BLOOD SAMPLES AND CHLOROQUINE ASSAY

1227 incidence of anaemia and folate deficiency, suggest that the mean increase in weight following supplementary oral feeding was primarily due to the higher calorie intake. They did not, however, consider other possible reasons or provide the data from which others could draw their own conclusions. Without evidence to the contrary in such a heterogeneous group of patients, an appreciable incidence of potassium, magnesium, or zinc depletion, besides the folate deficiency noted, might well be expected. The nutritional supplements were "enriched with the necessary vitamins and minerals". Reference to the manufacturer’s literature shows that these enrichments included potassium, magnesium, zinc, and folic acid, particularly relevant since one or other in differing ways have been demonstrated as factors in improving calorie utilisation, leucopenia, weight increase, and albumin synthesis. These supplements on the evidence presented cannot be excluded as a reason for the weight and lymphocyte increase noted in some of

their

should be centrifuged (as described above) within 2 h and the plasma should be frozen at -20 to -40°C. In rural areas or in the bush plasma should, if possible, be used as described above within 6 h. If not, whole blood should be kept on ice and then frozen at - 200C to - 40°C. INSERM Unit 13, and Institute of Tropical Medicine

75019

J.

Paris, France

CURING EARLY XEROPHTHALMIA WITHOUT VITAMIN A CONCENTRATE

SIR,-In 1976 The Lancet published a paperl describing a nutrition rehabilitation centre (NRC) in Madurai, South India, for children with ocular signs of vitamin A deficiency and potentially blinding malnutrition. This centre has now been working for 10 years and has cared for 3346 children. The original regimen is still being followed. Children with corneal lesions are dosed orally with 200 000-400 000 IU of vitamin A concentrates in oil and given ample low cost local food including 30-50 g of dark green leafy vegetables, carrots, or papaya to supply sufficient /3-carotene for a young child. Children with conjunctival lesions, conjunctival xerosis, and/or Bitot’s spots are not dosed with vitamin A but rely on (3-carotene from vegetables and fruit in the diet. We have analysed data for children admitted in 1980 to the Madurai centre to see whether ample local food, containing sufficient &bgr;-carotene, is as satisfactory a treatment for children with conjunctival xerophthalmia as it seemed to be at the start. As far as possible comparison has been made between this group and the group with corneal lesions who are given vitamin A.

patients.

-

The literature on Crohn’s disease contains many examples of cohorts of patients which, though provided with ranges, means, and standard deviations, are heterogeneous in pathophysiological terms, making comparisons between published results virtually impossible and type 11 errors possible. A strong argument can be submitted that trials or comparisons should be made on cohorts of patients of more comparable status than is often the case-for example, presenting the data in 5 or 10 year groupings for age and for duration of disease and having groups with comparable incidences of definitive operations and complications-for there is ample evidence of the differing response to Crohn’s disease according to the age of the patient or duration of the disease, particularly with regard to the relative risk of death and recurrence rates.

Sandpits Farm, Walsham-le-Willows, BurySt Edmunds, Suffolk

F. VERDIER LE BRAS F. CLAVIER

Epidemiology, Hôpital Claude Bernard, and

XEROPHTHALMIA CASES IN MADURAI

1980

W.T.COOKE

CHLOROQUINE ASSAY SIR,-Dr Gustafsson and colleagues (Jan 15, p 126) emphasise the BLOOD SAMPLES AND

importance of stating which blood fraction is used for measuring chloroquine blood concentrations so that results are interpreted correctly. We have had similar problems in comparing the published results, which varied according to the prophylactic regimen, method of chloroquine assay, and type of sample. To confirm that a Plasmodium falciparum strain is chloroquine resistant, the clinical inefficacy of the drug must be confirmed by in vitro and in vivo tests, and blood levels of the drug must be

*Children with kwashIorkor excluded owing to impossibility ofassessing weight gain

determined. We measured the blood levels of chloroquine in nine healthy. volunteers (five female, four male) given a daily oral dose of 100 mg chloroquine base for 10 days. 12 h after the last dose, venous blood samples were collected in tubes containing either acid citrate dextrose (ACD) or edetic acid (EDTA). 30 min after collection, the blood was centrifuged at 2000 g for 15 min.1,2 The top two-thirds of plasma and the bottom two-thirds of erythrocytes were collected. The analyses on plasma, erythrocytes, and whole blood were done according to the Bergqvist methodslightly modified. The results (for EDTA samples) varied considerably: whole blood 1245±598 nmol/1 (470-2500); plasma 242± 105 nmol/I (75-380) (or 145 nmol/1 whole blood); and erythrocytes 2068±1147 nmol/1 (860-4430) (or 827 nmol/1 whole blood). It is not always possible to use the samples within 2 h of collection, as recommended by Bergqvist,l so we propose the following conditions to ensure an accurate interpretation of chloroquine assays. Blood should be collected on EDTA (ACD anticoagulant leads to errors due to the blood dilution). In urban areas the blood

o

1

Bergqvist Y, Domeij-Nyberg B. Distribution of chloroquine in human blood cells and its implication for the quantitative determination of the compounds in serum and plasma. J Chromatogr 1983, 272: 137-48. 2 Gustafsson L, Bergqvist Y, Ericsson O, Carson M, Rombo L. Pitfalls in the measurement of chloroquine concentrations. Lancet 1983; i: 126. 3. Bergqvist Y, Frisk-Holmberg M. Sensitive method for the determination of chloroquine and its metabolite desthylchloroquine in human plasma and urine by

high-performance-liquid-chromatography. J Chromatogr 1980; 221:

119-27.

in an

oedematous child.

The two groups are comparable in age, sex, time of stay at the NRC and in weight gain per week (table), but we found that those with corneal lesions had more diarrhoea (63%) than those with conjunctival lesions (48%). The children with corneal lesions also showed more severe malnutrition (grade in, 76%) than those with conjunctival xerophthalmia of whom 57% were grade in. In considering the effect of diet alone on the ocular lesion we have taken the definition given by Sommer et a1.2 A "responsive" Bitot spot is one that improves or is cured within 2 months. Hardly any children with conjunctival xerophthalmia stay for 2 months at the NRC but records show that 46% of Bitot spots were cured and 50% improved during their stay. The percentage cure increased from 3507o if the child stayed 7-14 days, to 100% if the child stayed 30-55

days. The results show that conjunctival xerophthalmia can be cured without vitamin A dosage so long as the child gets enough local food, together with dark green leafy vegetables or fruits rich in &bgr;-carotene. Such treatment should be started at once. It would be helpful if this message could be incorporated in the training of village health workers, their supervisors, and medical staff. 31

Observatory Street,

Oxford OX2 pEW

A. PIRIE

Nutrition Rehabilitation Centre, Government Rajaji Hospital, Madurai, Tamil Nadu, India

S. A. KABIR

Chandra P, Kabir SA, Pine A. A nutrition rehabilitation centre for children with xerophthalmia. Lancet 1976; i. 1120. 2. Sommer A, Emran N, Tjakrasudjatma S. Clinical characteristics of vitamin A responsive and non-responsive Bitot’s spots. Am J Ophthalmol 1980; 90: 160. 1

Venkataswamy G, Krishnamurthy KA,