Erythrocyte filterability and heme catabolism during the menstrual cycle

Removal of the influence of plasma volume fluctuations for the athlete biological passport and stability of haematological variables in active women taking oral contraception

The haematological module of the athlete biological passport (ABP) monitors longitudinal haematological variations that could be indicative of blood manipulation. This study applied a multi‐parametric model previously validated in elite cyclists to compare inferred and actual PV variations, whereas the potential influence of the oral contraceptive pill (OCP) cycle on the ABP blood biomarkers and plasma volume (PV) in 14 physically active women taking OCPs was also investigated. Blood and serum samples were collected each week for 8 weeks, and the ABP haematological variables were determined according to the World Anti‐Doping Agency guidelines. Transferrin (sTFN), ferritin (FERR), albumin (ALB), calcium (Ca), creatinine (CRE), total protein (TP) and low‐density lipoprotein (LDL) were additionally computed as ‘volume‐sensitive’ variables in a multivariate analysis to determine individual estimations of PV variations. Actual PV variations were indirectly measured using a validated carbon monoxide rebreathing method. We hypothesised ABP markers to be stable during a standard OCP cycle and estimated PV variations similar to measured PV variations. Measured PV variations were in good agreement with the predictions and allowed to explain an atypical passport finding (ATPF). The ABP biomarkers, Hbmass and PV were stable over 8 weeks. Significant differences occurred only between Week 7 and Week 1, with lower levels of haemoglobin concentration ([Hb]), haematocrit (HCT) and red blood cell count (RBC)(−4.4%, p < 0.01; −5.1%, p < 0.01; −5.2%, p < 0.01) and higher levels of PV at week 7 (+9%, p = 0.05). We thus concluded that estimating PV variations may help interpret individual ABP haematological profiles in women.

Endogenous carbon monoxide production in disease

Carbon monoxide (CO) in tissues and cells can originate from inhalation of CO or endogenously. Endogenous production, carboxyhemoglobin (COHb) formation, and exhaled CO levels are influenced by physiological factors, including disease. It is suggested that endogenous CO production can be used as a biomarker for oxidative and inflammatory processes. Also, endogenous CO can contribute to increased body burden of CO, which may both disrupt normal CO signaling cascades and increase the risk of CO toxicity.

The menstrual cycle and Raynaud's phenomenon

Fluctuations in female sex hormones may be responsible for the high prevalence of Raynaud's phenomenon (RP) observed in premenopausal women. These hormones are known to act on central and peripheral thermoreceptors. In an attempt to establish whether cold sensitivity is altered during the menstrual cycle 50 premenopausal women were investigated. Of these, 26 had primary RP and 24 acted as controls. Each subject was exposed to environmental heating and cooling at three stages of the menstrual cycle to coincide with peaks and troughs in hormone levels. These stages were menstruation, periovulation, and during the midluteal phase. Finger hemodynamics was assessed by means of venous occlusion strain gauge plethysmography and fingertip temperature. Core temperature was assessed with an oral thermocouple. The results show that cold sensitivity was altered during the menstrual cycle in both groups with the fastest finger rewarming pattern during menstruation. Moreover, a significant difference was observed in core temperature between the two groups during the midluteal phase. As a group, subjects with RP failed to show a significant rise in core temperature following ovulation. The authors conclude that the menstrual cycle is associated with changes in the effect of cold on digital blood flow.

Anaemia in patients with solid tumours and the role of erythrocyte deformability

The deformability of erythrocytes, which is a factor of utmost importance both for capillary perfusion and for determining erythrocyte life span, has been studied in patients with solid tumours and in healthy subjects. Deformability was significantly decreased in all patients, especially those with anaemia. In this latter group of patients, carboxyhaemoglobin saturation of blood (COHb), reflecting erythrocyte haemoglobin breakdown, was also significantly increased, and this increase was closely correlated with the degree of impaired deformability of the erythrocytes. In the group of patients without anaemia, where erythrocyte deformability was also impaired, no such correlation was found. In 4 patients with Hodgkin's disease and fever as part of B symptoms, erythrocyte deformability decreased during fever and returned to normal when fever subsided. In 2 of these patients the administration of a prostaglandin-synthesis inhibitor (indomethacin) evoked a deformability, which was even better than during periods without fever. Since fever in Hodgkin patients with B symptoms has been attributed to the production of prostaglandins, these results may suggest a relationship between prostaglandin production and erythrocyte deformability in patients with malignant tumours. The close correlation between the degree of decrease in erythrocyte deformability and COHb levels in the patients with anaemia might indicate a role for prostaglandins in the production of anaemia of malignancy.

Effect of total leucocyte count on whole blood filterability in patients with peripheral vascular disease

An abnormal filterability of whole blood through micropore membranes in vitro has been reported in peripheral vascular disease and has been thought to indicate abnormal red cell deformability. Blood from 68 patients with symptomatic peripheral vascular disease of varying severity and from 32 age-matched controls without a history of peripheral vascular disease was studied by the technique of whole blood filtration. In agreement with earlier findings, whole blood filterability was significantly reduced in patients with symptoms of vascular disease, but also their total leucocyte count was significantly higher than that of the controls. Variation in leucocyte count was found to affect significantly whole blood filterability, and the abnormal filterability in peripheral vascular disease could be entirely ascribed to this factor and not to an alteration in red cell deformability. The raised leucocyte count was not due to smoking but its cause could not be explained.

Altered haemorheology in oral-contraceptive users

The haemorheological profile of the menstrual cycle was determined in 12 women who did not take oral contraceptives and compared with that in two groups of women (n = 8 and n = 30) who had been taking oral contraceptives for at last six months. Packed cell volume, platelet count, erythrocyte deformability, plasma fibrinogen concentration, and plasma and whole-blood viscosity varied cyclically throughout the menstrual cycle in the 12 non-users. This variation was abolished by the use of oral contraceptives, and the values of these indices were raised by an amount likely to predispose to thrombosis.

Heme catabolism in liver cirrhosis with portal hypertension after shunt surgery

Endogenous production of carbon monoxide (VCO), total and direct reacting serum bilirubin (TSB, DRB) were determined in 26 patients with liver cirrhosis and portal hypertension to evaluate the effect of various shunt operations on total heme catabolism. The material was divided into 3 groups. In group I, 11 patients not operated upon, mean VCO (+/- S.D.) was 18.4 +/- 6.0 micronmol/mmol total body heme per day (reference value 12.6 +/- 2.9). In group tii, 7 patients operated upon with subcutaneous transposition and a subtotal resection of the spleen, mean VCO (14.4 +/- 4.7) was not significantly raised. In group III, 8 patients operated upon with a modified distal splenorenal shunt, the highest mean VCO (26.1 +/- 9.0) was found. Mean TSB in the three groups was 34.8 +/- 29.2, 11.2 +/- 3.0, and 46.4 +/- 41.0 micronmol/l, respectively, and mean DRB 18.2 +/- 20.8, 3.7 +/- 1.0, and 26.8 +/- 34.1 micronmol/l, respectively. Estimated from preoperative laboratory values there was no difference in liver function between the three groups. The conclusion drawn is that heme catabolism, increased by 50% in liver cirrhosis complicated by portal hypertension probably due to a slight decrease in erythrocyte survival, tends to normalize after subcutaneous transposition and subtotal resection of the spleen. After spleno-renal shunting, on the other hand, a further increase in heme catabolism is seen. And so the increase in serum bilirubin often seen after the latter type of surgery is mainly related to a raised bilirubin production and not to a further decrease in liver function.