixty-four children with ALL, treated according to the AIEOP ALL 2000 Study protocol, underwent low dose ACTH (LD-ACTH) stimulation 24 hr after the last tapered steroid dose. In those with impaired cortisol response, additional LD ACTH tests were performed every 1-2 weeks until cortisol levels normalized. Signs and symptoms of adrenal insufficiency were recorded during the observation period. RESULTS: All patients had normal basal cortisol values at diagnosis. Twenty-four hours after last glucocorticoid dose, morning cortisol was reduced in 40/64 (62.5%) patients. LD-ACTH testing showed adrenal suppression in 52/64 (81.5%) patients. At the following ACTH test 7-14 days later, morning cortisol values were reduced in 8/52 (15.4%) patients and response to the test was impaired in 12/52 (23%). Adrenal function completely recovered in all patients within 10 weeks. No difference was found between patients treated with PDN or DXM. Almost 35% of children with impaired cortisol values at the first test developed signs or symptoms of adrenal insufficiency. One child developed a severe adrenal crisis during adrenal suppression. CONCLUSIONS: High-dose glucocorticoid therapy in ALL children may cause prolonged adrenal suppression and related clinical symptoms. Laboratory monitoring of cortisol levels and steroid coverage during stress episodes may be indicated.

Splenectomy in children with chronic ITP: long-term efficacy and relation between its outcome and responses to previous treatments.

This retrospective study was conducted to determine whether the response to splenectomy is related to the response to previous treatments. We examined the records of 90 children splenectomized for chronic ITP. Platelet counts were constantly>50x10(9)/L in 68 patients (75%). An improvement in the quality of life was observed in 79 (85%). The success of splenectomy was strongly correlated with a good response to previous treatment. A negative response to any of the prior treatments had no predictive value. This finding is relevant when elective splenectomy is considered as a treatment option.

Steroid withdrawal syndrome during steroid tapering in childhood acute lymphoblastic leukemia: a controlled study comparing prednisone versus dexamethasone in induction phase.

Children with acute lymphoblastic leukemia (ALL) receive as part of induction therapy a 4-week course of high-dose glucocorticoid, which is either abruptly discontinued or shortly tapered. The aim of this study was to evaluate the signs and symptoms of steroid withdrawal syndrome and performance status (according to Lansky scale) during the 9-day tapering period and 1 week after withdrawal of the steroid in 63 children randomly allocated to receive prednisone or dexamethasone as part of induction treatment according the AIEOP ALL 2000 protocol. Twenty of 28 (75%) patients on dexamethasone versus 18 of 35 (51.4%) on prednisone (P < 0.05) developed at least one steroid withdrawal symptom during the study period. Three or more symptoms were observed in 39.3% (11/28) of the dexamethasone group and 8.6% (3/35) of the prednisone group (P < 0.05). Dexamethasone patients developed clinical signs earlier (within 3 days from the steroid tapering) than symptomatic prednisone patients. In the prednisone group, the symptoms were less severe and the performance status was higher (P < 0.05). Steroid withdrawal morbidity in ALL children during induction is a frequent and clinically relevant complaint. A more gradual (for dexamethasone) or a more prolonged (for prednisone) tapering might be suggested.