Characterization of S-glutathionyl hemoglobin in homozygous sickle cell disease.

S-glutathionyl hemoglobin is a proposed biomarker of oxidative stress but has not been measured in sickle cell disease patients. Unlike the S-glutathionyl adduct of normal adult hemoglobin, S-glutathionyl sickle hemoglobin (HbSSG) cannot be directly measured by capillary isoelectric focusing, because it coelutes with fetal hemoglobin (HbF). This suggests that HbF, measured in sickle cell patients with or without hydroxyurea therapy, might contain endogenous HbSSG. As S-glutathionyl hemoglobin can form during sample storage, HbSSG could falsely elevate HbF levels in stored samples. We measured HbSSG based on the quantitative difference in the heterogeneous HbF/HbSSG peak before and after hemolysates were treated with dithiothreitol. Paired t tests showed that dithiothreitol reduced HbF/HbSSG in blood from pediatric sickle cell patients (n=25, mean decrease+/-SD=1.0%+/-0.6, P<0.05) but not in normal infants (n=25). Higher HbF levels in hydroxyurea-treated patients (n=5) were not attributable to HbSSG. HbSSG increased significantly within 1 day in samples stored at -20 degrees C but was unchanged in samples stored 60 days at-70 degrees C. We conclude that blood from sickle cell patients contained up to 2.2% HbSSG, and that endogenous HbSSG is a minor interferent in the measurement of HbF in fresh blood but a major interferent in improperly stored samples.

Pediatric Hodgkin's and non-Hodgkin's lymphomas: a retrospective analysis at the Children's Hospital of New Orleans.

Lymphomas constitute 10-12% of childhood cancers and are the third most common childhood malignancy. A retrospective analysis of thirty-six patients from the tumor registry of Children's Hospital of New Orleans was conducted during the period from 1995-2000. Patients were divided based on patient and tumor characteristics with recurrence and survival data compared to the Surveillance, Epidemiology and End Results (SEER) data of the National Cancer Institute. There were 18 patients (51%) with Non-Hodgkin's Lymphoma (NHL) and 17 (49%) with Hodgkin's disease (HD). Our sample had a similar distribution compared to the national population cohort except for different gender distribution in our HD patients. Also, most of our patients (63%) presented with advanced disease (Stages III and IV). Seventeen percent had recurrence of disease and 80% achieved remission, of which two patients developed secondary leukemia. Overall mortality was 17%. The survival in patients with HD was 94% which is comparable if not slightly superior to the national data. In patients with NHL, survival was 72% which was marginally lower than the national results (80%), most likely due to more advanced disease. Increased awareness in the pediatric community of the signs and symptoms of childhood lymphoma should result in earlier diagnosis and improved survival.

Advanced glycation end-products in sickle cell anaemia.

Tissue accumulation of advanced glycation end-products (AGEs) has been implicated in the oxidant-induced vascular pathology of diabetes and other diseases. Because homozygous sickle cell anaemia (SCA) is a state of oxidative stress, we tested the hypothesis that circulating AGE levels are elevated in SCA. Blood was obtained from age- and race-matched children classified as either non-sickle cell controls, SCA without vaso-occlusive crisis (SCA - VOC), or SCA with vaso-occlusive crisis (SCA + VOC). Plasma and red blood cell (RBC) AGE levels were measured by immunoassay. RBC levels of reduced (GSH) and oxidized (GSSG) glutathione were measured by capillary electrophoresis as an indicator of endogenous antioxidant status. The results showed that plasma AGE levels and the rate of RBC AGE accumulation were significantly higher in patients with SCA compared with controls. GSH was not different between groups but was significantly inversely correlated with plasma AGEs in both controls and patients with SCA. GSSG was significantly lower and GSH/GSSG higher in SCA + VOC patients, suggesting that GSH/GSSG might be an objective indicator of acute VOC or a risk factor for VOC. We conclude that circulating AGE levels are strongly influenced by endogenous antioxidant status and may play a role in the vascular pathology of SCA.

Diagnosis and characterization of Hb C/Hb Iowa: a rare but easily misidentified compound heterozygous condition.

Hb Iowa is a rare hemoglobin (Hb) variant with a Gly --> Ala substitution at position 119 of beta-globin. It was previously reported only in an African American infant who was also heterozygous for Hb S [beta6(A3)Glu --> Val] and her mother (Hb A/Iowa). Here we describe the second report of Hb Iowa, the first in conjunction with Hb C [beta6(A3)Glu --> Lys]. The patient was an African American girl, originally diagnosed as homozygous Hb C during neonatal screening. When seen in our clinic, hematological data for both the child and her mother (Hb C trait) indicated mild anemia with slightly low mean corpuscular volume (MCV) but normal red blood cell (RBC) count. Analysis of blood from the child by capillary isoelectric focusing (cIEF) identified Hb C and an unknown Hb variant with an isoelectric point (pI) intermediate to that of Hbs F and A. The unknown variant was identified as Hb Iowa by DNA sequence analysis of the beta-globin gene (GGC --> GCC). Both reported cases of Hb Iowa indicated that there are no abnormal hematological manifestations associated with this rare Hb variant. In both cases, however, Hb Iowa was mistaken for Hb F during routine neonatal screening by high performance liquid chromatography (HPLC) and/or gel IEF. Neonatal misidentification of Hb Iowa led to misdiagnosis of sickle cell disease and Hb C disease, respectively. In our patient, Hb Iowa was also misidentified as Hb A at 2 years of age by a commercial reference laboratory using cellulose acetate and citrate agar gel electrophoresis. This led to an incorrect diagnosis of Hb C trait. These results show that commonly used analytical methods can easily misidentify Hb Iowa as Hbs F or A in neonates, or older individuals, resulting in incorrect identification of the Hb phenotype. We conclude that the presence of Hb Iowa, or other variants with similar pIs, should be considered in cases where the results of follow-up testing conflict with neonatal diagnosis of sickle cell or Hb C disease, or where clinical presentation does not agree with diagnosis of either homozygous or heterozygous Hb S or Hb C.

Benign multilocular cystic nephroma.

This article reports a case of cystic nephroma to bring awareness about the benign nature of this condition. The patient presented with a painless abdominal mass. Computed tomography showed a homogeneous, multicystic tumor of the superolateral portion of the left kidney with thin septa without solid parts. Histology confirmed the diagnosis of cystic nephroma.

Passive active prophylaxis against Hepatitis B in children with acute lymphoblastic leukemia.

The aim of this study was to assess the antibody response to combined passive active immunisation versus active immunisation along with interferon against Hepatitis B in 60 patients with acute lymphoblastic leukemia (ALL) between 1 and 21 years of age with negative Hepatitis B virus (HBV) serology at presentation. Thirty-one patients received combined passive active immunisation with human specific Hepatitis B immunoglobulin (HEPABIG-VHB Pharmaceuticals) and Hepatitis B vaccine (arm I) and 29 patients received active immunisation along with interferon (arm II). Protective antibody levels were detected in 89.6 and 21% patients, respectively, at the 6-month evaluation. Infection with HBV occurred in 17 and 59% patients, respectively, at the 6-month evaluation. Interferon, thus, failed to serve the role as a vaccine adjuvant. At the 9-month evaluation of patients who received immunoglobulin, protective antibody titers were lost in 8 out of 19 evaluable patients (42%) and of these, 3 patients became HBsAg reactive at this point of time. This study indicated that 47.3% patients undergoing aggressive chemotherapy responded to combined passive active prophylaxis with protective titers of antiHBs at the 9-month evaluation. However, the rate of HBV infection was greatly reduced to 27%. We suggest that usage of passive immunisation in the aggressive phase, followed by active immunisation after cessation of intense chemotherapy would be a better option to increase the rates of protective antibody levels in these immunocompromised patients with leukemia.

Leukemia in infants.

OBJECTIVE: Acute Leukemia is rare in infants. It is characterized by non-specific symptomatology requiring a high index of suspicion on the part of a pediatrician for referral and diagnosis. It has peculiar biological features, unresponsiveness to treatment and poor prognosis. METHODS: Eighteen infants with acute leukemia were seen during 1994 to 2001 and were analyzed on the basis of clinical and laboratory data. There were 13 cases of Acute Lymphoblastic Leukemia (ALL), 4 cases of Acute Myeloid Leukemia (AML) and one case remained unclassifiable, as the surface markers could not be done. Morphologically 9/13 cases of ALL were of FAB L1 type and remaining of L2 subtype, and 2/4 cases of AML were of FAB M1 type and remaining of M2 subtype. RESULT: Clinical data was available completely only in 11 cases. Hyperleucocytosis was present in 4 cases, organomegaly in 8 cases and lympadenopathy in 5 cases. One patient presented with a chloroma in the retrorbital region although there was no parenchymal involvement of the brain. Immunophenotyping could be done in 13 cases, where 7 cases were diagnosed as CALLA positive-ALL (HLADR+, CD19+, CD10+), 2 cases as Early Pre-B ALL (HLADR+, CD19+, CD10 negative), one as T ALL (cCD3+, CD2+, CD7+) and 3 cases as AML (CD13+, CD33+, HLADR+). None of our patients received treatment.