The toxic oil syndrome.

Hundreds died and thousands were poisoned by rapeseed oil adulterated with aniline and sold illegally in Spain in 1981. The clinical manifestations, now known as the toxic oil syndrome, include pulmonary hypertension and right ventricular hypertrophy plus widespread vascular and neural lesions in other organs. Many of the late deaths ended with a scleroderma-like illness. Because scleroderma involves the heart, an examination was made of the small and large coronary arteries, the neural structures, and the conduction system from 11 victims dying with the toxic oil syndrome. Dense fibrosis, atrionodal junctional hemorrhages, and cystic degeneration of the sinus nodes were present. Small and large coronary arteries exhibited focal fibromuscular dysplasia and a proliferative cystic myointimal degeneration. This latter abnormality was associated with sloughing of the inner wall and embolization of the detached fragment downstream in the same coronary artery. Every heart had many degenerative lesions within nerves, ganglia, and the coronary chemoreceptor. Based upon observations by others with experimental feeding of rapeseed oil containing either high or low erucic acid, it is suggested that this oil must remain a major suspected cause of the toxic oil syndrome, particularly in conjunction with some as yet unexplained facilitative influence by oleoanilids. If this is so, it is important to reexamine the widely recommended use of any rapeseed oil product as a suitable food for humans or animals.

Immunohistochemical analysis of lymphocytes in postmortem study of the heart from fatal cases of the eosinophilia myalgia syndrome and of the toxic oil syndrome.

Inflammatory lesions of coronary arteries and cardiac neural structures are postmortem histopathologic features of both the eosinophilia-myalgia syndrome (EMS) and the toxic oil syndrome (TOS). The inflammation is primarily lymphocytic. For further definition of the lymphocytes, immunohistochemical analysis was carried out in the hearts of three victims of EMS and four victims of TOS. Many CD45RO+ T cells, OPD4+ helper/inducer T (Th) cells, and CD20+ B cells were observed in these neurovascular lesions, notably in the conduction system and the coronary chemoreceptor. T cells were prominent in EMS around nerves, ganglia, and sometimes around arteries. B cells and Th cells, however, were more prominent in TOS around arteries. The percentage of T cells in EMS (59.6 +/- 2.4%) was significantly higher than in TOS (45.0 +/- 4.2%), whereas that of B cells was significantly higher in TOS (27.7 +/- 4.4%) than in EMS (17.5 +/- 1.3%) (p < 0.01, respectively). There was no significant difference between the syndromes in the percentages of Th cells. Therefore cytotoxic/suppressor T cells are more prominent in EMS than in TOS. These findings suggest that (1) cellular immune mechanisms are involved in cardioneuropathy in victims of both EMS and TOS; (2) cell-mediated cytotoxicity directed against chemoreceptor neural structures and sinus nodal myocytes is prominent in EMS; and (3) some humoral factors may also be involved in the pathogenesis of TOS.

Cardiac abnormalities in the toxic oil syndrome, with comparative observations on the eosinophilia-myalgia syndrome.

Early in the course of studies of the Spanish toxic oil syndrome it was recognized that vascular lesions were a major problem, most logically attributable to endothelial damage by the toxic oil. However, most clinical attention has been directed to the pulmonary complications and the evolution into a scleroderma-like illness later. In this study of 11 victims of the toxic oil syndrome careful postmortem studies of the coronary arteries and conduction system and neural structures of the heart demonstrated major injury to all those components of the heart. Obliterative fibrosis of the sinus node in four cases resembled findings in fatal scleroderma heart disease, and in eight the cardiac lesions resembled those of lupus erythematosus. The more impressive pathologic features involved the coronary arteries and neural structures, which were abnormal in every heart. The arterial disease included widespread focal fibromuscular dysplasia, but there was also an unusual myointimal proliferative degeneration of both small and large coronary arteries in five patients, four of whom were young women. In two hearts, portions of the inner wall of the sinus node artery had actually detached and embolized downstream. Coronary arteritis was rarely found. Inflammatory and noninflammatory degeneration of cardiac nerves was widespread. Fatty infiltration, fibrosis and degeneration were present in the coronary chemoreceptor. In most respects these cardiac abnormalities resemble those described in the eosinophilia-myalgia syndrome caused by an altered form of L-tryptophan. In both diseases there is good reason to anticipate more clinical cardiac difficulties than have so far been reported, and even more basis for future concern, especially relative to coronary disease and cardiac electrical instability.

Clinical and pathologic manifestations of pulmonary vascular disease in the toxic oil syndrome.

The toxic oil syndrome in Spain affected greater than 20,000 people. In the initial stages, it was characterized by a respiratory distress syndrome with myalgias and eosinophilia. Pulmonary hypertension developed in 20% of the patients and in many, it has spontaneously regressed. Nevertheless, in a small subgroup, it has progressed to a malignant course of cor pulmonale, leading rapidly to death. Clinical and pathologic features of 40 patients with severe pulmonary hypertension due to the toxic oil syndrome are presented (32 female and 8 male patients; mean age 26 +/- 13 years). The study began in June 1981, which was near the onset of the toxic oil epidemic, and ended in December 1987, greater than 6 years later. The pulmonary hypertension is clinically and pathologically indistinguishable from primary pulmonary hypertension. Direct endothelial injury by the toxic agent is proposed as the initial trigger of this type of pulmonary hypertension, but an interaction between the toxic agent and specific individual susceptibility is probably required in its pathogenesis.

Histologic abnormalities of large and small coronary arteries, neural structures, and the conduction system of the heart found in postmortem studies of individuals dying from the toxic oil syndrome.

Hundreds died and thousands were poisoned by rapeseed oil adulterated with aniline and sold illegally in Spain in 1981. The clinical manifestations, now known as the toxic oil syndrome, include pulmonary hypertension and right ventricular hypertrophy plus widespread vascular and neural lesions in other organs. Many of the late deaths ended with a scleroderma-like illness. Because scleroderma involves the heart, in this study we examined the small and large coronary arteries, neural structures, and conduction system from eight victims dying with the toxic oil syndrome. Dense fibrosis of the sinus node in two hearts resembled changes found in scleroderma. Atrionodal junctional hemorrhages and cystic degeneration of the sinus node present in the other six hearts resembled changes found in lupus erythematosus. Small and large coronary arteries exhibited focal fibromuscular dysplasia and a proliferative cystic myointimal degeneration. This latter abnormality was associated with sloughing of the inner wall and embolization of the detached fragment downstream in the same coronary artery. Every heart had many degenerative lesions within nerves, ganglia, and the coronary chemoreceptor. Both the arterial and neural abnormalities prominently involved the conduction system. Based upon observations by others with experimental feeding of rapeseed oil containing either high or low erucic acid, we suggest that this oil must remain a major suspected cause of the toxic oil syndrome, particularly in conjunction with some as yet unexplained facilitative influence by oleoanilids. If this is so, it is important to reconsider the widely recommended use of any rapeseed oil product as a suitable food for man or other animals.