Latent; clinically latent; completely latent; asymptomatic; completely asymptomatic; totally asymptomatic; clinically expressed; overt; manifest; biochemical and clinically manifest.
Over the years, many terms such as these have been used by doctors/scientists to describe patients’ acute porphyria activity (most notably AIP which has long been the scientific “darling” of the acute porphyrias). In 1994, based on results from urine testing and enzyme assays, a UK study team used the following AIP activity classifications: manifest, latent, normal to assess a study group of twelve patients.Individuals who had a past history of an acute attack of porphyria with documented biochemical confirmation were classified as manifest cases. “Latent cases were defined as individuals who at the time of interview or documented in the past had biochemical evidence of raised urinary porphyrins combined with a porphobilinogen deaminase activity at least 2 standard deviations below the mean but never had a clinical attack. Normals were defined as the family members in whom the PBG deaminase was within normal range, with no evidence of increased excretion of porphyrins in the urine and no clinical history suggestive of an acute attack.”(1)
That same article noted that Dr. Waldenstrom of Sweden (recognized as the “father” of AIP”) had “discovered in asymptomatic relatives the excretion of porphyrin metabolites in the urine [and] described these individuals as latent cases in a 1937 study.”(1) However, two years later, Dr. Waldenstrom reported he had observed “a case where porphyrins could be detected neither in urine nor bile during an attack.”(2) He continued, “The diagnosis: porphyria without porphyrins and chromogen was discussed. Its correctness has now been proved.” He did note, however that “porphyrins and red pigment were found in the [patient’s] urine at a later date, when the patient showed no abdominal symptoms…and added, [t]wo brothers of the patient suffer from typical a.p.”(2) Unfortunately, I was unable to locate the term Dr. Waldenstrom might have applied to the patient he’d observed in an attack that did not excrete porphyrins or chromogen. So, in my book, I referred to my daughter who has suffered severe acute porphyria symptoms and attacks, but hadn’t excreted porphyrins or chromogens as having “atypical” AIP. I knew, as a mother does, that my daughter had an acute porphyria. DNA proved me right. But an APF-associated porph expert claimed her AIP was latent. No thanks to that non-profit “patient advocacy” organization, I was referred to a Swedish born, bred and medically trained pediatric hematologist/AIP expert. She recommended an aggressive treatment program that saved my daughter’s life. Five years later, the geneticist who’d granted the diagnosis revoked it altogether. On top of everything, one non-medico “expert” had the gall to tell my daughter, in writing, no less, “…it can be very difficult to obtain a diagnosis. We have several patients in the same situation with DNA but no attacks.”
There are tens, perhaps hundreds, maybe thousands or more patients the world over who suffer with “porphyria without porphyrins and chromogen.” Acute Porphyria “kicks their butts” every single day. It is well past time that SOMEONE acknowledge Dr. Waldenstrom’s assessment and all these patients that APF et al has erroneously (and caustically) labeled each of them “latent,” “asymptomatic” or “misdiagnosed” and designate an applicable, appropriate term to identify porphyria [attacks] without porphyrins or chromogen.
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