The Coulter Counter Model S Plus--the shape of things to come

Digital assessment of peripheral blood and bone marrow aspirate smears

The diagnosis of benign and neoplastic hematologic disorders relies on analysis of peripheral blood and bone marrow aspirate smears. As demonstrated by the widespread laboratory adoption of hematology analyzers for automated assessment of peripheral blood, digital analysis of these samples provides many significant benefits compared to relying solely on manual review. Nonetheless, analogous instruments for digital bone marrow aspirate smear assessment have yet to be clinically implemented. In this review, we first provide a historical overview detailing the implementation of hematology analyzers for digital peripheral blood assessment in the clinical laboratory, including the improvements in accuracy, scope, and throughput of current instruments over prior generations. We also describe recent research in digital peripheral blood assessment, particularly in the development of advanced machine learning models that may soon be incorporated into commercial instruments. Next, we provide an overview of recent research in digital assessment of bone marrow aspirate smears and how these approaches could soon lead to development and clinical adoption of instrumentation for automated bone marrow aspirate smear analysis. Finally, we describe the relative advantages and provide our vision for the future of digital assessment of peripheral blood and bone marrow aspirate smears, including what improvements we can soon expect in the hematology laboratory.

Full-field hemocytometry. Forty years of progress seen through Clinical and Laboratory Hematology and the International Journal of Laboratory Hematology

The extraordinary advances in clinical hematology, biology, and oncology in the last decades would not have been possible without discovering how to identify and count the cells circulating in the blood. For centuries, scientists have used slides, counting chambers (hemocytometers), and diluting and staining solutions for this task. Then, automated hemocytometry began. This science, now linked to the daily routine of laboratory hematology, has completed an overwhelming path over a few decades. Our laboratories today operate with versatile multiparameter systems, ranging from complex single-channel instruments to bulky continuous flow machines. In terms of clinical information obtained from a simple routine blood test, the full exploitation of their potential depends on the operators' imagination and courage. A comprehensive review of the scientific publications that have accompanied the development of hemocytometry from the 1950s to today would require entire volumes. More than seven hundred contributions that authors worldwide have published in Clinical and Laboratory Haematology until 2007 and then the International Journal of Laboratory Hematology are summarized. Such journals have represented and hopefully will continue to represent the privileged place of welcome for future scientific research in hemocytometry. Improved technologies, attention to quality, new reagents and electronics, information technology, and scientist talent ensure a more profound and deeper knowledge of cell properties: current laboratory devices measure and count even minor immature or pathological cell subpopulations. Full-field hemocytometry includes the analysis of nonhematic fluids, digital adds to the microscope, and the development of effective point-of-care devices.

Toward a Blood-Borne Biomarker of Chronic Hypoxemia: Red Cell Distribution Width and Respiratory Disease

Hypoxemia (systemic oxygen desaturation) marks the presence, risk, and progression of many diseases. Episodic or nocturnal hypoxemia can be challenging to detect and quantify. A sensitive, specific, and convenient marker of recent oxygen desaturation represents an unmet medical need. Observations of acclimatization to high altitude in humans and animals reveals several proteosomic, ventilatory, and hematological responses to low oxygen tension. Of these, increased red cell distribution width (RDW) appears to have the longest persistence. Literature review and analyses of a 2M patient database across the full disease pathome revealed that increased RDW is predictive of poor outcome for certain diseases including many if not all hypoxigenic conditions. Comprehensive review of diseases impacting the respiratory axis show many are associated with increased RDW and no apparent counterexamples. The mechanism linking RDW to outcome is unknown. Conjectural roles for iron deficiency, inflammation, and oxidative stress have not been born out experimentally. Sports-doping studies show that erythropoietin (EPO) injection can induce formation of unusually large red blood cells (RBC) in sufficient numbers to increase RDW. Because endogenous EPO responds strongly to hypoxemia, this molecule could potentially mediate a long-lived RDW response to low oxygenation. RDW may be a guidepost signaling that unexploited information is embedded in subtle RBC variation. Applying modern techniques of measurement and analysis to certain RBC characteristics may yield a more specific and sensitive marker of chronic pulmonary and circulatory diseases, sleep apnea, and opioid inhibition of breathing.

Comparative analysis of human ex vivo-generated platelets vs megakaryocyte-generated platelets in mice: a cautionary tale

Thrombopoiesis is the process by which megakaryocytes release platelets that circulate as uniform small, disc-shaped anucleate cytoplasmic fragments with critical roles in hemostasis and related biology. The exact mechanism of thrombopoiesis and the maturation pathways of platelets released into the circulation remain incompletely understood. We showed that ex vivo-generated murine megakaryocytes infused into mice release platelets within the pulmonary vasculature. Here we now show that infused human megakaryocytes also release platelets within the lungs of recipient mice. In addition, we observed a population of platelet-like particles (PLPs) in the infusate, which include platelets released during ex vivo growth conditions. By comparing these 2 platelet populations to human donor platelets, we found marked differences: platelets derived from infused megakaryocytes closely resembled infused donor platelets in morphology, size, and function. On the other hand, the PLP was a mixture of nonplatelet cellular fragments and nonuniform-sized, preactivated platelets mostly lacking surface CD42b that were rapidly cleared by macrophages. These data raise a cautionary note for the clinical use of human platelets released under standard ex vivo conditions. In contrast, human platelets released by intrapulmonary-entrapped megakaryocytes appear more physiologic in nature and nearly comparable to donor platelets for clinical application.

Does mean platelet volume influence the attack or attack-free period in the patients with Familial Mediterranean fever?

Familial Mediterranean fever (FMF) is an autosomal recessive hereditary disease which is characterized by recurrent attacks of fever and peritonitis, pleuritis, arthritis, or erysipelas-like skin disease. Mean platelet volume (MPV) is a sign of platelet activation. There are limited studies in the literature about MPV levels in FMF patients. We aimed to investigate MPV levels during the attack period (group 1) and attack-free periods (group 2) in FMF patients, and to compare them with healthy controls (group 3). The study consisted of the data of: 60 group 1 patients, 120 group 2 patients, and 75 group 3 patients. Erythrocyte sedimentation rate, C-reactive protein, white blood cell count, platelet count, and MPV levels were retrospectively recorded from patient files. Statistical analyses showed that MPV was significantly lower in FMF patients both in group 1 and group 2 than in group 3 (p = 0.004, p = 0.002, respectively); however, there was no difference among group 1 and group 2 in patients with FMF (p = 0.279). The mean platelet count of group 1 was higher than that of group 3 (p = 0.010). In conclusion, this study results suggested that MPV level did not increase on the contrary, it decreased in patients with FMF both in group 1 and/or group 2 when compared to group 3. It was concluded that the lower MPV level was an expected result of secondary thrombocytosis in FMF patients.

An assessment of the Coulter Counter Models S Plus II and III

The Coulter Counter Models S Plus II and III have been evaluated. No serious safety hazards were identified. Scientific assessment showed some non-linearity in the Hb which caused the MCH and MCHC to vary as samples were diluted. Precision and carry-over were satisfactory. The results obtained compared well with those of the Coulter Counter Model S, except for WBC; reference methods showed better accuracy on the Models S Plus II and III. Platelet counts agreed with those by phase-contrast microscopy and the lymphocyte percentage was similar to that from the blood film except in the lymphoproliferative disorders. The whole blood and pre-dilute modes gave similar results though the platelet count was slightly higher in the whole blood mode. In the National External Quality Assessment Scheme results were in accordance with those from other Model S Plus Users. Time did not allow a detailed evaluation of the cell volume distribution curves but it was noted that the white cell profile was useful for detecting platelet aggregation. Efficiency assessment showed throughputs of 66 and 93 samples per hour on the Models S Plus II and III respectively. The platelet count was clinically useful as was the lymphocyte percentage measurement which rendered some differentials unnecessary. Rejection of the white cell profile was a helpful index of abnormality on the Model S Plus II but occurred non-specifically on the Model III tested.

Estrogen replacement therapy decreases platelet-activating factor-acetylhydrolase activity in post-menopausal women

OBJECTIVE

To examine the effects of estrogen replacement therapy on plasma platelet-activating factor-acetylhydrolase (PAF-AH) activity and the lipoprotein profile in post-menopausal women.

METHOD

Eight post-menopausal women received conjugated equine estrogen (0.625 mg/day) orally for a period of 10 weeks. PAF-AH activity and lipid levels were measured in plasma samples obtained from each subject prior to treatment and after 2, 6, and 10 weeks of estrogen therapy.

RESULTS

Within 2 weeks of initiating estrogen treatment, a significant reduction in PAF-AH activity (-26%) was observed. Estrogen also caused significant decreases in total cholesterol (-8%), low-density lipoprotein-cholesterol (-24%), and the ratio of apolipoprotein B to A-II (-19%). On the other hand, levels of both high-density lipoprotein-cholesterol (18%) and triglyceride (31%) were elevated.

CONCLUSION

Estrogen exerts a favorable effect on the lipoprotein profile, but decreased plasma PAF-AH activity may facilitate platelet aggregation thereby opposing protective effect of estrogen-replacement therapy with respect to thrombotic complications.

Treatment of aggressive non-Hodgkin's lymphoma in the elderly

A nonanthracycline-containing chemotherapeutic combination for the treatment of intermediate and high-grade non-Hodgkin's lymphoma was evaluated. Thirty-four consecutive and previously untreated patients, with a median age of 75 (range 54-86) years, with aggressive lymphoma, received daily etoposide (60 mg/m2 intravenous infusion [IVI]), cytosine arabinoside (50 mg/m2 subcutaneously), and methylprednisolone (60 mg/m2 IVI) on each of 5 consecutive days. Individuals with limited disease (stages I and II) (n = 9) received six, 3-day cycles of the same therapy and involved field radiation (36 Gy in 20 fractions) between the third and fourth courses. Patients with disseminated lymphoma (n = 25) received 10 cycles over 8 months of the same combination, with the addition of methotrexate (200 mg/m2 on days 8 and 15), followed by leucovorin rescue (10 mg/m2 orally every 6 hr for 8 doses). Of the 34 patients, 44% entered complete remission (CR), and 7 died before completing the first cycle of chemotherapy. Fifty-six percent of the patients with limited disease and 40% with disseminated lymphoma (P > 0.05) achieved CR. For all patients, median survival was 14 months (range 3 days- > 54 months), this being 12 and 15 months, respectively. For the entire population of responding patients, median survival has not been reached at a median follow-up of 39 months, while the median CR duration is 21 months. Ten of the 15 responders are alive in unmaintained CR at a median of 41 (range 30-54) months. Myelotoxicity was the major side effect, leading to adjustments in dose and schedule in two-thirds of the patients, although treatment changes did not affect outcome. Of the 15 deaths that occurred in this trial, in 53.3% it was unrelated to lymphoma or its therapy. Four patients that had achieved CR died of cardiovascular events (n = 2) or of progressive second malignancies (n = 2). It is concluded that cytosine arabinoside in combination regimens is effective in selected patients; this is particularly relevant in the elderly.

Platelet counting using plasma platelet concentrate samples

Platelet counting using samples of plasma from platelet concentrates prepared for transfusion was assessed. The methods employed included a manual phase-contrast method, and counting with Coulter S Plus and Sysmex E-2500 counters. All methods were reproducible (mean CV of 4.9, 2.2 and 1.4%, respectively). However, neat samples of platelet concentrates analysed by Coulter counter were inaccurate (mean count of 863.8 x 10(9)/l compared to 1018.9 x 10(9)/l counted manually). Moreover, the Coulter platelet counts were non-linear above 900 x 10(9)/l, whereas the E-2500 platelet counts were linear to 2700 x 10(9)/l. A one-in-three pre-dilution was required to obtain accurate, linear counts with the Coulter counter, whereas the E-2500 was accurate without pre-dilution (mean count of 1030.2 x 10(9)/l compared to 1018.9 x 10(9)/l counted manually). In conclusion, the method of platelet counting may affect true platelet yields.

Dietary iron deficiency and sports anaemia

In order to determine whether dietary inadequacies can explain the sub-optimal iron status widely documented in endurance-trained athletes, the food intake records of Fe-deficient and Fe-replete distance runners and non-exercising controls of both sexes were analysed. In all the male study groups the mean dietary Fe intake met the recommended dietary allowances (RDA; > 10 mg/d (US) Food and Nutrition Board, 1989). However, both female athletes and controls failed to meet the RDA with regard to Fe (< 15 mg/d) and folate (< 200 micrograms/d). There was no difference in the total Fe intakes of Fe-deficient and Fe-replete athletes and the controls of each sex. However, Fe-deficient male runners, but not female runners, consumed significantly less haem-Fe (P = 0.048) than their comparative groups. This suggests that the habitual consumption of Fe-poor diets is a factor in the aetiology of athletes' Fe deficiency.

The blood pressure response to infusions of angiotensin II during normal pregnancy: relation to plasma angiotensin II concentration, serum progesterone level, and mean platelet volume

OBJECTIVE

This study is a survey of the determinants of refractoriness to the pressor effects of angiotensin II during normal pregnancy.

STUDY DESIGN

In 25 normal pregnant women, the effective angiotensin II pressor dose was determined 88 times from the twenty-fifth to the thirty-second week of gestation. Immediately before the angiotensin II infusion, blood samples were collected and measured for plasma angiotensin II concentration, serum progesterone level, platelet count, and mean platelet volume.

RESULTS

The effective pressor dose had a significantly positive correlation with plasma angiotensin II concentration and serum progesterone level and a negative correlation with mean platelet volume.

CONCLUSION

The pregnancy-associated refractoriness to angiotensin II is physiologically determined, at least in part, by the elevated circulating levels of endogenously produced angiotensin II and by the progesterone produced by the placenta, whereas platelet activation attenuates the relative refractoriness during normal pregnancy.

Erythropoietic adaptations to endurance training

Erythropoietic adaptations involving the oxygen dissociation curve (ODC) and erythropoietin production have been implicated in the etiology of reduced blood haemoglobin concentrations in sportspersons (known as sports anaemia). A significant increase in the half-saturation pressure indicating a right-shift in the ODC was measured in 34 male [25.8-27.4 mmHg (3.44-3.65 kPa)] and 16 female (25.8-27.7 mmHg (3.44-3.69 kPa)] trained distance runners (P less than 0.01 for both genders) after completing a standard 42-km marathon. Erythrocyte 2,3-diphosphoglycerate concentrations measured concurrently were unaltered by exercise, although consistently higher in the female compared to the male athletes (P less than 0.05). The serum erythropoietin (EPO) concentrations of 15 male triathletes (26.3 U.ml-1) were significantly lower than those of 45 male distance runners (31.6 U.ml-1; P less than 0.05). However, the mean serum EPO concentrations of male and female athletes engaged in a variety of sports were not different from those of sedentary control subjects of both sexes (26.5-35.3 U.ml-1). Furthermore, the serum EPO concentrations were unaltered after prolonged strenuous exercise in 20 male marathon runners. These data suggest that the haematological status of these endurance athletes is in fact normal and that the observed shift in the ODC, while providing a physiological advantage during exercise, has no measurable effect on the erythropoietic drive.

Athletes' pseudoanaemia

To characterize the so-called pseudoanaemia of endurance-trained athletes, the plasma volume (PV), red cell volume (RCV) and total blood volume (TBV) of 12 male and 12 female athletes and 5 male and 5 female nonexercising controls were measured using 125I-labelled human serum albumin and 51Cr-labelled erythrocytes. The mean PV of the male athletes (52.8 ml.kg-1) was 37.5% higher than that of the controls (38.4 ml.kg-1), while the 18.1% increase measured in the female runners (51.5 ml.kg-1) over the controls (43.6 ml.kg-1) was a novel observation. Although the RCV was significantly greater (34.7%) in male athletes (32.6 ml.kg-1 vs 24.2 ml.kg-1 in the controls), a similar elevation (3.6%) was not found in the female athletes (25.9 ml.kg-1) compared to the sedentary women (22.8 ml.kg-1). This could have been due to iron-limited erythropoiesis because the RCV of the female athletes defined as clinically anaemic was markedly lower that of the nonanaemic women (P less than 0.05). The elevated plasma protein mass and concentration measured in the athletes partly accounted for their expanded PV. It was concluded that the decreased blood haemoglobin levels reported in the endurance athletes was largely a dilutional effect.

[Colloid substitutes and hematocrit measurement by micromethods]

A study was carried out to determine whether centrifugation and resistivity were reliable methods for measuring haematocrit of blood diluted with dextran or gelatin. The values obtained with the minicentrifuge Compur M 1100 (Bayer) (group 2) and with the Stat-Crit (Fumouze) (group 3) were compared with those obtained with the reference method (Coulter counter Model S + 2, Coultronics) (group 1). The study included 10 healthy subjects, aged 21 to 43 years. In each, sodium, potassium, chloride and protein concentrations were determined. Two further 10 ml blood samples were taken to be diluted with increasing amounts of either a fluid modified gelatin (Plasmion) or a dextran 40 (Piasmacair). The dilutions carried out were 0, 10, 20, 30, 40 and 50%. For each one, the haematocrit was measured using all three methods. The values obtained with undiluted blood were similar with the three methods. However, when blood was diluted with a dextran, haematocrit values were underestimated, whatever method was used, but by no more than 5% (difference not statistically significant). The result was the same with the centrifugation method for blood diluted with gelatin. On the other hand, values obtained with the resistivity technique for these samples were underestimated up to 15.5% (50% dilution; p less than 0.05). This was due to the negative electric charge of the gelatin, which lowered the haematocrit value in proportion to the concentration of gelatin. Although the technique is easier than centrifugation, measuring haematocrit with a resistivity method should be avoided in patients receiving a fluid modified gelatin.

Incorporating severity of illness into estimates of likelihood ratios

Although severity of illness may affect the usefulness of a diagnostic test, most previous work has considered test performance only in the dichotomous situation where the target disorder is considered present or absent. In this paper, a clinical example is provided and two methods presented whereby illness severity may be incorporated into the determination of likelihood ratios for a diagnostic test. The use of this approach is that given a test result, a clinician may determine the post-test probability of all levels of the illness in the patient under study.

Derivation and validation of a prediction rule for identifying heavy consumers of alcohol

Using two population-based cohorts of men aged 45-59, we sought to derive and validate a prediction rule for identifying heavy consumers of alcohol. Eighty-five percent of eligible men on electoral rolls in Caerphilly, Wales (derivation set, N = 2512) and 90% of eligible men on the practice lists of 16 Speedwell, England, general practitioners participated (validation set, N = 2348). Alcohol consumption was assessed by questionnaire with heavy alcohol consumption defined as the top 10% of the Caerphilly population's alcohol usage (greater than 525 cc ethanol per week). The prediction rule, Score = (mean corpuscular volume x 1.00) + (body mass index x 0.31) + (systolic blood pressure x 0.08) + HDL-cholesterol x 9.24) + (fasting triglyceride x 2.20) was derived by multiple linear regression in the Caerphilly cohort and validated in the Speedwell cohort. Comparing the lower 20% of the Score distribution with the upper 5%, likelihood ratios increased from 0.15 to 5.29 and 0.06 to 7.42 in the Caerphilly and Speedwell cohorts, respectively. Having a score of 136.30 or greater yielded a relative risk of being a heavy drinker of 23.1 (95% Cl = 10.1-53.0) in Caerphilly and 99.3 (95% Cl = 12.8-769.5) in Speedwell. The derived prediction rule is a valid diagnostic aid to help clinicians identify heavy alcohol consumers.

The comparison of gammaglobulin to steroids in treating adult immune thrombocytopenia. An interim analysis

Symptomatic immune thrombocytopenia is a life-threatening situation which is conventionally treated in the adult with prednisone, although subsequent splenectomy is frequently unavoidable. Recently, high-dose intravenous gamma-globulin has been reported to be an effective alternative option, particularly in children. To determine the role of this agent in adults a controlled prospective trial has been undertaken. Previously untreated patients with immune thrombocytopenia were randomised to compare oral prednisone (1 mg/kg/day: Group 1: n = 13) to high-dose intravenous gamma-globulin (400 mg/kg on days 1 through 5: Group 2: n = 7), or a combination of both agents given on the same schedule (Group 3: n = 12). The time from diagnosis to commencement of treatment, initial platelet counts, age and sex were comparable in the three groups. At this interim analysis there has been no mortality, but one patient has suffered a cerebrovascular accident. Objective response, defined as a platelet count greater than 50 x 10(9)/l, was achieved in a median of 5, 5 and 3 days, whereas the time taken to reach peak counts were 9, 5 and 7 days, respectively. The relapse rates, percentage of patients subsequently requiring splenectomy for control of symptomatic bleeding and the postoperative course was comparable between the three groups. These data, although preliminary, re-emphasize differences between the paediatric and adult forms of immune thrombocytopenia and also suggest in the latter patients a need for caution before advocating replacement of prednisone by gammaglobulin as the primary form of treatment.

Response in serum ferritin and haemoglobin to iron therapy in blood donors

Seven hundred seventeen healthy male blood donors regularly donating four or more units a year were surveyed for haemoglobin and serum ferritin levels. One hundred fifty-one (21%) had a haemoglobin less than 13.5 g/dl and were therefore disqualified from further blood donation, having a mean serum ferritin of 28 micrograms/liter. Of the remaining 566 donors with haemoglobin levels equal to or greater than 13.5 g/dl, the mean serum ferritin was 33 micrograms/liter, although in 299 (53%) the value was less than 28 micrograms/liter. To document response to iron therapy 46 donors with haemoglobin levels equal to or greater than 13.5 g/dl were stratified into those with the lowest iron stores (group 1; n = 23), defined as a serum ferritin less than 20 micrograms/liter, and controls (group 2; n = 23), with serum ferritin between 50 and 150 micrograms/liter. Within each stratum donors randomly received ferric polymaltose at a dose of 100 mg elemental iron twice daily for 56 days (groups 1a and 2a) or an identical iron-free placebo tablet administered on the same schedule (groups 1b and 2b). Iron therapy in the iron-deficient group (group 1a:n = 11) resulted in a significant rise in haemoglobin (p = .03) and iron stores reflected in serum ferritin (p = .002) compared to those receiving placebo (group 1b). In the control group iron therapy or placebo was without significant effect. Thus, ferric polymaltose preparation is bioavailable and is notable for the virtual absence of gastrointestinal tract side effects.

Predictive value of mean platelet volume in gold induced thrombocytopenia

In rheumatoid arthritis the mean platelet volume does not alter with the institution of parenteral gold therapy and with long term gold therapy. It appears to have no value in predicting the onset of thrombocytopenia. It may, however, predict a haemorrhagic diathesis once gold induced thrombocytopenia is established.

Lack of short-term effects on the donor during continuous-flow selective mononuclear cell collection

In 50 individuals, intensive harvesting of relatively pure mononuclear cell fractions from the peripheral circulation was carried out in 195 procedures. Serial collections from bone marrow donors (group 1: n = 35) or isolated procedures from volunteers (group 2: n = 15) were without morbidity. A median yield of 4.0 X 10(9) mononuclear cells were recovered in a final volume of 104 ml of cell-rich plasma, for which 4,300 ml of venous blood was processed in 107 minutes. In neither group were changes documented in donor white cell count or lymphocyte numbers. In group 1, a statistically significant but clinically unimportant and transient fall occurred in the platelet count at the end of the 5-day intensive schedule. It is concluded that mononuclear fractions can efficiently be collected from normal donors without the development of relevant cell depletion.

Busulphan versus combination chemotherapy for initial treatment of chronic granulocytic leukaemia

In a pilot study, 21 consecutive and previously untreated adults with chronic granulocytic leukaemia received either busulphan (group 1: n = 11) or a combination of the epipodophyllotoxin VP16-213 with cytosine arabinoside and doxorubicin (group 2: n = 10). Using a standardised protocol, objective response, defined as a granulocyte count consistently less than 10 X 10(9)/1 with no clinical evidence of the disease, was achieved in 45 and 40% of the patients, respectively, and median survivals were 89 and 107 weeks (p greater than 0.05). Although there was no difference in morbidity, the study was discontinued because the combination chemotherapy was more complex to administer, was associated with greater patient inconvenience, and offered no advantage over single-agent therapy in managing the stable phase of chronic granulocytic leukaemia.

Platelet volume analysis in thrombocytopenia in relation to bleeding tendency

It has been shown that large platelets are hemostatically more active than the smaller ones. We therefore studied the relationship between the mean platelet volume and the percentage of micro- and mega-thrombocytes measured by a Coulter counter S plus II, and the bleeding tendency in 57 unselected patients with a platelet count below 50 X 10(9)/l. We found no significant differences for any of these parameters between patients without and those with mild or severe bleeding tendency. This also held true when patients with a possible platelet dysfunction or with coagulation abnormalities were excluded. We conclude that platelet volume analysis in unselected patients with severe thrombocytopenia is not helpful in the prediction of their risk of bleeding.

Platelet 5-HT uptake in delusional and nondelusional depressions

Platelet 5-hydroxytryptamine (5-HT) uptake was measured in a group of 28 endogenously depressed patients, at three points during the day, before, during and after treatment. It was also measured in 20 controls at the same three times. Uptake rates varied in control subjects in a manner consistent with the presence of a circadian rhythm in uptake. This variation was absent in depressed subjects. Deluded and nondeluded depressives showed a similar absence of variation but differed in the absolute values for their uptake rates. In particular deluded depressives did not show the lowering of platelet uptake rates, which has been widely reported for endogenous depression. This difference between the two groups was maintained after treatment was started but was not present after clinical recovery, suggesting a state-rather than trait-dependent marker. These differences between deluded and nondeluded depressives have implications for the investigation of platelet 5-HT uptake in other psychiatric illnesses.

Marathon Running Fails to Influence RBC Survival Rates in Iron-Replete Women

In brief: As many as 80% of female long-distance runners show iron deficiency. One explanation is RBC fragmentation due to mechanical trauma. In this study, radiolabeling was used to measure RBC survival rates in six iron-replete female marathon runners. In addition, tests for urinary hemosiderin were conducted in a search for secondary evidence of RBC damage. Radioactivity counts on blood samples drawn before and after a standard 26-mile marathon failed to disclose traumatic RBC fragmentation, and the tests for urinary hemosiderin were negative. Other possible factors in iron deficiency, such as diet, therefore merit consideration.

Longitudinal study of platelet indices during normal pregnancy

The purpose of this longitudinal, prospective study was to define platelet indices during normal pregnancy and to compare them to normal nonpregnant values. Indices evaluated included platelet count, mean platelet volume, and platelet distribution width. No significant change occurred in the mean platelet count or mean platelet volume from the second to the third trimester; however, platelet distribution width increased progressively and significantly during this interval (p less than 0.0001). Mean platelet volume versus platelet count showed a significant inverse relationship (p less than 0.0001) and was congruent with normal nonpregnant values. Mean platelet volume versus platelet distribution width exhibited a significant direct relationship (p less than 0.03) that differed remarkably from normal nonpregnant values. These data support the concept of normal pregnancy as a compensated state of progressive platelet consumption. These findings may have important diagnostic and prognostic applications in discerning acute states of platelet consumption superimposed on the compensated consumption of normal pregnancy.

Platelet volume analysis for differential diagnosis of thrombocytosis

The results of the Coulter counter S plus II platelet volume analysis were studied in 100 patients with reactive thrombocytosis (platelet count greater than 500 X 10(9)/l), in 30 patients with myeloproliferative thrombocytosis, and in 32 patients with chronic myeloproliferative disease and a platelet count less than 500 X 10(9)/l. Patients with reactive thrombocytosis had considerably lower mean platelet volumes than those with myeloproliferative thrombocytosis, or normal subjects. The opposite was true for the platelet distribution width. This index for platelet heterogeneity was normal in reactive, but increased in myeloproliferative thrombocytosis. There were no differences in mean platelet volume or platelet distribution width between patients with myeloproliferative disease and a high or normal platelet count. The increased platelet heterogeneity in myeloproliferative disease was caused by an increase of both small and large platelets. The platelet distribution width seemed to be the best variable for the differential diagnosis of thrombocytosis. A platelet distribution width greater than 17 was found in 26 of the 30 patients with myeloproliferative thrombocytosis but in only five of the 100 patients with reactive thrombocytosis. A normal platelet distribution width in a patient with a high platelet count strongly suggests reactive thrombocytosis.

The effect of serial therapeutic plasmapheresis on platelet count, coagulation factors, plasma immunoglobulin, and complement levels

One hundred therapeutic plasmaphereses were carried out at biweekly intervals in seven patients, without morbidity or mortality, using the IBM 2997 blood fraction separator. In standardised procedures, 1.5 times the calculated plasma volume was replaced with an electrolyte solution containing 4% salt-free human albumin. Anticoagulation was achieved using a whole venous blood to acid-citrate dextrose ratio of 11 to 1. Median flow rates, plasma collection, and procedure times were respectively 40 ml/minute, 20 ml/minute, and 3 hours. Haemoglobin and total white cell counts were not significantly affected by the procedures. In contrast, platelet count, fibrinogen, immunoglobulin levels, total haemolytic complement, as well as C3 and C4 fractions fell, and the prothrombin and partial thromboplastin times were lengthened by the exchanges. All these measurements had returned to normal within 24 hours, apart from the fibrinogen, which took between 48 and 72 hours, and the immunoglobulin level, which required 35 days to return to baseline. In a further patient, more detailed studies (n = 13) were carried out to characterise the behaviour of antithrombin III and factor VIII. Both levels were markedly reduced immediately following the procedure and, like fibrinogen, had returned to normal within 48 hours. These data indicate that in an isovolemic plasmapheresis there was a transient but rapidly reversible effect on all the factors studied, with fibrinogen level, antithrombin III, and factor VIII returning more slowly to normal than the others, and immunoglobulin levels responding the slowest. None of these changes was associated with clinically significant haemostatic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Variations in platelet 5-hydroxytryptamine in control and depressed populations

Platelet 5-hydroxytryptamine uptake was measured in a group of 28 endogenously depressed patients at three points during the day, before, during and after treatment and in 20 controls at the same three times. Uptake rates varied in control subjects in a manner consistent with the presence of a circadian rhythm in uptake. This variation was absent in depressed subjects. Normal variation was restored in those patients showing a clinical response, irrespective of the effects of treatment on the affinity of the uptake system. This restoration was not found in nonresponders or acutely after treatment was commenced. These findings suggest that depression is associated with a disruption of circadian rhythms, that abnormalities of platelet 5-hydroxytryptamine uptake are secondary to such a disruption and that antidepressants may act to correct this disruption.

The routine measurement of platelet volume: a comparison of light-scattering and aperture-impedance technologies

The effect of dipotassium ethylenediaminetetra-acetic acid (EDTA) on platelet count and mean volume (MPV) was evaluated using two routine measurement systems, a Coulter S Plus (Phase 1) (S+) and a Technicon H6000 (H6000). In normal subjects (n = 29) MPV increased by 17% during 39 h storage in EDTA when measured by the S+. In contrast MPV decreased by 22% when measured by the H6000. MPV differences of up to 40% were observed between the two systems. Concomitant platelet counts, in both systems, changed by less than 4%. A mathematical model of the variation of MPV with storage time was constructed, enabling experimental results to be extrapolated, with accuracy, to time zero (MPV0). The H6000 average MPV0 was significantly larger than the S+ average MPV0. Using the anticoagulant sodium citrate and prostaglandin E1 (NaCitrate-PGE1) there were no significant changes in MPV measured by the S+ during 7 h storage, although a linear decrease in platelet count was observed. A decrease in H6000 MPV was observed whether the blood was stored in EDTA or NaCitrate-PGE1. Methodology, anti-coagulation and storage time all influence MPV. Until these determinants are standardised the clinical value of MPV cannot be assessed.

Platelet collection using the IBM 2997 cell separator

Platelets were collected using the dual-channel module on the IBM 2997 Blood Fraction Separator. We carried out 320 procedures to harvest platelets for therapeutic purposes and yielded 5.1 +/- 1.5 X 10(11) platelets (mean +/- SD). Infusion into previously unsensitized recipients with hypomegakaryocytic thrombocytopenia achieved increments at 1 hr of 19 +/- 7.3 X 10(9)/liter/m2 (mean +/- SD) and at 24 hr of 15 +/- 6.3 X 10(9)/liter/m2. The only consistent donor reaction was mild hypocalcaemia, easily corrected by calcium gluconate infusion. Changes in donor packed-cell volume and white cell count were not statistically altered (p greater than 0.05) but donor platelet counts fell from 216 +/- 43.1 X 10(9)/liter to 162.5 +2- 41.7 X 10(9)/liter (mean +/- SD) (p less than 0.01). Additional plateletphereses were carried out in seven normal volunteers, using the same technique, in order that the function of the harvested platelets could be studied. Following radiochromium labelling and reinfusion into the same donors, normal in vivo recoveries were obtained at 10 min (59.4 +/- 3.4%; mean +/- SD) and platelet mean life span was also normal (218 +/- 12 hr; mean +/- SD). Furthermore, in vitro platelet factor III availability and aggregation patterns of the harvested platelets did not differ from control values and their ultrastructural appearance was normal.

Immunophenotypic classification of lymphoblastic leukaemia and lymphocytic lymphoma--an experience in the south-western area of the Cape Province of South Africa

Adequate tumour material was obtained for phenotypic classification using a standard library of monoclonal antibodies from 81 previously untreated patients with acute lymphoblastic leukaemia (ALL), chronic lymphocytic leukaemia (CLL), or lymphocytic lymphoma (LL). Sixty-one individuals were adults and 20 were children of 14 yr or younger. Fifty-eight of the patients (72%) had acute lymphoblastic leukaemia and the remaining 23 (28%) had chronic lymphocytic leukaemia or lymphocytic lymphoma. Considering only the patients with acute lymphoblastic leukaemia (n = 58) the median age was 19 yr (range 3-69 yr): 9% were black, 43% were coloured, 48% were white, and the distribution between adult (n = 38) and paediatric patients (n = 20) was comparable. Complete remission rate in the adults was 58% and in the paediatric group 85%. For the total group (n = 58) median duration of survival was 59 weeks for common, 39 weeks for null, 63 weeks for T-ALL, and 13 weeks for B-ALL subtypes. In both the common and the null groups overall and disease-free survival was superior in the children. In contrast, no difference was evident in the T-ALL group, which was also notable for its high incidence in young coloured males. The 15 patients with CLL and eight with LL were adults and all the cells were phenotypically of B lineage: in view of the small numbers no comments are possible about ethnic differences. A multi-centre collaborative study is needed to define the epidemiology of haematologic malignancy in South Africa, with emphasis on differences among ethnically distinct subpopulations.

Hyperthyroidism and immune thrombocytopenia

Hyperthyroidism and immune thrombocytopenia occurred concurrently in five patients; in a sixth, thyrotoxicosis developed after successful treatment of the thrombocytopenia. Correction of the hyperthyroidism was followed by a variable pattern of clinical response. In one case with mild asymptomatic thrombocytopenia spontaneous complete remission occurred. Two patients required adrenocorticosteroids to control severe thrombocytopenic purpura during the period of hyperthyroidism, after which complete remission occurred. Another patient with severe symptomatic thrombocytopenia remains with a partially compensated thrombocytolytic state but is without purpura and off all therapy. A fifth patient required splenectomy for drug-resistant thrombocytopenia and remains critically dependent on immunosuppressive therapy. The sixth patient had a relapse of immune thrombocytopenia with subsequent development of thyrotoxicosis but platelet count spontaneously returned to normal after correction of the hyperthyroidism. Pregnancy in two of these six patients was not associated with recurrence of either hyperthyroidism or thrombocytopenia. Management of symptomatic purpura in adults with co-existent hyperthyroidism may differ from that customarily employed since adrenocorticosteroid therapy may need to be extended until euthyroidism has been established before proceeding to splenectomy. When surgery is necessary, the risk of thyrotoxic storm should be anticipated, and the patient appropriately premedicated.

Centrifugal and anticoagulant induced variations in platelet rich plasma and their influence on platelet aggregation

Variations in the centrifugal force (g) used to prepare platelet-rich-plasma (PRP) alter not only the number of platelets therein but also their size and reactivity. Anticoagulants also affect these parameters. According we suggest that PRP preparations need to be strictly standardised. Critical comment on the use of the platelet aggregation model as a means of assessing 5-hydroxytryptamine receptor function is included.

Dyskeratosis congenita. Haematologic, cytogenetic, and dermatologic studies

In a family of 5 boys and 6 girls, 3 brothers have clinical dyskeratosis congenita. Teeth from 2 of the patients were taurodent , and mineral density of the enamel was significantly different from normal. The haematopoietic marrow was hypocellular and there was striking prominence of plasma cells having normal morphology; no granulomata were demonstrated. The decreased erythroid precursors in the marrow correlated with quantitatively reduced erythropoiesis demonstrated on ferrokinetic studies. Recurrent infections occurred but could not be related to neutropenia, and granulocytes and monocytes retained normal function. No abnormality was demonstrated in humoral or cellular immune mechanisms. While superficially similar, dyskeratosis congenita and Fanconi's anaemia are genetically distinct, being X-linked in the former and inherited as an autosomal recessive in the latter.

In adult acute nonlymphoblastic leukaemia extended maintenance chemotherapy has no benefit

Fifty-two consecutive and previously untreated adults with nonlymphoblastic leukaemia underwent remission induction chemotherapy with a combination of the epipodophyllotoxin VP16-213, cytosine arabinoside, and doxorubicin (Adriamycin). Complete remission was achieved in 23 of the 52 patients (44%) by means of a single course of therapy in 20 individuals, two courses in two, and three courses in one; median duration of complete remission was 48 weeks. Failure to achieve remission status was due to primary drug resistance in 13 patients (25%), and adequate trial of therapy was not possible in 16 patients (31%) owing to their late referral and accounts for the low remission rate. Individuals achieving complete remission were randomly assigned to receive either 6 (n = 8) or 15 months (n = 13) of maintenance therapy; respective median survival was 95 and 78 weeks (P greater than 0.10). These data confirm previously reported results for complete remission induction with this three-drug combination and fail to show any difference between short (6 months) and long (15 months) maintenance chemotherapy.

Comparison of filtration to continuous-flow centrifugation for plasma exchange

The Asahi Plasmaflo Hollow Nylon Fibre Filtration System (n = 13) was directly compared to the NCI-IBM 2990 Continuous-Flow Blood Fraction Separator (n = 10) for plasma exchange. The systems were equally efficient in achieving plasma separation. There were significant differences favouring filtration for clearance of fibrinogen (P less than 0.05), and the fourth component of complement (P less than 0.01). Greater loss of urea (P less than 0.05) was found after plasma exchange, using the cell separator. The flow characteristics were markedly different. In a standardised 4-L plasma exchange, filtration took place at 35 ml/minute, with a procedure time of 109 +/- 45 minutes in contrast to centrifugation at a plasma flow collection rate of 19 ml/minute, requiring 208 +/- 17 minutes. This time advantage for the former procedure was offset by 195 minutes required to regenerate the hollow nylon fibre unit and a further 90 minutes required for cleaning under strictly controlled aseptic techniques prior to reuse. Each filter was regenerated at least twice and reused without infection, but there was incremental loss of filtration efficiency demonstrated by decreasing clearance of an intravascular marker dye. In two of the 13 procedures using the Plasmaflo system, serious reactions necessitated termination of the procedure; this did not occur using the cell separator. Restriction of the number of times that the filter unit could be regenerated without loss of efficiency, the prolonged time required for regeneration and cleaning, coupled with the need for artificial vascular access to meet high blood flow rates required, limit the usefulness of this technique for plasma exchange.

The function and structure of granulocytes collected using the IBM 2997 separator

The effect of oral methylprednisolone and the sedimenting agent, hydroxyethyl starch, on granulocyte recovery, morphology, and function was studied in a volunteer donor programme. Using the IBM 2997, 10 litres of whole blood were processed, with an average procedure time of 2.4 hours and a collection volume of 300 ml. Donors not receiving methylprednisolone (n = 80) had a mean total granulocyte count of 3.5 X 10(9)/litre (range 1.6-5.3 X 10(9)/litre) and mean granulocyte yields were 1 X 10(10) (range 0.2-3.0 X 10(10)). Those receiving 48 mg oral methylprednisolone 6-8 hours before the procedure (n = 320) had a mean granulocyte count of 6.3 X 10(9)/litre (range 3.2-11.4 X 10(9)/litre) and significantly superior mean granulocyte yields of 2.0 X 10(10) (0.3-6.5 X 10(10)) (P less than 0.05). For both groups the mean packed cell volume of 0.08 litre/litre (range 0.02-0.17) and platelet contamination 1.9 X 10(11) (range 0.3-5.0 X 10(11)). In all these procedures, hydroxyethyl starch was added to the blood entering the centrifuge channel. In none of the procedures were any untoward symptoms experienced by the donors. Light microscopy and ultrastructural studies showed no difference between control granulocytes and those collected following the addition of hydroxyethyl starch or after oral methylprednisolone. Similarly, granulocyte function measured with a random migration, chemotaxis, phagocytosis, and intracellular killing was not significantly different between control cells and those exposed to the sedimenting agent or the adrenocorticosteroids (P greater than 0.10). It is concluded that donor premedication with methylprednisolone significantly enhances granulocyte yields in the presence of hydroxyethyl starch and neither agent has any demonstrable effect on granulocyte morphology or function.

Platelet size in myocardial infarction

The mean platelet volume and platelet count were measured serially in 100 patients soon after myocardial infarction and again at a follow up clinic about seven weeks later. The results were compared with those in age matched controls. The mean platelet volume after infarction (mean 9.07 fl (SE 0.08] was significantly greater than in the controls (8.32 fl (SE 0.07); p less than 0.001), and was still raised at the follow up clinic (8.69 fl (SE 0.10); p less than 0.01). The mean platelet count on admission (275 X 10(9)/1 (SE 7] was significantly lower than in the control group (295 X 10(9)/1 (SE 5); p less than 0.05) and fell significantly during admission, with a mean change of -36 X 10(9)/1 (95% confidence limits -26, -45; p less than 0.01). At the follow up clinic the platelet count had risen to a level not significantly different from the admission value. As larger platelets are haemostatically more active, the finding of an increased mean platelet volume after myocardial infarction provides further evidence that abnormal platelet behaviour may be implicated in the process of infarction.

Increased mean platelet volume in septicaemia

An increased mean platelet volume (MPV), measured by the Coulter counter model S plus, was found in 13 of 25 patients with proven septicaemia but in none of 25 patients with localised bacterial infection and negative blood cultures. The increase in MPV was found both in patients with normal and low platelet counts and was not related to a particular micro-organism. Patients who responded favourably to antibiotic treatment all had normal MPVs after one week of treatment. However, 9 of 11 patients with a prolonged course of their infection due to endocarditis or abdominal abscesses had raised MPVs after seven days of treatment, and four patients who died of infection in the first week all had increased MPVs on the day of their death. An increased MPV in a patient with bacterial infection possibly indicates that the infection has become invasive--that is, that septicaemia has occurred. A persistent rise or further increase indicates that treatment is inadequate.

Platelet size: no correlation with migraine or monoamine oxidase activity

A Coulter Model "S Plus" counter has been used to study platelets from 39 migrainous patients between attacks, six during attacks, eight with active cluster headache and 26 controls. None of the patient groups showed any abnormality in platelet size profile. There was no correlation between platelet monoamine oxidase activity and mean platelet volume in any of the groups.

Prediction of haemorrhagic diathesis in thrombocytopenia by mean platelet volume

The Coulter counter, model S Plus, Provides a platelet count and a mean platelet volume in all routine specimens of blood for cell count. The value of mean platelet volume in the prediction of the haemostatic potential of thrombocytopenic patients was investigated in 175 patients with haematological disorders who underwent 1473 blood counts over five months. Eighty-four haemorrhagic episodes were detected, most in thrombocytopenic patients. The mean platelet volume of patients with haemorrhagic tendency was significantly lower (5.52 +/- SD 0.7 fl) than that of patients without these tendencies (7.87 +/- SD 1.75 fl) (p less than 0.001). In cases of severe thrombocytopenia (less than 20 x 10(9)/1 platelets) haemorrhagic episodes were frequent; however, the frequency of bleeding was considerably lower in cases in which the mean platelet volume was higher than a suggested cut-off point of 6.4 fl. Discriminant analysis selected mean platelet volume as more important than platelet count for prediction of haemorrhagic state in severe thrombocytopenia. In view of the useful discrimination that mean platelet volume provides between thrombocytopenic patients who bleed and those who do not bleed, it may serve as a guide to predict the danger of haemorrhage and the need for prophylactic platelet transfusion.

Size dependent platelet subpopulations: relationship of platelet volume to ultrastructure, enzymatic activity, and function

A method for the separation of platelets on the basis of their size has been developed using counterflow centrifugation. Platelets were separated, free of plasma proteins and other cells, into seven subpopulations. The smallest-sized platelets, designated as Fraction 1, had a mean platelet volume (MPV) of 3.94 +/- 0.60 micrometer 3 (SD). Each successive fraction had a progressively larger MPV. The MPV for the largest-sized platelets, designated Fraction 7, was 8.19 +/- 0.64 micrometer 3. The MPV for the original platelets prior to fractionation was 6.57 +/- 0.61 micrometer 3. The mean density of Fraction 1 platelets was 1.067 +/- 0.002 g/cm3, while Fraction 7 had a mean density of 1.072 +/- 0.001 g/cm3. Transmission electron microscopy demonstrated that Fraction 1 had 4.3 +/- 0.9 dense bodies per platelet, and Fraction 7 had 12.6 +/- 2.4 dense bodies per platelet. Platelet LDH activity showed that the Fraction 1 platelets had 4.77 +/- 0.92 iu per 10(10) platelets; Fraction 7 platelets had 14.88 +/- 1.23 iu per 10(10) platelets. The LDH activity in the platelets before separation into subpopulations was 9.47 +/- 1.45 iu per 10(10) platelets. Platelet function was measured by ADP-induced aggregation, serotonin uptake, and thrombin-induced release. Progressively more rapid and more complete aggregation was observed as the platelet size increased over the seven fractions. Serotonin uptake was 4.2 times greater in the Fraction 7 platelets than in the Fraction 1 platelets. Quantitative release of serotonin following thrombin stimulation was significantly greater in the larger-sized platelets than in the smaller-sized platelets. The observed differences in platelet aggregation, dense body content, LDH activity, and serotonin uptake and release suggest that large platelets may be functionally more important than smaller platelets.

Comparison of Channelyser and Model S Plus determined platelet size measurements

A comparison has been made between Coulter Counter ZBI/Channelyser C1000 derived platelet distribution width (PDW), mean platelet volume (MPV) and platelet crit (PCT) with similar measurements generated by the Coulter counter Model S Plus. Correlations of PDW and MPV from the two systems are poor; that for PCT is acceptable. The differing results can almost certainly be attributed to physical differences in the measurement systems.