Reticulocytes in untreated Obstructive Sleep Apnoea

Abstract

Background and Aim. The short, repetitive hypoxaemic episodes observed in obstructive sleep apnoea (OSA) may determine small augmentations in mature red blood cells. It is unknown whether they affect reticulocyte release. This study explored whether the number and degree of maturation of circulating reticulocytes may be altered in OSA, possibly through the effect of erythropoietin. Methods. Fifty male adult patients with suspected OSA, normoxic during wakefulness, were studied. After nocturnal polysomnography, a blood sample was withdrawn for blood cells count, erythropoietin, iron and transferrin determination. Reticulocyte concentration and degree of immaturity [high (H), medium (M), or low (L)] were also determined. Immature reticulocyte fraction (IRF) was calculated as (M+H) percentage of reticulocytes. Results. A wide range of OSA severity was found [apnoea/ hypopnoea index (AHI): 44.3±30.4, range 0.3-105; sleep time spent at oxyhaemoglobin saturation 2% had higher EPO levels (p<0.05), but not worse nocturnal desaturations, than those with values <2%. By contrast, subjects with IRF <15% showed worse desaturations (p<0.05), but similar EPO concentrations, when compared to subjects whose IRF was <10%. At univariate analysis, reticulocyte count correlated to erythropoietin, while IRF to transferrin saturation, BMI and OSA severity. At multiple regression, only lowest nocturnal oxygen saturation remained a significant contributor to IRF (r2 0.223, p<0.05). Conclusions. This data suggests that hypoxaemia due to OSA could influence the release of immature reticulocytes, but this effect is not mediated by erythropoietin.

Differences in selected blood parameters between brachycephalic and non-brachycephalic dogs

“…Still, the modest increase in reticulocyte count ( Figure 1B ) and a higher abundance of MFI reticulocytes ( Figure 1C ) may be indicative of stress erythropoiesis. These features were also reported for patients with OSA, for whom a strong association between the higher abundance of immature reticulocytes with duration of hypoxic phases during sleep was shown ( 67 ). Marrone et al ( 67 ) reported that abundance of MFI reticulocytes shows maximal association with the apnea/hypopnea index, and with the lowest arterial O 2 saturation, while the HFI reticulocyte counts do not correlate with these parameters.…”

“…These features were also reported for patients with OSA, for whom a strong association between the higher abundance of immature reticulocytes with duration of hypoxic phases during sleep was shown (67). Marrone et al (67) reported that abundance of MFI reticulocytes shows maximal association with the apnea/hypopnea index, and with the lowest arterial O 2 saturation, while the HFI reticulocyte counts do not correlate with these parameters. In human subjects with OSA, reduction in reticulocyte maturation was not accompanied by an increase in plasma erythropoietin levels.…”

Sleep Apnea Screening in Children With Sickle Cell Anemia

“…Hypoxemia, as a result of OSA or anemia, could influence the release of reticulocytes in SCA. 16 Lower hemoglobin level and reticulocytosis suggests SCA severity predisposes to habitual snoring, potentially because of a greater degree of upper airway anatomical adaptation. Tonsillar size and Malampatti score are risk factors for habitual snoring in children with SCA, but many of the previously recognized risk factors in otherwise healthy children were not observed such as age, sex, obesity, asthma, allergic rhinitis, atopy, and environmental tobacco smoke exposure.…”

“…A higher positive PSQ rate in the snoring group suggests heavier sleep-disordered breathing burden. Hypoxemia, as a result of OSA or anemia, could influence the release of reticulocytes in SCA 16. Lower hemoglobin level and reticulocytosis suggests SCA severity predisposes to habitual snoring, potentially because of a greater degree of upper airway anatomical adaptation.…”