Oxygen desaturation in apparent and relative polycythaemia.
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Adult↗
Biomedical subjects
M Messinezy
Publications and source records attributed to M Messinezy.
A retrospective study of apparent and relative polycythaemia: associated factors and early outcome.
Thirty four consecutive patients (31 male, 3 female) with raised PCV (males greater than 0.51, females greater than 0.47) and normal red cell mass (apparent polycythaemia) and with normal red cell mass but a low plasma volume (relative polycythaemia) were studied retrospectively. Male sex, smoking, hypertension and diuretic therapy were found to be associated factors while obesity and excessive alcohol consumption were less clearly linked. Only three patients (all males) were negative for all these factors. Approximately 15% of patients had arterial hypoxaemia. There was no difference in the incidence of these factors in the two sub-groups. Possible mechanisms relating these factors to the raised PCV are discussed. Preliminary follow-up data show that in approximately one third of the patients the PCV returns to normal and that this is most likely in those patients with a normal recumbent PCV (at the time of the blood volume study). In one third the PCV continues to be raised, and the remainder have only intermittently raised PCV. As a result of this study, prospective studies of the incidence of hypoxaemia in these patients and of the PCV outcome with and without correction of associated factors are planned.
Adult↗
Primary thrombocythaemia: diagnostic criteria and a simple scoring system for positive diagnosis.
Forty new patients with elevated platelet counts (greater than 600 x 10(9)/l) and without palpable splenomegaly were assigned to diagnostic groups defined by essentially conventional criteria after 3 months follow up: Proliferative (17), reactive (17) or unclassified (six). Mean platelet volume (MPV), platelet distribution width (PDW), platelet nucleotide ratio (ATP:ADP), unstimulated BFU-E derived colony formation from peripheral blood, spleen scan and clinical ischaemia were assessed at the outset, with a view to defining diagnostic criteria for distinguishing primary thrombocythaemia from reactive thrombocytosis. All except the first variable were significantly associated with diagnostic group (P less than 0.05). A simple scoring system was devised: enlarged spleen on scan, or presence of BFU-E, each scored 2; elevated PDW (greater than 2 SD from mean), elevated ATP:ADP (greater than 4 SD from mean) or presence of clinical ischaemia, each scored 1. Score totals greater than or equal to 3 predicted primary thrombocythaemia, and totals less than 3 suggested reactive thrombocytosis (predictive value 89%). The system correctly predicted diagnosis in four out of four (probably six out of six) patients whose diagnosis was not apparent initially, and thus whose results were not used in constructing the scoring system. Exclusion of BFU-E from the system resulted in only one incorrect prediction in this group.
Blood Platelets↗
Use of splenic volume estimation to distinguish primary thrombocythaemia from reactive thrombocytosis.
Splenic volume was measured by visual assessment of planar images of the spleen, and also by single photon emission computerised tomography (SPECT) using 99mtechnetium tin colloid, in a group of 33 patients with primary thrombocythaemia (PT) or reactive thrombocytosis. Volumes greater than 337 cm3 correlated strongly though not absolutely with PT, all patients with volumes greater than this figure being in the PT group. Simple visual assessment of planar images by an experienced observer matched measured splenic volumes very closely.
Adult↗
Polycythaemia and thrombocythaemia in the elderly.
The investigation of elderly patients presenting with raised PCV values has been described. Suitable clinical and laboratory investigation enables the separation of those with a raised red cell mass (RCM) into three groups: primary proliferative polycythaemia (PPP), secondary polycythaemia and idiopathic erythrocytosis. Those patients with a raised PCV but normal RCM either have apparent polycythaemia (normal plasma volume) or relative polycythaemia (low plasma volume). PPP is a clonal disorder with a peak incidence in the elderly. It commonly presents with vascular occlusive symptoms/signs involving larger vessels, both arterial and venous. The microvasculature may also be involved, particularly when there is associated thrombocythaemia. Effective treatment is required to minimize the future vascular occlusive incidence and diminish the complication rate of surgery if it is ever required. Both the PCV and the platelet count, if elevated, should be adequately controlled. 32P is probably the simplest treatment and is very effective, but venesection and intermittent low-dose busulphan is equally satisfactory in the co-operative patient with good peripheral veins. Secondary polycythaemia may arise from a variety of causes, particularly from arterial hypoxaemia and renal lesions. Occasionally, more than one pathology is identified in the elderly patient. Lung disease is the most common cause of hypoxaemia. Venesection may be indicated in those patients with excessively raised PCV values. The term idiopathic erythrocytosis should only be used for patients who have been adequately investigated. These patients most commonly present with ischaemic or vascular occlusive symptoms/signs. Relative polycythaemia may be caused by fluid loss, but generally the origin of the low plasma volume is not established. Apparent polycythaemia may represent a physiological variant or a stage before the development of a definitely raised RCM. The management of idiopathic erythrocytosis, and relative and apparent polycythaemia, should initially involved removal of known risk factors if present (e.g. hypertension) with the addition of venesection in selected patients. Reactive thrombocytosis in the elderly is most commonly due to malignant disease of chronic infection. The high platelet count is usually asymptomatic, and antiplatelet therapy is rarely required. Primary thrombocythaemia (PT) is a clonal myeloproliferative disorder similar to PPP. The finding of splenomegaly, abnormal platelet morphology or function helps to separate PT from reactive thrombosis. PT most commonly presents with digital or transient cerebral ischaemia or haemorrhage.(ABSTRACT TRUNCATED AT 400 WORDS)
Aged↗
Determination of serum immunoreactive erythropoietin in the investigation of erythrocytosis.
We assessed the diagnostic value of determinations of serum levels of immunoreactive erythropoietin in 90 patients referred for the investigation of a raised packed red-cell volume (hematocrit) and possible erythrocytosis (a red-cell volume greater than that predicted by weight, body-surface area, or both). The mean values for erythropoietin were 16 mIU per milliliter (range, 8 to 22) in patients with polycythemia rubra vera (n = 24), 30 mIU per milliliter (range, 14 to 123) in patients with secondary erythrocytosis (n = 12), 27 mIU per milliliter (range, 13 to greater than 400) in patients with erythrocytosis of unknown origin (n = 19), and 25 mIU per milliliter (range, 18 to 35) in normal controls (n = 25). The values in the patients with polycythemia rubra vera were lower than those in the other three groups (P less than 0.01, P less than 0.05, and P less than 0.0001, respectively). In subjects with an increased packed red-cell volume but without erythrocytosis (n = 35), the levels of serum erythropoietin were the same as those in normal controls. Among patients with erythrocytosis with an unknown cause, abnormally high serum erythropoietin levels were found in 3 of 19 subjects, and in 1 of these 3 the abnormality was intermittent. Thus, measurement of serum erythropoietin in a single sample may be misleading and may not have high discriminatory value in distinguishing between polycythemia rubra vera and secondary erythrocytosis. This assay is useful in identifying patients with secondary erythrocytosis who have inappropriate erythropoietin secretion.
Adult↗
Treatment of primary proliferative polycythaemia by venesection and low dose busulphan: retrospective study from one centre.
Sixty-five patients with primary proliferative polycythaemia (polycythaemia rubra vera) were followed during the period 1962-83 and analysed retrospectively. Primary control of PCV was by venesection only with low dose busulphan solely as required to keep the platelet count below 400 X 10(9)/l. Median survival was 11.1 years from diagnosis which is equal to or marginally better than with other reported regimens. Vascular causes of death were only a little higher than expected in a comparable normal population. Only deaths from acute leukaemia and myelofibrosis were significantly increased above the normal population incidence. There was no evidence to suggest that these transformations were busulphan induced. Analysis of the incidence of occlusive vascular lesions lends support to an earlier recommendation that the PCV level be maintained below 0.45. No support was found for the possible disadvantages of a predominantly venesection regimen, such as iron deficiency and reactive thrombocytosis. The case is put for this use of low dose busulphan. The data presented would warrant the future inclusion of this therapeutic regime as one limb of a controlled trial.
Adult↗