may mislead research groups and cause some discrepan-
cies in clinical ﬁndings. In addition, the spectroscopic
methods possess poor selectivity, especially in a complex
matrix such as serum or plasma. In a number of research
works, the mixture of derivatization samples was sepa-
rated using a liquid chromatography system and detected
by an ultraviolet or ﬂuorescence detector. The use of a
separation system resolves some of the validation prob-
lems associated with the selectivity of spectroscopic meth-
ods; however, these methods still have low reproducibility
and repeatability. The reasons for this poor validation of
data originate from the high chemical reactivity of MDA,
the strong acidic conditions and high temperature of the
derivatization solutions, cross-reactivity of MDA with
other biochemicals in the biological samples, and the low
stability of standard solutions of MDA and derivatization
reagents, which were comprehensively discussed in a
We strongly recommend that researchers in the ﬁeld
should test the validity of the analytical techniques used
in their determination before reporting the data. Full
details of validation procedures for analytical methods
can be found in the literature.
The validity and reliabil-
ity of biochemical data should be double-checked before
any meta-analysis. Finally, MDA should not be consid-
ered as a speciﬁc indicator of oxidative stress, as there is
some doubts about its reliability.
and M. Khoubnasabjafari
Pharmaceutical Analysis Research Center and Faculty of Pharmacy
Tuberculosis and Lung Disease Research Center, Tabriz
University of Medical Sciences, Tabriz 51664, Iran
Conﬂict of interest: the authors declare that they have no conﬂicts of
Accepted for publication 31 March 2017
1 Shi MH, Wu Y, Li L et al. Chen Meta-analysis of the
association between vitiligo and the level of superoxide
dismutase or malondialdehyde. Clin Exp Dermatol 2017;
2 Zamani-Kalajahi M, Hasanzadeh M, Shadjou N et al.
Electrodiposition of taurine on gold surface and electr-
oxidation of malondialdehye. Surf Eng 2015; 31: 194–
3 Azizi S, Shahrisa A, Khoubnasabjafari M et al. A possible
reason for the low reproducibility of malondialdehyde
determinations in plasma. Bioanalysis 2016; 8: 2179–81.
4 Khoubnasabjafari M, Ansarin K, Jouyban A. Critical
review of malondialdehyde analysis in biological samples.
Curr Pharm Anal 2016; 12:4–17.
5 US Department of Health and Human Services, FDA,
Center for Drug Evaluation and Research, Center for
Veterinary Medicine. Guidance for Industry Bioanalytical
Method Validation. Silver Spring: US FDA. 2001.
Lipoid proteinosis: towards predictive clinical clues
I read with great interest a clinical follow-up letter of
lipoid proteoniosis (LP) by Hamie et al.
published by Clin-
ical and Experimental Dermatology. I thank the authors for
providing the opportunity to discuss these points of a rare
The authors presented 17 cases of LP in 10 Lebanese fam-
ilies, and proposed a number of clinical clues to predict the
clinical course of the disease. However, only a few of the pre-
sented patients had undergone genetic study. Further, as a
general rule, it would be expected that the older the patient,
the more prominent the lesions; however, in the study, most
of the patients at time of examination were in the paediatric
age group (5–16 years), except for one (22 years), and no
details were given about the period between onset of the
lesions and clinical presentation. In addition, there was no
discussion about the length of time for sufﬁcient follow-up.
It is noteworthy that LP is a generalized disorder involving
many organs besides the skin and mucous membranes.
Patients with LP are prone to recurrent skin infections and
episodic swelling of the submandibular or parotid salivary
glands. Hepatosplenomegaly has also been described,
although without evidence of organ dysfunction. The base-
line data of extracutaneous manifestations, except for
neurological signs, was not addressed in the study by Hamie
The authors commented on the patients only, not
including relatives who could have ‘micro-manifestations’.
Moreover, no family pedigree was available in the report to
detect the affected ancestors. In the absence of a genetic
study or family pedigree, the possibility of a de novo mutation
cannot be excluded, even among members of the same fam-
ily. Further, the authors reported correlation of only one
clinical sign with facial lesion and/or neurological manifes-
tations. However, a wide range of clinical heterogeneity may
occur among patients with LP, even within a family or an
isolated patient population.
Yousseﬁan et al.
mutation analysis of the ECM1 gene in 12 patients from 3
Iranian family pedigrees, one of which consisted of 5 genera-
tions. All patients had the same ECM1 mutation, c.507delT,
but they demonstrated widely heterogeneous phenotypes.
Interestingly, some apparently unaffected individuals from
affected families also showed variable symptoms associated
with the disease. After genetic testing of the families, it was
evident that those individuals were genotypically heterozy-
gous for the c.507delT mutation.
The Hamie et al.
study did not provide data available on
the therapeutic history of the patient and whether or not
the previous therapies had an effect on the clinical course.
Thus, the presented data were incomplete and insufﬁcient
for decision-making and establishment of a clinical guide
for dermatologists in assessment of patients with LP.
LP is compatible with a long life. The laryngeal changes
may, however, occasionally be a cause of life-threatening
ª 2017 British Association of Dermatologists
Clinical and Experimental Dermatology (2018) 43, pp319–335