Sickle cell disease (SCD) is associated with a large spectrum of renal abnormalities, one of which, microalbuminuria/proteinuria (MA/P), is a known predictor of end-stage renal disease. We studied 90 children with SCD (57% male; mean age 11.4 +/- 5.2 years) to determine the prevalence and examine clinical correlates of MA/P. The average of two spot urine microalbumin-to-creatinine samples obtained 6 months apart was recorded. Medical records were reviewed for demographic and biochemical data. Medication use, resting office blood pressures (BP), vaso-occlusive pain crises (VOC), and monthly transfusions were recorded. Fourteen children (15.5%) had MA/P. Hemoglobin (Hb) levels were significantly lower in the children with MA than in those without MA/P (8.8 +/- 1.1 vs. 9.8 +/- 1.4 g/dL, respectively) and were significantly correlated with MA (rho = 0.24, p = 0.03). Children with MA were more likely to have abnormal BP (p = 0.058), with 5/14 being hypertensive or pre-hypertensive. In a multivariate logistic regression model of MA, both Hb and BP classification remained in the final model. MA is a simple screening biomarker of early kidney injury in children with SCD. Larger studies to evaluate predictive factors of MA and the relationship to BP are needed.

In our cohort of patients with SCD we observed a significant decrease in liver iron burden with high dose IV DFO. Our patients tolerated the therapy well without any major toxicity. This regimen is safe and may be an option for poorly compliant patients with significant iron overload.

Between 1995 and 2004, two NIH-sponsored studies (STOP/STOP II) showed that children with sickle cell disease (SCD) and abnormal transcranial Doppler blood flow measurements (high stroke risk) are protected from stroke with regular blood transfusions. Iron overload, which may lead to complications and requires iron removal therapy, was monitored by serum ferritin (SF). Liver iron concentration (LIC) measurement was not mandated by protocol and was performed at investigator discretion. Biopsy dates and lab values were captured during STOP/STOP II, providing an opportunity to validate SF against LIC. 75 LICs on 36 patients (19 female, 17 male) at 8 centers were obtained. No liver biopsy complications were reported. LICs were correlated with STOP/STOP II core laboratory SF and alanine aminotransferase (ALT) obtained within 180 days of LICs. Median age at first biopsy was 11.1 years (range, 4.5–17.8), median time from start of transfusion was 36 months (range, 2–100). Iron removal treatment was initiated a median 23 months (range, 4–108) from start of transfusion, with deferoxamine (n=27), and/or exchange transfusion (n=9). 21 pts (58%) had multiple LIC measures: 2 (n=9), 3 (n=8), 4 (n=2), 5 (n=2). Last LICs on iron removal therapy were obtained a median 72 months (range, 35–124) from start of transfusion. Correlation between SFs and LICs were r=-0.06 (n=18) for first LICs obtained prior to iron removal therapy, r=0.50 (n=17) for last LICs obtained on iron removal therapy, and r=0.51 for all LICs (n=60). Pts with single/last LIC >=15 mg/gram dry liver were significantly more likely to have ALTs >=45 IU/L compared to those with LICs <15 mg/gram (5/12 vs. 1/18; odds ratio 12.1; 95% CI 1.2–123.6; p=0.03). Pts with LIC >=15 mg/gram and ALT >=45 IU/L tended to have higher SFs then those with normal ALT (mean SF 4927 ng/ml, 95% CI 1739–8115 vs. mean SF 2255 ng/ml, 95% CI 1599–2912). 37% (7/19) of pts with LIC >=15 mg/gram had SFs <2000 ng/ml. 55% (11/20) of pts with repeated LICs, had last LICs <15 mg/gram after initiation of iron removal therapy. SF did not correlate with LICs after initiation of blood transfusion therapy and correlated weakly after initiation of iron removal therapy. Over 1/3 of children with evidence of significant iron overload, as measured by LICs, had low serum SFs (<2000 ng/ml), leading to a potentially erroneous interpretation of low iron stores. A significant portion of pts with elevated LICs had evidence of liver injury (ALT elevation). SF elevation observed in some pts may be due in part to end organ injury. Sustained iron overload control was achieved in over 1/2 of pts examined with repeated LICs.

Background: Factors influencing participation in clinical trials have been reported, but few studies analyze the combination of issues which affect overall patient accrual. When designing clinical trials, investigators are aware that some potential subjects may not be candidates for research participation and other subjects will decline. Total sample size is further affected by protocol-defined eligibility. BABY HUG (NCT00006400) is a randomized, double-blind, placebo-controlled Phase III clinical trial of hydroxyurea (HU), which had an enrollment goal of 200 infants, age 9–17 mo, with Hb SS or Sβ0-thalassemia. A number of screening tests (spleen scan, 99mTc-DTPA renal clearance, abdominal sonogram, transcranial Doppler ultrasound, neuropsychological testing, blood analyses) were required prior to study entry and at exit, with at least monthly follow-up visits during the 2-year study period. To enhance recruitment, an anonymized registry of potential subjects was created to identify factors affecting enrollment. Methods: BABY HUG study coordinators considered all infants with an FS/SS diagnosis on newborn screening who were less than age 17 mo. The coordinators developed an IRB-approved spreadsheet to record the number of potentially eligible subjects; whether parents were approached and, if not, why not; and reasons of those approached for participating or declining. Most of these reasons could be categorized into one of several common themes. Results: Of 1107 potential participants (23–132/center) identified between October 2003 and June 2007, 239 (22%) entered the screening process and 193 (17%) were randomized. More than 25% were not approached for various reasons, including poor adherence to standard clinical care or failing to meet eligibility criteria. Factors influencing enrollment decisions are shown in the figure. The willingness to contribute to medical knowledge, the hope of being randomized to receive the investigational drug (HU), and the desire for closer clinical care were the most common reasons for participating in BABY HUG. Conversely, fear of research, transportation problems, parental work schedules and the demanding nature of the study (with frequent blood samples and clinic visits) were the primary reasons for parents declining. Disease severity had less impact on decision-making, perhaps reflecting the often asymptomatic history of potential subjects. Conclusion: The time and effort required by multiple screening tests and frequent visits impact the willingness of eligible subjects to participate in a study. Similar trials may require a larger pool of potential participants than expected to meet accrual goals. Factors that influence subject availability and the decision-making process of participating families must be considered for successful recruitment. Figure Figure