Naphthalene biomarkers and relationship with hemoglobin and hematocrit in White, Black, and Hispanic adults: results from the 2003-2004 National Health and Nutrition Examination Survey.

Naphthalene is an important contaminant in indoor and outdoor air. Acute overexposure can have toxic effects, resulting in hemolysis. There have been no studies evaluating the impact of environmental exposure on red blood cell indices. We examined 1- and 2-hydroxynaphthalene urinary metabolites (NAP1 and NAP2) in non-Hispanic White, non-Hispanic Black, and Mexican-American adults in the USA and their relationship with hemoglobin (Hb) and hematocrit (HCT). Using the 2003-2004 National Health and Nutrition Examination Survey data, weighted generalized linear regression analyses were used to examine the association between Hb (in grams per deciliter) and HCT (in percent) with NAP1 and NAP2 (per 100,000 ng/L). Beta coefficients ± SE are reported. NAP1 and NAP2 were highest in non-Hispanic Blacks, followed by non-Hispanic Whites, and lowest in Mexican-American adults. There was a positive association between NAP1 and Hb (0.39 ± 0.11, p = 0.0034) and HCT (1.14 ± 0.28, p = 0.0009) after adjusting for age, gender, race, education, and smoking. Stratified analysis by smoking showed similar results with the association being stronger for smokers (Hb 0.63 ± 0.23, p = 0.02; HCT 1.43 ± 0.79, p = 0.09) than nonsmokers (Hb 0.34 ± 0.14, p = 0.03; HCT 1.08 ± 0.42, p = 0.02). The association was also stronger for non-Hispanic blacks (Hb 0.54 ± 0.20, p = 0.02; HCT 1.43 ± 0.55, p = 0.02) than for non-Hispanic whites (Hb 0.37 ± 0.18, p = 0.06; HCT 1.20 ± 0.51, p = 0.03) and was not significant for Mexican-Americans (Hb 0.30 ± 1.7, p = 0.10; HCT 0.99 ± 0.52, p = 0.08). NAP2 was not significantly associated with Hb or HCT. The observed disparity in NAP1 and NAP2 levels by race/ethnicity is consistent with published literature. The origin of these differences in exposure is unclear but may reflect differences in environmental exposure as well as genetic susceptibility. The positive association between NAP1 with HCT and Hb is an unexpected finding. Further research is needed to understand the possible biological mechanisms or other explanations for this association.

Muscle cell injury, haemolysis and dark urine in children with falciparum malaria in Papua New Guinea.

During a prospective study of red cell variants and severe malaria in children, a surprising observation was the occurrence of dark urine. Children were grouped according to urine findings: 22 had dark urine that contained a haem protein (Group I), 93 had urine of normal colour that contained a haem protein (Group II) and 236 had normal urine (Group III). To investigate the cause of dark urine, haemolysis and muscle cell injury were assessed. Intravascular haemolysis was greater in Group I than in Groups II and III. However, anaemia was more severe in Group III and is likely to have resulted mainly from extravascular haemolysis. Median plasma myoglobin concentrations were greater in Groups I and II than Group III (P = 0.00060). Plasma myoglobin was greater in children with cerebral malaria, hyperlactataemia and those who died but was not associated with acidosis. Urine myoglobin was greater in Group I than Groups II and III (P = 0.00054). It is likely that both haemoglobin and myoglobin contributed to dark urine. The association between muscle cell injury and coma suggests sequestration of parasitized red cells as a common underlying pathology. In malaria, hyperlactataemia may result directly from breakdown of muscle protein as well as tissue hypoxia.

Delayed hemolytic transfusion reaction/hyperhemolysis syndrome in children with sickle cell disease.

OBJECTIVE: Alloimmunization in patients with sickle cell disease (SCD) has a reported incidence of 5% to 36%. One complication of alloimmunization is delayed hemolytic transfusion reaction/hyperhemolysis (DHTR/H) syndrome, which has a reported incidence of 11%. In patients with SCD, clinical findings in DHTR/H syndrome occur approximately 1 week after the red blood cell (RBC) transfusion and include the onset of increased hemolysis associated with pain and profound anemia. The hemoglobin (Hb) often drops below pretransfusion levels. In many reported adult cases, the direct antiglobulin test (DAT) remains negative and no new alloantibody is detected as the cause for these transfusion reactions. To date, few pediatric cases have been reported with this phenomenon. The objective of this study was to describe the clinical and laboratory findings of a case series in children who had SCD and experienced a DHTR/H syndrome at our institution. METHODS: An 11-year retrospective chart review of patients with discharge diagnosis of SCD and transfusion reaction was performed. DHTR/H syndrome was defined as the abrupt onset of signs and symptoms of accelerated hemolysis evidenced by an unexplained fall in Hb, elevated lactic dehydrogenase, elevated bilirubin above baseline, and hemoglobinuria, all occurring between 4 and 10 days after an RBC transfusion. Patient characteristics, time from transfusion, symptoms, reported DAT, new autoantibody or alloantibody formation, laboratory abnormalities, and complications were recorded. Patients with acute transfusion reactions were excluded. RESULTS: We encountered 7 patients who developed 9 episodes of DHTR/H syndrome occurring 6 to 10 days after RBC transfusion. Each presented with fever and hemoglobinuria. All but 1 patient experienced pain initially ascribed to vaso-occlusive crisis. The DAT was positive in only 2 of the 9 episodes. The presenting Hb was lower than pretransfusion levels in 8 of the 9 events. Severe complications were observed after the onset of DHTR/H: acute chest syndrome, n = 3; pancreatitis, n = 1; congestive heart failure, n = 1; and acute renal failure, n = 1. CONCLUSIONS: DHTR/H syndrome occurs in pediatric SCD patients, typically 1 week posttransfusion, and presents with back, leg, or abdominal pain; fever; and hemoglobinuria that may mimic pain crisis. Hb is often lower than it was at the time of original transfusion, suggesting the hemolysis of the patient's own RBCs in addition to hemolysis of the transfused RBCs; a negative DAT and reticulocytopenia are often present. Severe complications including acute chest syndrome, congestive heart failure, pancreatitis, and acute renal failure were associated with DHTR/H syndrome in our patients. DHTR/H in the pediatric sickle cell population is a serious and potentially life-threatening complication of RBC transfusion. It is important to avoid additional transfusions in these patients, if possible, because these may exacerbate the hemolysis and worsen the degree of anemia. DHTR/H syndrome must be included in the differential of a patient who has SCD and vaso-occlusive crisis who has recently had a transfusion.

Severe hemoglobinuria masquerading as gross hematuria following mitral valve replacement.

Gross hemoglobinuria following mitral valve replacement can represent a rare form of hemolytic anemia. This condition can masquerade as gross hematuria in the post-valve replacement patient. It is commonly associated with valvular dysfunction, specifically, perivalvular leakage. The leakage may not be apparent on routine echocardiography but it may be documented with trans-esophageal echocardiography.

Pattern of iron excretion in relation to haemoglobin level and iron load in 8 haematological patients following the administration of subcutaneous deferrioxamine.

Iron excretion following subcutaneous administration of deferrioxamine (DFO) was measured between two transfusions of packed red cells in 6 patients with beta-thalassaemia major on the high level Hb transfusion regime; and in a single 3-day period in 2 other patients, 1 with transfused beta-thalassaemia major and the other with haemolytic anaemia due to PK deficiency. The pattern of iron excretion did not change significantly during the period between the two transfusions and was found to be related to serum ferritin levels. The proportion of iron excreted in the stools was inversely related to the serum ferritin level. These observations on iron excretion are of practical importance in relation to DFO administration, especially when evaluated in thalassaemics with normal haemoglobin levels and low iron stores.

Urinary neopterine in the assessment of lymphoid and myeloid neoplasia, and neopterine levels in haemolytic anaemia and benign monoclonal gammopathy.

The urinary neopterine levels were measured by HPLC in 417 normal subjects and in 216 patients with haematological diseases. All patients with active malignancies (multiple myeloma, polycythaemia vera. Hodgkin's lymphoma, non-Hodgkin's lymphoma, chronic myelocytic and chronic lymphocytic leukaemia) showed highly elevated mean and median values compared to the control groups. Those of patients with multiple myeloma stage I were only raised to near the upper limit of healthy subjects. Of 123 patients with active disease 105 (85%) were above the upper limit. In contrast, the mean and median values of 56 patients with neoplasias in remission (Hodgkin's and non-Hodgkin's lymphoma, acute leukemia and multiple myeloma) were not different from those of healthy subjects, and only 7 (12.5%) of these patients had levels above the upper limit. In patients with non-malignant diseases (haemolytic anaemia and benign monoclonal paraproteinaemia) the mean and median values were not raised. In patients with non-Hodgkin's lymphoma and with chronic lymphocytic leukemia, the neopterine levels corresponded with the tumor stage. The present data suggest tht neopterine assay may supplement laboratory measurements in haematological diseases, providing helpful information.

The clinical significance of ferritinuria.

Urinary ferritin levels were measured by a "2-site" immunoradiometric assay in normal volunteers and in patients with various hematologic disorders. The mean urinary ferritin concentration in normal subjects averaged 2.2 microgram/liter, only 3% of the serum ferritin level. Elevated urinary ferritin levels averaging 45 microgram/liter were observed in patients with hematologic malignancies, but there was a proportional increase in serum ferritin so that the urinary level still averaged only 7% of the serum value. The highest urinary ferritin values (mean 170 microgram/liter) were associated with chronic hemolytic anemia, and in these patients, urinary ferritin rose disproportionately in relation to the serum, averaging 82% of it. This higher urinary level apparently reflects increased ferritin in renal tubular cells due to glomerular filtration of unbound hemoglobin, a mechanism that is supported by a highly significant correlation between urinary ferritin and serum haptoglobin levels. In normal subjects and in patients with malignancy, the source of urinary ferritin appears different, since a highly significant correlation was observed between urinary ferritin and reticuloendothelial iron stores as measured by serum ferritin or total iron-binding capacity. In this setting, the most likely source of urinary ferritin is the iron contained in renal tubular cells, which is apparently in equilibrium with body iron stores.

Urinary ferritin protein in subjects with prosthetic heart valves and other disorders.

Twenty-four-hour urine ferritin protein excretion (UFPE) was elevated in the great majority of patients with prosthetic cardiac valves. In this group, there was a positive correlation with the presence of haemosiderin in the urine and with another indirect measure of reduced red-cell survival, namely, serum lactic dehydrogenase. In a number of hospital patients with various disorders, UFPE was also increased. In this latter group, however, there was no constant accompanying haemosiderinuria or elevation of lactic dehydrogenase. The measurement of UFPE can be added to the list of screening tests for intravascular haemolysis, but analysis of the different isoferritins in urine is necessary to fully understand the mechanism of excretion in the different groups.