Canadian guidelines discuss this lack of clarity and parenthetically point out that "heavy alcohol use" is defined by the National Institute on Alcohol Abuse and Alcoholism as five or more drinks per episode on five or more days during a 30-day period. "The 4-Digit Diagnostic Code" ranking system distinguishes between levels of prenatal alcohol exposure as high risk and some risk. It operationalizes high risk exposure as a blood alcohol concentration (BAC) greater than 100 mg/dL delivered at least weekly in early pregnancy. This BAC level is typically reached by a 55 kg female drinking six to eight beers in one sitting. Unknown exposure
For many adopted or adults and children in foster care, records or other reliable sources may not be available for review. Reporting alcohol use during pregnancy can also be stigmatizing to birth mothers, especially if alcohol use is ongoing. In these cases, all diagnostic systems use an unknown prenatal alcohol exposure designation. A diagnosis of FAS is still possible with an unknown exposure level if other key features of FASD are present at clinical levels. Confirmed absence of exposure
Confirmed absence of exposure would apply to planned pregnancies in which no alcohol was used or pregnancies of women who do not use alcohol or report no use during the pregnancy. This designation is relatively rare, as most people presenting for an FASD evaluation are at least suspected to have had a prenatal alcohol exposure due to presence of other key features of FASD.
Persistent polyclonal B-cell lymphocytosis (PPBL) is an anomaly of the human immune system characterized by mildly elevated levels of white blood cells (called leukocytosis), chronic, stable absolute polyclonal B-cell lymphocytosis, elevated polyclonal IgM and binucleated cells. Although cases of non-smoking women or men have been reported, patients are predominantly young smoking women. Signs and symptoms
Ten percent of patients present with splenomegaly and lymphadenopathy. Some patients report a varying degree of fatigue, consistent with a chronic fatigue syndrome, or postviral fatigue as seen in EBV infections while others remain asymptomatic. Genetics
Genetically, PPBL has been associated with a few unusual genetic characteristics. Among them, it is associated with a particular genetic variant of the human leukocyte antigen called HLA-DR7. This variant is normally present in 26% in the Caucasian population. Chromosome analysis has detected an isochromosome +i(3q), with or without premature chromosome condensation. Also, a t(14;18)(q22;21) bcl-2/IgH rearrangement has been described, as usually seen in follicular lymphoma. Immunologically, peripheral B-cells show more functional IgD+ positive CD27 cells than usual. Prognosis
In the followup of 111 patients, most remained stable and event free. However, two patients developed IgM gammopathy 2 lung cancer; one developed cervical cancer and three developed non-Hodgkins lymphoma. The possibility of developing  a clonal proliferation, malignant lymphoma or secondary solid cancer led the authors to conclude not to classify  PPBL as a benign pathology, as has been previously postulated but rather to recommend a careful and continued clinical and biological longterm follow-up. == References ==