Absence of activating mutations in the EGFR kinase domain in Spanish head and neck cancer patients.

The discovery of kinase domain mutations in the epidermal growth factor receptor gene (EGFR) in never-smoker patients, associated with an increased sensitivity to tyrosine kinase inhibitors (TKIs) such as gefitinib or erlotinib, has been one of the most relevant findings ever in non-small cell lung carcinomas (NSCLC). Since treatment with TKIs has furthermore shown a clinical benefit in head and neck squamous cell carcinoma (HNSCC) patients, we hypothesized that these mutations could also be present in this neoplasia. Current studies looking for EGFR mutations in HNSCC are limited and results are still controversial. In this work, we screened for EGFR tyrosine kinase mutations in tumour DNA obtained from 31 Spanish patients with HNSCC by PCR-single-strand conformational polymorphism analysis. None of the patients displayed a somatic EGFR mutation, previously described in NSCLC, but other DNA sequence variations were found in 9 of 31 HNSCC patients. Accordingly, activating EGFR mutations in HNSCC patients seem to be a rare event in Spanish patients, suggesting that there is little room for the administration of TKIs in HNSCC based on the presence of these mutations. Additional investigations about EGFR amplification are indicated to establish a potential relationship between EGFR overexpression and the response to anti-EGFR therapies.

Ixodes hexagonus is the main candidate as vector of Theileria annae in northwest Spain.

Babesia canis and Babesia gibsoni have, until recently, been considered the only piroplasms that parasitise dogs. However, recent reports indicate that "small" Babesia infections in Spanish dogs are surprisingly frequent and molecular phylogenetic analysis indicates that the infecting agent is closely related to Babesia microti. Because the 18SrDNA sequence was not completely identical to that of B. microti, the new name "Theileria annae" was assigned to the canine agent. No information is available regarding the possible vector of the new piroplasm, T. annae. As part of an effort to identify the tick that may transmit T. annae in northwest Spain we asked veterinary surgeons practising in the region to collect and send to our laboratory ticks from dogs visiting their clinics. Seven hundred and twenty ticks collected from dogs of unknown clinical status during 1998 and 636 ticks collected between November 2001 and March 2002 from 38 dogs infected with T. annae and 131 uninfected dogs were identified. Results from the first study indicated that among the Ixodidae, Ixodes hexagonus clearly predominates over Ixodes ricinus (26.11% versus 6.67%). This observation was consistent with results of the second study, in which I. hexagonus was detected in all infected dogs and 71.8% of non-infected dogs and I. ricinus was not detected in either the infected or non-infected dogs. Results from the 2001-2002 study also indicate that the presence of Dermacentor reticulatus adult females is significantly less frequent among infected than non-infected dogs (OR=0.44; 95% CI: 0.21-0.92). On the other hand, I. hexagonus adult females and males are 6.75 and 4.24 times more likely to be detected among infected than non-infected dogs, respectively, with the association being, in both cases, statistically significant (95% CI: 1.97-23.12 and 1.92-9.36, respectively). I. hexagonus emerges as the main candidate as vector of T. annae because it feeds on dogs more frequently than other ticks and because B. microti is transmitted by Ixodes ticks, both in North America and Europe. In the absence of definitive confirmation of this hypothesis, our observations suggest that I. hexagonus might serve the same role as does Ixodes scapularis (=Ixodes dammini), the vector of B. microti in eastern North America.

Infection of dogs in north-west Spain with a Babesia microti-like agent.

During 1996 a small, ring-shaped, piroplasm was observed in blood smears from 157 dogs in north-west Spain. None of them had previously been in areas endemic for Babesia gibsoni, which was until recently the only small piroplasm known to parasitise dogs. Haematological and serum biochemistry analyses showed that almost all the dogs had an intense regenerative haemolytic anaemia and that in some cases there was evidence of renal failure. A molecular study was made of a sample of the parasite obtained in June 2000. The phylogenetic analysis showed an identity of 100 per cent with the new piroplasm, provisionally denominated as Theileria annae, and 99 per cent with Babesia microti and B. microti-Japan. The results confirm the previous observation of a new form of piroplasm (Theileria annae) which causes disease in dogs in Europe and suggest that it is endemic among the canine population in north-west Spain.

Babesia canis infection in a splenectomized dog.

The present report describes a fatal case of non-experimental babesiosis in a splenctomized 3-year-old fox terrier. A very intense parasitaemia including clusters of up to 16 Babesiae and a prominent haemophagocytic activity were the most relevant findings. A marked leukocytosis, thrombocytopenia and regenerative anaemia were observed. Despite prompt treatment with babesiacidal compounds the condition progressed to acute renal failure and resulted in the death of the animal 48 hours after the onset of symptoms.

Theileria (Babesia) equi and Babesia caballi infections in horses in Galicia, Spain.

The control of equine piroplasmosis is becoming increasingly important to maintain the international market open to the horse industry. The purpose of this study was to demonstrate the occurrence of equine piroplasmosis (Theileria equi and Babesia caballi) in Galicia, north-west Spain, and to compare haematological and serum biochemistry parameters between non-parasitaemic horses and horses parasitaemic with T. equi and B. caballi. Sixty serum samples (control group) were taken from healthy horses pastured on two farms, and examined for evidence of equine T. equi and B. caballi infection by indirect fluorescent antibody test (IFAT). Of the 60 samples, 24 (40%) and 17 (28.3%) samples were positive for T. equi and B. caballi, respectively. Twelve (20%) samples were positive for both parasites. Haematology and serum biochemistry were compared between controls and a series of 36 horses clinically affected by T. equi (25) or B. caballi (11). Compared with the healthy group, there was a 43% and 37% decrease in the haematocrit for T. equi and B. caballi infection, respectively. Parasitaemic horses presented an intense anaemia and serum biochemistry signs of liver damage. The anaemia was more severe in T. equi-infected than in B. caballi-infected horses. Our results suggest that equine piroplasmosis is widespread in the region and is a cause for concern.