幼年型粒单核细胞白血病的临床及实验室特征分析

目的 分析幼年型粒单核细胞白血病（JMML）的临床与实验室特征。方法 对10例初诊JMML患者的临床特征及实验室结果进行回顾性分析,并与同期确诊的28例骨髓增生异常综合征（MDS）、44例慢性粒细胞白血病（CML）患儿进行对比。结果 与CML及MDS患者相比,JMML患儿皮疹、瘀斑及淋巴结肿大的出现几率较高,而血清胆碱酯酶（ChE）最低。JMML患儿抗碱血红蛋白（HbF）最高,白细胞计数高于MDS组而低于CML组,粒红比与病态造血比例分别低于CML与MDS组;JMML组成熟单核细胞标记CD14表达较高,髓系标记CD33、CD11b、CD13及CD15的表达高于MDS组而低于CML组,差异均有统计学意义（P < 0.05）,CD7及CD2高于CML组而低于MDS组（P < 0.05）。结论 JMML患儿皮疹、瘀斑、淋巴结肿大以及ChE降低较为多见,骨髓病态造血现象较少,CD14表达明显增高。     

Extramedullary infiltration at diagnosis and prognosis in children with acute myelogenous leukemia

BACKGROUND: Extramedullary infiltration (EMI) is an occasional clinical symptom in childhood acute myelogenous leukemia (AML), but there is considerable controversy regarding the prognostic significance of EMI in AML. PROCEDURE: We evaluated the frequency and prognostic significance of EMI at diagnosis of AML in children. RESULTS: Of 240 cases of de novo AML excluding children with Down syndrome and acute promyelocytic leukemia, 56 (23.3%) showed EMI at diagnosis. Patients with EMI had a higher initial WBC count and a higher proportion of M4/M5 morphological variants. The complete remission rate following induction chemotherapy was lower in patients with EMI. However, the overall survival and event-free survival did not differ between patients with and without EMI. A detailed analysis showed that patients with EMI with a WBC count at diagnosis of over 100 x 10(9)/L or infiltration into the central nervous system are likely to have a poor prognosis. CONCLUSIONS: CNS leukemia and EMI together with a WBC count of >100 x 10(9)/L at diagnosis of AML are high risk factors for relapse, and alternative treatment approaches for patients with these characteristics should be explored.     

Early complications in children with acute lymphoblastic leukemia presenting with hyperleukocytosis

BACKGROUND: The optimal management of childhood acute lymphoblastic leukemia (ALL) with hyperleukocytosis is unclear, largely because the risk of leukostasis-related complications is poorly characterized. PROCEDURE: We reviewed the presenting characteristics, initial management, and frequency and type of complications in all children seen at St. Jude Children's Research Hospital with previously untreated ALL and an initial leukocyte count >200 x 10(9)/L. RESULTS: A total of 178 children, representing 8% of all children with ALL, had an initial leukocyte count >200 x 10(9)/L; 67 patients had a leukocyte count >400 x 10(9)/L. Sixteen patients (9%) had neurological complications with 12 of these patients experiencing symptoms at presentation. Four patients (2%), all with initial leukocyte counts >400 x 10(9)/L, suffered a CNS hemorrhage. Pulmonary leukostasis occurred in 11 patients (6%). The degree of hyperleukocytosis was significantly predictive of neurological (P = 0.006) and respiratory (P = 0.014) complications. The majority of complications occurred at presentation. Cytoreduction (94 patients) decreased the leukocyte count but delayed initiation of chemotherapy (P = 0.013). CONCLUSIONS: Serious leukostasis-related complications are relatively uncommon in childhood ALL and most occur at presentation. Their incidence increases in proportion to the leukocyte count. A large subset of cases can be managed successfully without cytoreduction. Cytoreduction may be considered for patients with leukocyte counts >400 x 10(9)/L or patients who have complications at presentation.     

Relationship between high leukocyte count and cell size in childhood acute myeloblastic leukemia

In order to determine the significance of cell size together with high leukocyte count (>30x10(9)/L) in acute myeloblastic leukemia (AML), we evaluated the percentages of small, medium and large cells in 33 children with AML. All of the 10 patients with a high leukocyte count and 14 of the 23 patients with a low leukocyte count (<30x10(9)/L) died or experienced a relapse within the first year. The mean small cell percentage of patients with high leukocyte counts was significantly lower than that of patients with low leukocyte counts (p<0.05). The percentages of small, medium and large cells of patients with high leukocyte counts and of patients with low leukocyte counts who died or experienced a relapse within the first year were similar. The percentage of medium cells of patients with high leukocyte counts was significantly higher than that of surviving patients with low leukocyte counts (p<0.05). The mean percentages of small, medium and large cells were similar in patients who died or experienced a relapse and surviving patients with low leukocyte count. We conclude that cell size has prognostic significance when the leukocyte count at admission is over 30x10(9)/L, although confirmation seems necessary with a larger population of patients.     

Allogeneic bone marrow transplantation in children with chronic myelogenous leukemia

PURPOSE: To determine the outcome of children undergoing allogeneic bone marrow transplantation for chronic myelogenous leukemia (CML) at the authors' institution. PATIENTS AND METHODS: Between 1985 and 1999, 18 allogeneic bone marrow transplantations were performed in 17 patients with CML at the Hospital for Sick Children in Toronto. Median age at diagnosis was 9.5 years (range 3-17). Fourteen patients had disease in the first chronic phase, one had disease in the second chronic phase, and two had disease in the accelerated phase. Preparative regimens varied, with radiation-based protocols used in eight patients. Thirteen donors were related (11 matched, 2 mismatched); four were unrelated (2 matched, 2 mismatched). Patients received T-cell-replete bone marrow a median of 7.5 months (range 2.2-22) from diagnosis. A median of 3.0 x 10(8)/kg nucleated cells was infused (range 1.6-6.7). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methotrexate in 13 children. cyclosporine in three, and methotrexate in one. RESULTS: Primary graft failure occurred in one patient. Grade 2 acute GVHD or more developed in 11 of the 17 children (64%; grade 2 in 4, grade 3 in 7). Chronic GVHD occurred in 6 of the 16 patients at risk (37.5%; 5 extensive, 1 localized). No patient experienced overt or cytogenetic relapse. There were two deaths (12%): one from acute GVHD and cytomegalovirus pneumonia and the other from chronic GVHD. Probability of 5-year event-free survival was 87 +/- 9%. CONCLUSIONS: These results strongly support the practice of allotransplantation in children with CML, even in the setting of advanced disease and histoincompatibility. Efforts should be aimed at reducing the transplantation-related death rate.     

Pattern of pediatric chronic myeloid leukemia in Sudan and hematological response to imatinib

Chronic myeloid leukemia (CML) is infrequent in children. The best-known treatment is stem cell transplant. In a country with limited resources like Sudan, such expensive therapy is not available. Alternative approaches are needed to help these children. The tyrosine kinase inhibitor-imatinib-might be an answer to this problem. The objective of this study is to determine the pattern of children with CML, their hematological response to imatinib, and tolerance and side effects to this drug. All patients with confirmed BCR-ABL by polymerase chain reaction (PCR) were included in this study. The relevant data were collected and the patients were started on imatinib. Response to treatment was assessed clinically and hematologically only. Cytogenetics and molecular studies are not available. The average age of the 31 patient evaluated was 8.7 years, 2 patients were less than 1 year, and 5 patients, ie, 16%, were 2 years old or less. Chloroma was observed in 6 (19%) patients. The average of the white blood cell (WBC) count was 206.6 x 10(9)/L and the platelet count average was 523 x 10(9)/L. Two (6.5%) of the 31 patients presented as acute myeloid leukemia (AML). All patients had hematological remission within 2 months. Twenty-three (74%) had a sustained remission over an average follow-up period of 26 months (2-67 months). Six (19%) patients died with AML or sepsis. Side effects to imatinib were infrequent, observed in 4 out of 29 (13.7%) patients, and mild. One patient only needed dose modification. No resistance was observed during this period. CML patients present at an earlier age than in other parts of the world. Imatinib is safe and effective in treating pediatric CML where stem cell transplant in not available. Further cytogenetics are important to monitor response and proper management.     

Outcomes of juvenile myelomonocytic leukemia patients after sequential therapy with cytarabine and 6-mercaptopurine

Abstract

Juvenile myelomonocytic leukemia(JMML) is a pediatric myeloproliferative disorder. Allogeneic hematopoietic stem cell transplant (HSCT) is the only curative treatment for JMML. Pre-transplant therapy is a matter of controversy, and there are no firm recommendations. Whether chemotherapy is effective in achieving durable remission is questionable. Patients diagnosed as JMML at our center from January-2014 to December-2019 were retrospectively analyzed. All patients treated with at least one cycle of sequential therapy with subcutaneous cytarabine and oral 6-mercaptopurine were further assessed. The total number of patients diagnosed during the study period was 33. Patients were divided into two groups: patients who did not get any chemotherapy (n?=?13) and ones who received at least one cycle of chemotherapy(n?=?20). Age, total leukocyte count (TLC), monocyte percent, platelet count and spleen size were comparable between the two groups. There was no difference in the overall survival between the two groups, but 6 out of 20 patients showed a response to chemotherapy (2 complete remission, 4 partial remission). Two patients out of 20 underwent hematopoietic stem cell transplant (HSCT). The patients who achieved complete remission received 12 cycles of chemotherapy and have been in follow up for 28?months and 50?months respectively. Our results showed that sequential therapy with 6-mercaptopurine and cytarabine may be offered to patients in whom HSCT is not feasible or as a bridge therapy in those awaiting HSCT. The advantages of this approach include low cost, out-patient management and decreased requirement of blood components. In a subset of patients it may achieve remission.     

Hematological changes and predictors of bone marrow recovery in patients with neutropenic episodes in acute lymphoblastic leukemia

A total of 30 episodes of neutropenia in 16 patients of acute lymphoblastic leukemia, aged between 1 and 12 years were studied prospectively. In the initial treatment phase (induction of remission, consolidation and CNS prophylaxis) 92.8 per cent episodes were prolonged (> 7 days) and 85.7 per cent of them had profound neutropenia (absolute neutrophil counts < 0.200 x 10(9)/l). In contrast, in the maintenance phase, only 64.2 per cent were of prolonged duration; of them 57.1 per cent had profound neutropenia. Most patients in neutropenia of prolonged duration had anemia (Hb < 8 g/100 ml) and thrombocytopenia (platelet < 100 x 10(9)/l). Regularly increasing trends were seen in total leucocyte counts (TLC), absolute monocyte counts (AMC) and platelet counts from 4 days prior to recovery of absolute neutrophil counts (ANC). Of all the parameters, platelet count (> 100 x 10(9)/l) and AMC (> 0.1 x 10(9)/l) recovered 4 and 1 days, respectively, prior to recovery of ANC above 0.5 x 10(9)/l. Recovery of platelet counts (4 days prior to recovery of ANC) and possibly AMC can be considered early predictors of bone marrow recovery. These parameters can be used in conjunction with clinical condition to decide about early discharge of leukemia patients with neutropenia, especially in developing countries where prolonged stay can result in hospital acquired infections.     

非血缘相关脐血移植治疗儿童高危白血病的临床观察

目的：非血缘脐血具有快速寻求、容易得到和HLA配型不严格的特点，该文进行了非血缘相关脐血移植（UD-UCBT）治疗儿童恶性白血病的研究并探讨其疗效问题。方法：对6例难治性白血病患儿，包括3例急性淋巴细胞白血病（2例高危CR1，1例标危CR2），2例幼年慢性粒单细胞白血病（1例缓解期，1例加速期）和1例急性髓系白血病（AML- M5，CR1）进行了非血缘相关脐血移植，HLA高分辨1例全相合，1例5个位点相合，1例4个位点相合，3例3个位点相合。预处理选用白消安/环磷酰胺/ATG或全身放疗/环磷酰胺/ATG为主方案。于 0 d 回输脐血，有核细胞中位数为8.51×107/kg，CD34+细胞中位数为1.81×105/kg。预防移植物抗宿主病（GVHD）采用环孢霉素A、甲基泼尼松龙和骁悉或CD25单抗。结果：中性粒细胞绝对值（ANC）≥0.5×109/L和PLT≥20×109/L的中位天数分别是+13 d、+30 d，移植证据均为供者型。4例出现Ⅰ~Ⅲ度GVHD，均控制。随访中位时间12个月，未发生慢性GVHD，现存活4例血型均转为供者型，无复发。结论：脐血提供快速有效的造血干细胞，为治疗儿童白血病提供良好时机，非血缘相关脐血移植能耐受HLA多个位点不相合。急性GVHD发生率也较高，存在移植物抗白血病作用。     

Second allogeneic hematopoietic stem cell transplantation for juvenile myelomonocytic leukemia: case report and literature review

Juvenile myelomonocytic leukemia (JMML) is a rare clonal myeloproliferative disease in young childhood. Hematopoietic stem cell transplantation (HSCT) is the only way to cure the disease, but relapse after HSCT remains a major cause of treatment failure. A 5-year-old girl with JMML, who had experienced a relapse after the first transplant, did not respond to donor lymphocyte infusion and withdrawal of immune-suppressing agents. She was successfully treated using a second transplant. Detailed reports from the English literature since 1988 relating to a total of 13 JMML patients undergoing a second transplant were reviewed. Seven of the 13 JMML patients (54%) were alive and disease-free, with a median follow-up of 53 months after the second transplant. Within the first 6 months following the initial transplant, 10 JMML patients suffered either autologous recovery (n = 6) or early relapse (n = 4). Seven of the 10 (70%) were alive, with a median survival period of 53 months after the second transplant. Six JMML patients underwent retransplantation within 6 months of the first transplant, with three of these (50%) alive at follow-ups of 24, 57, and 90 months after the second procedure. The authors conclude that a second transplant within 6 months may be worth considering for JMML patients who experience autologous recovery or earlier relapse after the first transplant.     

儿童第二次非血缘供者造血干细胞移植2例

目的探索非血缘造血干细胞移植后复发病例进行第二次移植的可行性。方法患幼年型慢性粒单细胞性白血病(JMML)及重型β-地中海贫血的两例患儿接受非血缘供者造血干细胞移植后分别于移植后的10个月和1个月后原疾病复发,前者给予福达华加环磷酰胺预处理后输注原供者干细胞,降低预防移植物抗宿主病强度;后者给予含TBI预处理,移植另一非血缘供者外周血干细胞。结果两例患者第二次移植后均获得稳定植入,JMML患者并发急慢性移植物抗宿主病,完全缓解至+24月;地中海贫血患者已完全脱离输血状态至+23月。结论对于非血缘造血干细胞移植后复发的患儿,第二次非血缘供者造血干细胞移植是可行的。     

Alpha-interferon therapy induces improvement of platelet counts in children with chronic idiopathic thrombocytopenic purpura

PURPOSE: To investigate alpha-interferon (IFN) therapy for children with chronic idiopathic thrombocytopenic purpura (ITP). PATIENTS AND METHODS: Patients with refractory ITP lasting more than 12 months from diagnosis were included if they had platelet counts <50 x 10(9)/L and had received no treatment during the past month. Patients received IFN (3 x 10(6) U/m2 per dose), three times per week for 4 weeks; if partial (<150 x 10(9)/L) or no response was obtained, the same dose was continued for another 8 weeks. In patients with favorable response and subsequent decrease to pre-treatment values, an additional 4 weeks of treatment could be administered. RESULTS: Fourteen patients (ages 4-20 y) receiving 17 IFN courses were included. Mean initial platelet count was 29 +/- 15 x 10(9)/L. A significant increase was achieved during 14 of 17 courses (82.4%). All but two responses were transitory, and platelets returned to initial values after IFN discontinuation (mean 44 +/- 26 days). Considering the best response achieved by each patient, we observed: 1) 10 patients who achieved a sustained improvement of platelet count throughout the treatment period, decreasing to initial values after therapy was stopped; 2) one patient who achieved platelet count >150 x 10(9)/L, remaining with normal platelets at 18 months; 3) one patient who achieved platelet count >150 x 10(9)/L, remaining with platelets between 100 and 140 x 10(9)/L at 48 months; 4) one patient who had no response; and 5) one patient in whom therapy worsened the thrombocytopenia. A mild to moderate flu-like syndrome and a moderate decrease of the absolute neutrophil count were the only side effects observed. CONCLUSION: Interferon therapy induces a significant increase of platelet count and seems to be a valid alternative therapy to attempt the achievement of prolonged remission in refractory ITP, to defer splenectomy in younger children, or to improve platelet count before planned splenectomy.     

Acute megakaryoblastic leukemia in children identified by immunological marker studies

Acute megakaryoblastic leukemia (AMkL), defined by the presence of the platelet-associated glycoprotein IIb/IIIa complex on malignant cells, was diagnosed in 4 (4%) of 103 consecutive children with untreated acute leukemia or 4 (21%) of 19 children with acute nonlymphoblastic leukemia (ANLL). Particular features in the four children with AMkL were an age below 12 months at diagnosis (two patients), the absence of a significant hepatosplenomegaly (three patients), a leukocyte count below 20 x 10(9)/L with only a few blast cells in the peripheral blood (four patients), a technically difficult bone marrow aspiration (three patients), the presence of many megakaryocytes in marrow particles (two patients), and an inconclusive cytochemistry (four patients). The four children with AMkL were treated according to protocols for ANLL and a complete remission was obtained in all patients. One patient died from relapse after 3 months, one patient is a long-term survivor (38+ months), and two patients still on chemotherapy are disease-free for 11+ and 13+ months.     

Peripheral blood stem cell transplantation in young children: experience with harvesting, mobilization and engraftment

The purpose of this study was to determine the feasibility and assess optimal timing of harvesting peripheral blood stem cells (PBSC) for transplantation in young children. Thirteen children with body weight less than 25 kg, mean age of 3.9 years (1-9 yrs) who had recurrent solid tumors and leukemia were given tumor specific chemotherapy followed by i.v. rhG-CSF (5 microg/kg/d) for stem cell mobilization. Cytaphereses were done through a central venous line (CVL) during the marrow recovery phase (WBC >0.5 x 10(9)/l). The phereses were analyzed separately and assigned to three groups depending on the WBC at the time of the pheresis: Group I (WBC <1.0 x 10(9)/l), Group II [WBC in the range 1.0-3.0 x 10(9)/l] and Group III (WBC >3.0 x 10(9)/l). Samples from each harvest were assayed for cell count, CFU-GM, BFU-E, CD34+ cell count, and tumor cell immunocytology in patients with neuroblastoma (NBL). A median of 3.2 x 10(8) mononuclear cells per kg (MNC/kg), [mean 2.8 x 10(8) MNC/kg, standard error of the mean (SEM) +/- 0.74 (1.1-4.7)] were infused following myeloablative therapy. 78 phereses were performed in 13 children with a median weight of 18 kg (10-25 kg). A median of 5 phereses were performed per patient. There were no significant differences in the percentage and number of CD34+ cells, CFU-GM or BFU-E colonies assayed by plating 0.5 x 10(5) cells. Differences could be found in the total number of MNC (p<0.008) and the number of MNC/kg (p<0.001) between Groups II and III. No tumor cell contamination was detected in the NBL patients by immunocytology. All patients were rescued with PBSC and achieved sustained white cell engraftment (ANC >0.5 x 10(9)/l) at a median of 13.5 d (10-25 d) and platelet engraftment (untransfused platelet count >20.0 x 10(9)/l) at a median of 29 d (12-63 d). The only toxicity encountered during the phereses was thrombocytopenia in 4 patients whose median post-pheresis platelet count was 6.0 x 10(9)/l (3.0-9.01). It is concluded that collection of PBSC in young children is feasible and safe and can be performed through a cuffed CVL at the time of WBC recovery post mobilization with chemotherapy and G-CSF. Cytopheresis can be effectively performed when the peripheral WBC count approaches 1.0 x 10(9)/l. Following stem cell infusion, engraftment was prompt and durable.     

Immune thrombocytopenic purpura in childhood in Norway: a prospective, population-based registration

A prospective, population-based registration of children with immune thrombocytopenic purpura (ITP) was performed in Norway in 1996 and 1997. Ninety-two cases were identified, indicating an incidence of 5.3 per 100,000 children under 15 years. The sex ratio (female/male) was 1.2/1. Fifty-six percent presented with cutaneous signs only. The lowest platelet count was < 20 x 10(9)/L in 91%. In spite of mild bleeding symptoms, medical treatment was given in 68%, in most cases (57/63) with intravenous immunoglobulin. A total of 41/44 patients with platelet counts of < or = 5 x 10(9)/L were treated, regardless of whether they had mucous bleedings or not. Eighteen percent had platelet counts < 150 x 10(9)/L at 6 months, and 9% at 12 months following diagnosis. One patient with therapy-resistant chronic ITP died 16 months after diagnosis from an anesthesia complication related to profound epistaxis. This study shows a relatively high incidence. As in other studies, there was a tendency to treat platelet counts rather than bleeding symptoms.     

Elevated p53 Protein Expression; A Predictor of Relapse in Rare Chronic Myeloid Malignancies in Children?

Background: Alterations in the tumor suppressor gene TP53 have been associated with poor outcome in adult hematological malignancies. We have earlier reported an increased expression of the TP53 encoded protein p53, in bone marrow samples from pediatric patients with aggressive leukemia. Our aim was now to evaluate p53 protein expression at different time points before and after hematopoietic stem cell transplantation (HSCT) as a predictor of relapse in a group of children diagnosed with MDS, JMML and CML, and also investigate if potential alterations in expression could be correlated to mutations in TP53. Procedure: Paraffin embedded bone marrow samples from 33 pediatric patients diagnosed with MDS, JMML and CML between 1997 and 2010 were collected retrospectively from time of diagnosis and pre and post HSCT. Immunohistochemistry (IHC) was performed on tissue microarrays (TMA) with antibodies to p53 and p21. DNA sequencing of exon 2–11 of TP53 was performed in 7 patients with JMML and 5 patients with MDS. Results: Elevated p53 protein expression at diagnosis predicted for relapse, odds ratio (OR) 1.19 (95% CI: 1.02–1.40, p = .028). Sequencing of TP53 did not reveal any mutations in the 12 patients analyzed and p53 expression correlated positively to p21 expression indicating a functional p53/p21 protein pathway. Conclusion: Elevated p53 protein expression at diagnosis may be an indicator of relapse in children with MDS, JMML and CML.     

Autologous bone marrow transplantation in children with acute lymphoblastic leukemia

We report 25 children with acute lymphoblastic leukemia (ALL) treated with purged autologous bone marrow transplantation (ABMT) at a single center. Two children with high-risk ALL were transplanted in first remission and 23 with relapsing ALL were transplanted in second (n = 21) or third (n = 2) remission. There was no procedure-related mortality. The median time to engraftment (i.e. to reach a polymorphonuclear cell count of 0.5 x 10(9)/l) was 25 days (range 16-45 days). Seven children relapsed, four within five months after ABMT: 18 of 25 children (72%) are in continuous complete remission after a median follow-up period of 50 months (range 5-71 months). The predicted long-term disease-free survival is 65% in the whole group and 61% in those transplanted after relapse. Relapse-free children returned to normal activities within three months after ABMT. The major side effects were development of cataract and gonadal insufficiency. We consider the results promising, but our data do not allow comparison with results reported from treatment with chemotherapy alone, since some of our patients were referred from other centers and represent a selected patient group. Long-term follow-up of well-defined patient populations is necessary to evaluate the effect of ABMT.     

Allogeneic bone marrow transplantation in juvenile myelomonocytic leukemia without total body irradiation

Allogeneic bone marrow transplantation (BMT) without a total body irradiation (TBI) conditioning regimen was investigated in children with juvenile myelomonocytic leukemia (JMML). Eight consecutive patients with JMML (n = 6) or monosomy 7 (n = 2) underwent BMT at a median age of 20 months. Donor source included fully matched related (n = 3), mismatched related (n = 2), or fully matched unrelated (n = 3). The conditioning regimen included busulfan, cyclophosphamide, and etoposide (VP16) (melphalan was substituted for VP16 in one patient). The first patient in the series underwent TBI. Graft-versus-host disease prophylaxis was with cyclosporin and methotrexate and in vivo T-cell depletion (Campath 1 g) for mismatched and unrelated transplants. Seven and two patients, respectively, received chemotherapy and splenectomy before BMT. At a median follow-up of 48 months after BMT, five patients remained in remission. The overall survival rate was 63% at 5 years. All deaths occurred in patients with refractory disease at the time of BMT. Allogeneic BMT without TBI appears to be effective therapy for JMML and avoids some of the potential late sequelae of TBI in preschool children.     

Juvenile myelomonocytic leukemia in a 16-year-old with noonan syndrome: case report

A 16-year-old man with splenomegaly presented with ascites and bilateral leg eschars. Although he had intermittently elevated absolute monocyte counts, a diagnosis of juvenile myelomonocytic leukemia (JMML) was discounted because of his age and lack of persistent leukocytosis. Detailed examination demonstrated features consistent with Noonan syndrome (NS), including typical facies, growth retardation, a cardiac defect, and a history of a coagulopathy. He underwent a splenectomy where the surgeons encountered a rind of tissue composed of monocytes encasing the abdominal organs. After splenectomy, his leukocytes rose to over 100×10/L with a monocytosis, suggesting JMML. On the basis of the clinical suspicion of NS, mutation analysis revealed a KRAS mutation, which is known to be common to both NS and JMML. Clinicians should have high index of suspicion for JMML in patients with Noonan features, regardless of a patient's age.     

Early diagnosis of severe combined immunodeficiency syndrome.

Infants with severe combined immunodeficiency syndrome (SCIDS) have a greatly improved prognosis if diagnosed and treated before they develop overwhelming infection. Clinical and laboratory data on 45 patients with SCIDS were retrospectively reviewed to assess the value of absolute lymphocyte counts in making an early diagnosis. Ninety infants matched for age, sex, and presenting symptoms were used as controls. Thirteen (29%) infants with SCIDS were diagnosed at birth as previous siblings had been affected; 32 (71%) were diagnosed after the development of symptoms. Eighteen (56%) of these remained undiagnosed until after 6 months of age. The first symptoms occurred at a median of 5 weeks (range 1 day to 8 months) and the first admission to hospital was at 4 months (range 1 week to 16 months). Symptoms included respiratory infection (91%), vomiting and diarrhoea (81%), failure to thrive (88%), candidiasis (50%), and skin lesions (28%). The mean lymphocyte count was 1.71 x 10(9)/l compared with 7.2 x 10(9)/l in controls. Excluding one child with Omenn's syndrome (lymphocyte count 23.3 x 10(9)/l, all symptomatic infants with SCIDS had lymphocyte counts less than 2.8 x 10(9)/l at presentation. The median delay between the first abnormal lymphocyte count and diagnosis was seven weeks (range one day to 13 months). Twenty eight (88%) of 32 infants would have been diagnosed before 6 months of age if investigated after the first low lymphocyte count. These data indicate that low lymphocyte counts are predictive of SCIDS. Paediatricians are urged to pay attention to the absolute lymphocyte counts in all infants in whom a full blood count is performed. Those with lymphocyte counts persistently less than 2.8 x 10(9)l should be investigated for SCIDS.