Autoimmune haemolysis in childhood and adolescence

The clinico-pathological features of 42 children with autoimmune haemolysis are described. Over 65% of cases were seen before their 5th birthday. In this group males predominated by the ratio of 2.5:1, but in the older children both sexes were equally affected. The incidence decreased from 1 in 188 X 10(3) in young males to 1 in 1,780 X 10(3) in children over 10. Cases were classified serologically. Of particular note was the frequency of Donath-Landsteiner haemolysis which equalled that due to warm autoantibodies; together these groups made up 79% of the total cases. Most haemolytic episodes followed an acute infection. This was frequently mild and often involved the upper respiratory tract; in only 2 patients was haemolysis associated with underlying collagenosis. Typically there was a sudden onset of pallor and malaise; jaundice, splenomegaly and hepatomegaly were found in about half the subjects. Haemoglobinuria was characteristic of Donath-Landsteiner haemolysis. The illness was severe, with Hb levels falling below 6.0 g/dl in 28 patients. Prednisolone, blood transfusion and, where indicated, antibiotics were usually effective in treating the illness, with splenectomy reserved for cases where this treatment was unsatisfactory. In several individuals no treatment was required. Recovery was rapid, and complete recovery occurred in 83% of patients, usually within 6 months. Although 2 patients died, a generally optimistic prognosis can be given, particularly in the absence of an underlying chronic disorder.

Renal Function in Australian Native Rodents

Glomerular filtration rate, renal plasma and blood flow rates, and urea clearance have been measured in five species of native Australian rodents (family Muridae) and the laboratory mouse. The effect of solute loading on two of these species, Notomys alexis and N. mitchellii, has also been investigated. When expressed in mass-independent terms, neither glomemlar filtration rate nor renal blood flow show differences which could be related to preferred habitat. Measurements for the clearance of urea were also similar in all species except Notomys alexis and N. mitchellii, the ratio of this parameter to glomerular filtration rate was lowest in N. alexis, P. australis and M. musculus. Solute loadings of dehydrated N. alexis and N. mitchellii with urea and sodium chloride suggested that the former species may recycle urea to aid in the production of concentrated urine, whereas N. mitchellii may use sodium chloride for this purpose.

Urea metabolism in isolated perfused lungs of the laboratory rat and of a desert rodent, Notomys alexis

1. Using the isolated perfused lung preparation we have demonstrated a low-activity ureolytic enzyme present in rodent lung tissue. The enzyme shares four characteristic features with jack bean urease (EC 3.5.1.5). 2. Ureolytic activity was inhibited by fluoride ions and methionine hydroxamic acid; using the latter inhibitor, the I50 value and maximum inhibition were similar to those reported for jack bean urease. The apparent Km for rat lung urease was similar to the plasma urea level. 3. The low level of urease activity in the rat lung and in that of Notomys alexis, a desert rodent, suggests that the enzyme is not involved in urea excretion, rather that pulmonary ammonia production may influence fluid balance at the alveolus.

Autoimmune hemolysis: mixed warm and cold antibody type

25 patients with mixed autoimmune haemolysis are described; in these cases the combined criteria for warm antibody autoimmune haemolysis and also the cold agglutinin syndrome were present. The direct antiglobulin tests were positive with IgG and complement coating of the red cells. The IgM and IgG components could be separated. The cold autoantibodies were active at 30 degrees C or above and often showed blood group specificity within the Ii system; specificity was not usually evident in the warm component. Haemolysins were found in 18 patients. Serologically, the condition maintained its mixed nature throughout; only 2 cases later changed to a warm type picture. Mixed autoimmune haemolysis was found in all age groups but was more frequent in later life; the male:female ratio was 1:15. The cases were either idiopathic (44%) or secondary; in the latter, systemic lupus erythematosus or lymphoma were the most frequently associated disorders. The patients tended to have severe haemolysis which, although usually responding well to treatment, ran a chronic course with intermittent exacerbations, thus making overall management difficult; plasma exchange may be a useful adjunct to chemotherapy.

Lea blood group substance degradation in the human alimentary tract and urinary Lea in coeliac disease

The Lewis (Lea) blood group substance in alimentary tract liquids is a large molecule. Ileal and jejunal mucosal preparations can act upon it to produce dialysable serologically active Lea. Alimentary tract bacteria cannot produce a similar effect. Plasma, serum and urinary Lea are principally in the form of a dialysable moiety. It is suggested that this dialysable form is produced by mucosal degradation of large-molecule Lea in the alimentary tract. The small-molecule Lea is absorbed, transported in the plasma and then excreted. Both secretor and non-secretor patients with duodenal ulcer and inflammatory bowel disease have normal urinary Lea titres. Non-secretor coeliac patients who have not regenerated normal jejunal mucosa on treatment have significantly reduced urinary Lea titres when compared with healthy individuals. One non-secretor coeliac patient who had regenerated a normal jejunal mucosa on treatment had a normal urinary Lea titre. Coeliac patients have normal titres of salivary Lea.

Erythrocyte autoantibodies, autoimmune haemolysis and pregnancy

The clinical and serological records of 20 pregnant patients with erythrocyte autoantibodies were critically reviewed and analysed. This series, the largest reported, confirmed an association between erythrocyte autosensitization and pregnancy, and suggested that this occurred on an average of 1 in 50,000 pregnancies. The clinical presentation varied from severe haemolytic anaemia to serological abnormalities discovered during the routine testing of well patients; overt haemolysis was present in 7 cases. Treatment was only necessary in 3 patients where the haemolysis was severe. 3 infants were mildly affected with haemolytic disease due to the maternal autoantibodies crossing the placenta but no treatment was needed. The risks to the infant were increased when other active autoimmune conditions (e.g., systemic lupus erythematosus) were present. With early diagnosis and appropriate treatment, outlook for mother and child is good.

Method for the microassay of endogenous creatinine in blood and urine of small murid rodents

The estimation of endogenous creatinine clearance yields information useful to the renal physiologist without the need to introduce a marker compound. The method has been limited in its application to mammalian species of bodyweight 200 g and above due to the blood sample size required. A modification is described whereby this procedure may be applied to animals of bodyweight as low as 25 g. Use of this microassay is illustrated in an investigation of the effect of salt and urea loading on renal function in an Australian desert mouse, Notomys alexis.

Autoimmune haemolysis associated with Donath-Landsteiner antibodies

The clinical pattern of haemolysis associated with Donath-Landsteiner antibodies has undergone a change over the years. In the current study 13 patients developed the acute form of the disease whilst only 1 presented with the classical picture of chronic paroxysmal cold haemoglobinuria. The acute illness typically occurred in young children with a male predominance of about 2.5:1; 10 patients were less than 5 years old. There was often a history of a preceding infection, the onset was sudden, prostration, haemoglobinuria and pallor were prominent. The patients were very ill but rapid and complete recovery usually occurred within a few days; however, 1 patient died. Treatment consisted of rest and warmth; in addition blood transfusion was needed in 7 patients. The chronic disease (which was non-syphilitic in origin) followed a benign course, warmth and avoidance of cold being all that were necessary to maintain the patient's well-being. It is felt that the general term for this disorder should be Donath-Landsteiner haemolysis rather than the traditional paroxysmal cold haemoglobinuria.

Autoimmune haemolysis: an 18-year study of 865 cases referred to a regional transfusion centre

Clinical and serological records of 865 patients with confirmed autoimmune haemolysis (AIH)--a much larger series than any previously reported--were critically reviewed nd analysed. A proposed new classification for AIH based on serological findings differs from traditional classifications in that a new category of "mixed" AIH has been defined in which both "warm" and "cold" autoantibodies are present, and both are capable of causing haemolysis. Patients in this mixed group tend to have severe disease that may run a chronic intermittent course. The presentation of cold agglutinin disease is much more variable than has been seen in previous studies, haemolysis due to low titre autoantibodies being common. The AIH associated with pregnancy, usually considered as being of bad prognosis, is often mild and self limiting in the absence of other associated disorders.

G gamma delta beta thalassaemia and g gamma HPFH (Hb Kenya type): comparison of 2 new cases

Two new cases of G gamma delta beta thalassaemia and G gamma HPFH (Hb Kenya type) have been characterised in detail and compared with regard to haematological data, globin chains biosynthesis, and intracellular distribution of Hb F. The similarities and differences between these two conditions are discussed in relation to the possible underlying defects at the molecular level and to the control of the gamma delta beta gene complex in general.

Total T lymphocytes in primary bronchial carcinoma

Percentage and absolute levels of circulating T lymphocytes were measured in 48 patients with bronchial carcinoma. These were compared with control values from nine healthy adults and 19 age-matched patients with benign disorders. A further 20 patients who had been given postoperative immunotherapy after complete resection of bronchial carcinoma were also studied. There was no significant difference in the mean percentage T cells between the groups. Lymphopenia, however, was a feature of the bronchial cancer patients with metastatic disease. This resulted in a significant diminution of absolute T cells in this group. There is no evidence, with the technique employed in this study, of a total T-cell deficiency in early bronchial carcinoma.

Effect of steroid depletion on the response of toad bladder to vasopressin

1. We have investigated the water transport and short-circuit current (s.c.c.) response to vasopressin (1 mu./ml. and 100 mu./ml.) in isolated toad urinary bladders (Bufo marinus) following overnight incubation in the presence or absence of steroid-containing Ringer solution. 2. The water transport response to the lower dose of vasopressin (1 mu./ml.) was considerably reduced in 'steroid depleted' conditions, wheras the response to the higher dose of vasopressin (100 mu./ml.) was not similarly affected. 3. Aldosterone 3. Aldosterone 3. Aldosterone (10(-7)M) potentiated the water transport response to the lower dose of vasopressin (1 mu./ml.) but had no effect on the response to the higher dose (100 mu./ml.). 4. There was no effect of 'steroid depletion' or aldosterone treatment on the vasopressin s.c.c. response when measured as a percentage increase above basal levels. 5. In 'steroid depleted' conditions vasopressin (1 mu./ml.) maximally stimulated Na+ transport (s.c.c.) but a higher dose of vasopressin (100 mu./ml.) was required for maximum water transport. 6. We have failed to obtain any potentiation effect of corticosterone (10(-7)M) on the water transport or s.c.c. response to vasopressin (1 mu./ml.).