Fecal Calprotectin in assessing Familial Mediterranean Fever Patients

Many inflammatory diseases are prevalent in FMF patients as amyloidosis, Vasculitis and inflammatory bowel disease [12].

Colonoscopy is the gold standard to evaluate gut  mucosal inflammation, However it is a expensive, difficult in children and invasive procedure [13]. So there is a need for a simple non invasive methods for evaluation of mucosal inflammation.

This study aimed to evaluate fecal calprotectin levels in FMF patients as predictor of disease activity.

PATIENTS AND METHODS

We included patients diagnosed with FMF according to the Yalçınkaya criteria 13 in our outpatient clinic at Kafrelsheikh University Hospital  between May 2020 and May 2022.

Patients subjected to history taking, clinical and laboratory evaluation (CBC, CRP, ESR, albumin and Fecal calprotectin). We excluded patients with  other causes of raised FC such as those who took NSAID. The stool samples were stored at  temperature less than 8°C until assay. And we avoided alternating freezing and thawing of the samples. FC ≤50 μg/g was defined as normal, and >50 μg/g as abnormal. Other major causes of raised FC as drugs, infection, inflammatory bowel disease, and amyloidosis were excluded from our study by stool analysis, and by doing endoscopy and colonoscopy followed by histopathology

RESULTS

We included 158 patients. Among them 102 patients were females, and 56 were males. We included 142 patients from Baltium, 12 from Kalian and 4 from Bela. Largest number of patients was diagnosed at age of twenties. Only 5 patients were diagnosed at fifties. 72 patients had more than 6 attacks, 65 patients had 3 to 6 attacks and 21 patients had less than 3 attacks per year. Attacks last in 116 patients for less than 48 hours, while lasting for more than that in 42 patients. Ninety six patients had negative parent consanguinity. 30 patients had history of abdominal surgery. We reported that 130 patients had heterozygous mutation and 28 patients had homozygous mutations confirmed by PCR (Figure 1).

Laboratory evaluation of our patients revealed that WBC and platelet count showed significant difference between Homozygous and Heterozygous groups (P value = 0.000) while ESR, CRP, and Amyloid A levels showed insignificant difference between the two groups Table (1).

Our study reported that FC levels were raised at time of diagnosis above the normal range in both homozygous and heterozygous patients(n Table (2)

ROC analysis of Calprotectin level at time of diagnosis showed significant difference from ESR, CRP and Amyloid A levels with calprotectin value of 100 pg/mL had 96.40% sensitivity and 96.60% Specificity. Table (4) and Figure 2

Statistical analysis

Statistical assessments were performed using SPSS 22 software. We calculate the mean and median for the data with normal and abnormal distribution. For quantitative data, Mann-Whitney and T-tests were used. A chi-square test was used to compare the categorical data. Spearman test was used to find out correlation between quantitative variables. The area under the ROC curve were calculated with a 95% confidence interval (CI). The sensitivity, specificity, positive predictive value, and negative predictive value for optimum cut-off values were in the 95% CI. The significance level was P < 0.05.

Table (1): Showed lab finding in each group.

WBCs: white blood cells, RBCs: red blood cells, Hb: hemoglobin, MCV: mean corpuscular volume. ESR: erythrocyte sedimentation rate, CRP: c reactive protein.

Table (2): Showed calprotectin level and dose of Colachicine needed to give response.

Table (3): ROC analysis values.

ESR: erythrocyte sedimentation rate, CRP: C reactive protein

DISCUSSION

Familial Mediterranean fever (FMF) is autoinflammatory disease  presented by  repeated episodes of fever and serositis. Several markers as CRP, ESR, Amyloid, WBC used to detect systemic inflammation in FMF [14]. However these markers of low sensitivity and specificity for the diagnosis of subclinical intestinal inflammation.

Fc is a marker used to detect inflammation from activated lymphocyte and neutrophiles in intestinal mucosa [15]. However, there are other etiologies to raise its level [16-18]. To exclude other cause of raised FC, we excluded patients with  any chronic disease, those known to have IBD or other intestinal pathology on colonoscopy, those who were using NSAIDs and confirmed that all fecal samples were normal  at the time of raised FC. Many studies addressed the role of FC in rheumatic diseases like  rheumatoid arthritis, scleroderma and Sjögren's syndrome [19,20].

As patients with homozygous mutation have more sever disease than those with heterozygote mutation, our study revealed increase platelet count in homozygotes than heterozygote, Similarly, a previous study revealed increased platelet activation in FMF patients [21].

In the current study, the FC level in the FMF patient was higher than normal (>50 μg/g) in both  FMF  groups and the level were significantly higher in homozygous than heterozygous group.  This is in line with a study by Gucenmezet al. found that Fecal calprotectin level  in FMF patients was significantly higher than in healthy patients [10]. So we suggest that FC can be used for diagnosis and follow up of FMF patients. High level of FMF may be due to chronic inflammation in FMF patients. Another study by Fatma et al concluded that FC is noninvasive simple method for assessing inflammation in childern with FMF patients [22]. The Study limitations were a relatively low number of patients and that it was cross-sectional.

CONCLUSION

Our finding suggests that fecal calprotectin can be used to assess the diagnosis and severity  of  FMF patients. However, future studies are recommended.

Abbreviations:

FC: Fecal calprotectin,

ESR: Erythrocyte sedimentation rate,

FMF: Familial Mediterranean fever

Conflict of interest: None

Funding: No

Ethical considerations:

The study was approved by the Ethics Committee of Kafrelsheikh University . Written informed consent was obtained from the patient.