1. Bring a large pot of salted water to a boil. Add macaroni and cook according to package instructions until al dente. Drain, rinse with cold water and drain again.
2. While pasta is cooking, combine celery, onion, parsley, carrot and tuna in a large bowl. Add cooled macaroni and toss to combine. In a small bowl, whisk mayonnaise, yogurt and vinegar. Season with salt and pepper and whisk. Pour over pasta and toss until well coated. Cover and refrigerate until ready to serve.