Letter: Chronic cassava toxicity: possible relationship to chronic pancreatic disease in malnourished populations

SPINK1/PSTI mutations are associated with tropical pancreatitis and type II diabetes mellitus in Bangladesh

BACKGROUND & AIMS

Tropical pancreatitis, including tropical calcific pancreatitis and fibrocalculous pancreatic diabetes, is endemic in parts of Asia and Africa. In a preliminary study, we found serine protease inhibitor, Kazal type 1 (SPINK1) mutations in 6 of 8 patients with fibrocalculous pancreatic diabetes in Bangladesh. A more extensive investigation of patients with pancreatic diseases in Bangladesh, including non-insulin-dependent diabetes mellitus, was undertaken.

METHODS

Patients with fibrocalculous pancreatic diabetes (n = 22), tropical calcific pancreatitis (n = 15), and non-insulin-dependent diabetes mellitus (n = 43) and controls (n = 76) from Bangladesh were studied. DNA was extracted, and the SPINK1 gene was sequenced in all patients and 50 controls. Exon 3 was sequenced in an additional 26 controls.

RESULTS

SPINK1 N34S mutations appeared in 1 of 76 controls (1.3%), 12 of 22 patients with fibrocalculous pancreatic diabetes (55%; odds ratio, 83; P < 0.00001), 3 of 15 with tropical calcific pancreatitis (20%; odds ratio, 11.2; P = 0.04), and 6 of 43 with non-insulin-dependent diabetes mellitus (14%; odds ratio, 11.9; P = 0.009). P55S was present in 2 of 76 controls (3%) and in 1 of 22 patients with fibrocalculous pancreatic diabetes (5%; P = not significant). A novel Y54H (160T>C) mutation was identified in 1 of 15 tropical calcific pancreatitis patients.

CONCLUSIONS

In Bangladesh, the SPINK1 N34S mutation increases the risk of several forms of pancreatic disease, including fibrocalculous pancreatic diabetes, tropical calcific pancreatitis, and non-insulin-dependent diabetes mellitus.

Tropical calcific pancreatitis

Tropical calcific pancreatitis is a special type of chronic pancreatitis that has features quite different from those of alcoholic pancreatitis and is seen almost exclusively in tropical countries. It is characterized by recurrent severe pain in the abdomen, insulin-requiring but ketosis-resistant diabetes and large pancreatic calculi in malnourished male adolescents. The clinical course of tropical calcific pancreatitis is protracted with malnutrition, recurrent infections and poorly controlled diabetes. Pancreatic cancer may complicate the natural course in up to 10% of cases. However, in the community a much milder form of the disease occurs with a female preponderance and a prevalence of 0.13% or one in 793. Malnutrition with deficiency of proteins and micronutrients with antioxidant properties and food-based toxins, such as cassava, which contain cyanogenic glycosides have been suspected as possible aetiological factors. Impaired immune response, a presumed infection (possibly viral) and genetic susceptibility are some of the other factors suspected in the aetiopathogenesis of this disease. Besides controlling diabetes with insulin, relief from pain is obtained by the administration of analgesics and pancreatic enzymes and, in severe cases, by performing endoscopic or surgical decompression of dilated pancreatic ducts with removal of pancreatic calculi.

Effects of prolonged ethanol intake and malnutrition on rat pancreas

Nutritional factors, especially the protein and fat content of the diet, may change pancreatic morphology after ethanol induced injury. This study was performed to delineate the combined effects of a low fat diet and longterm ethanol ingestion on the rat pancreas. Male Sprague-Dawley rats were maintained with five different diets for 12 weeks and the pancreas removed on the day they were killed. Rats fed a very low fat diet without ethanol (5% of total calories as lipid) developed malnutrition, pancreatic steatosis, and reduction in zymogen granules content. Animals fed a 35% lipid diet with ethanol also developed pancreatic steatosis but changes in zymogen granules content were not detected. Both malnutrition and longterm ethanol consumption increased pancreatic cholesterol ester content, and their effects were additive. Pancreatic steatosis was accompanied with hypercholesterolaemia. Amylase, lipase, and cholesterol esterase content were reduced in malnourished rats; but longterm ethanol ingestion, regardless of the nutritional state, increased lipase content and decreased amylase. It is suggested that high serum cholesterol concentrations and increased pancreatic lipase activity could cause accumulation of cholesterol esters in acinar cells. Fat accumulation in the pancreas has been reported as the earliest histopathological feature in alcoholic patients and may be responsible for cytotoxic effects on the acinar cells at the level of the cell membrane. Although it is difficult to extrapolate results in this animal study to the human situation, the results presented in this work might explain the higher incidence of pancreatitis is malnourished populations as well as in alcoholic subjects that is reported in dietary surveys.

Presence of autoimmunity to pancreatic antigens in a patient with fibrocalculous pancreatic diabetes

A case of fibrocalculous pancreatic diabetes (FCPD) is reported for which antibody and cellular immune characteristics were determined. The patient, a Thai woman, had serum islet cell antibodies (ICA) that were detected by both immunoperoxidase staining and an indirect enzyme-linked immunosorbent assay (ELISA). Serum anti-human insulin antibodies were negative by a displacement ELISA. Lymphoproliferation assay against pancreatic antigen prepared from a blood group O cadaveric donor was positive. Increased CD8+ lymphocytes were observed using direct immunofluorescence staining and flow cytometry. CD4+ T lymphocytes, B lymphocytes and NK cells were within normal levels. These findings provide evidence for autoimmunity to pancreatic antigens in a patient with fibrocalculous pancreatic diabetes.

Association of hyperglycemia with dietary cyanogen and socio-economic level. The study of rural communities in south-east Nigeria

An association of asymptomatic hyperglycemia with dietary cyanogens and socio-economic level was ascertained in 2,000 volunteers in rural communities in South-East Nigeria. The staples of the poor consisted of one or two bulky carbohydrate meals (derivatives of different species of cocoyam, cassava, yam and maize) eaten with vegetable soup in palm oil, melon seeds, snail, occasional meat and fish. The diet of the high income class included also beans, rice and more animal proteins. Alcohol (mainly palm wine) was consumed only occasionally. The subjects were divided into male and female and were age-matched into various age groups. Anthropometric data of each subject was obtained alongside the family history and socio-economic status. The subjects were further divided into low income vis-a-vis high income groups. All the subjects were normal volunteers, ambulatory, asymptomatic and free from chronic or acute illness. The fasting capillary whole blood glucose (FBG) and 2-h blood glucose following a 75 g oral glucose tolerance test (OGTT) of each subject were measured. The body mass index (BMI) and dental caries scoring of each subject were also determined. The FBG levels and 2-h blood glucose following OGTT were significantly elevated in all subjects particularly in the low income groups except in the under 18-year group. The increases were observed in males and females although glucose levels were lower in the female age group. However, diagnosis of impaired glucose tolerance according to WHO criteria was present in both income groups. The BMI increased as the age increased particularly in the low income groups. There was a strong relationship between age, FBG, IGT and dental caries, respectively in the population. It is concluded that there was strong relationship between poverty, asymptomatic hyperglycemia, and impaired glucose tolerance in the area where cyanogen in diet was higher while there was marginal animal protein in the diet of the poor.

Case-control study on risk factors associated with fibrocalculous pancreatic diabetes

We investigated the relation between fibrocalculous pancreatic diabetes and cassava consumption in a case-control study, in which 31 cases of pancreatic diabetes were compared with 45 non-diabetic control subjects who had no pancreatic calcification. Risk of diabetes was not related to cassava consumption. We also observed no increased risk of fibrocalculous pancreatic diabetes associated with alcohol consumption, history of gallbladder and biliary tract diseases, ascariasis, and family history of diabetes. Lower monthly income, farmer occupation, rural residence, and low BMI were significantly (p less than 0.05) related to pancreatic diabetes. Our data suggest that consumption of cassava may not be an important risk factor for pancreatic diabetes. With limited sample size, however, cassava consumption could not be excluded as one possible cause of fibrocalculous pancreatic diabetes.

Effect of parental malnutrition on enzyme content of rat pancreas

The aim of this study was to assess in rat pups the influence of protein diets ingested by their mothers during gestation and lactation on the enzyme content of the pancreas of the offspring. Rat pups born of either well-nourished mothers or of mothers fed a diet moderately restricted in protein (9% casein w/w) were studied. After weaning, the pups were fed on one of three diets: a well-balanced diet, a 5% casein diet (protein restricted), or a well-balanced diet of a similar caloric value as the protein-restricted diet (pair-fed rat pups). The pups were sacrificed after intervals of one to 25 weeks after weaning. The results showed that the enzyme content of the pancreas increased progressively with time in pups born of malnourished mothers, particularly in pups fed the protein-restricted diet. This suggests prolonged maturation of the pancreas. Pups fed the 5% casein diet had a decreased amylase content per milligram of DNA but not of other enzymes. Malnutrition in the mother increased the ratio of enzymes to DNA and the total pancreatic enzyme content at different times after weaning, indicating that maternal malnutrition had a prolonged effect on the pancreatic enzyme content of the pups' pancreas. This mechanism could play a role in the pathogenesis of tropical chronic calcific pancreatitis in man and explain some of the geographic differences in the incidence of the disease.

Etiology of chronic calcifying pancreatitis in Brazil: a report of 329 consecutive cases

The authors observed 329 consecutive cases of chronic calcifying pancreatitis (CCP) from January 1963 to January 1986. Alcoholism was the etiological agent in 282 cases (86%). In 34 patients (10%) no cause was detectable (idiopathic). Malnutrition was responsible for 10 cases (3%) and chronic familial pancreatitis was diagnosed in 3 cases (0.9%). The mean age at the apparent onset of symptoms was 36.5 +/- 10.5 for the alcoholics, 22.6 +/- 15.4 in the idiopathic cases and 7.3 +/- 3.0 for the nutritional etiology patients. Mean age differences are statistically significant for the 3 groups. Pancreatic calcifications were found in 224 alcohol-induced cases (79%), in 32 idiopathic cases (94%), in 8 patients with malnutrition (80%) and in one patient with familial pancreatitis (33%). All cases of nutritional etiology presented severe protein-caloric deficiencies with edema, and none complained of pain, but 9 had pancreatic insufficiency. Mean daily ethanol intake for the alcohol-addicted patients was 396.6 +/- 286 g (range 80-1664 g) with the onset of alcoholism at 19.1 +/- 6.8 yr old and 20.8 +/- 8.3 (4-44) yr of alcohol indulgence. Pancreatic carcinoma developed in 7 cases. Six cases of chronic pancreatitis were seen among relatives in the group with CCP of alcoholic etiology.

Exocrine pancreatic function of children from the Ivory Coast compared to French children. Effect of kwashiorkor

One hundred nineteen children, either French or from the Ivory Coast, aged 1-8 years, were submitted to pancreatic function testing by duodenal aspiration. Trypsin, chymotrypsin, lipase, phospholipase, amylase, volume, bicarbonate, chloride, and calcium were estimated before and after an intravenous injection of 1 CU secretin + 3 CHR units pancreozymin per kilogram of body weight. Sixty-two patients were normal European children, and 11 were normal African children. Twenty-five African children presented with kwashiorkor and 10 African children had presented with kwashiorkor but had recovered at the time of the test. Three cases of recurrent kwashiorkor are also included. In the normal group of African children, phospholipase concentration, volume, and bicarbonate were significantly decreased but chymotrypsin and trypsin concentrations were not, when compared to the normal European population. In kwashiorkor patients, lipase, amylase, phospholipase, and chymotrypsin concentration were significantly decreased compared to normal Africans. Trypsin, volume, and bicarbonate were not affected. These modifications disappeared after refeeding. In cases of recurrent kwashiorkor, all enzymes, including trypsin, were decreased. Calcium was never modified. These modifications were very different from those observed in chronic alcoholic and hypercalcemic pancreatitis. In a two-year study, chronic calcifying pancreatitis (CCP) was diagnosed in 14 patients (13 males), hospitalized in Abidjan. The mean age at onset of the disease was 41 years (SD 12.71), which is very similar to European cases. The most frequent cause was alcoholism, as in Occidental countries. The nutrition of the population was low in protein, calories being provided mostly by manioc, but no apparent symptoms of malnutrition were observed in the parents of our patients.(ABSTRACT TRUNCATED AT 250 WORDS)